IMPORTANT ELECTRICAL INFORMATION (Long!)
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,396
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I would like to make a few comments on your problem. This is for anyone else that wants the dealer to fix their C5's
First off,,corvettes are NOT normally damaged or effected by driving in adverse weather. It may seem like it is but, I think its is more coincidental than any thing else. If rain does effect it, it's pointing you to the problem more than causing it. Your REDUCED ENGINE POWER was most likely caused by the LOW VOLTAGE problem. The PCM,BCM and all the other modules will start shutting down at 9 VDC and when you close to that voltage, anything can cause the PCM to not be happy and enter REDUCED ENGINE POWER.
To examine what is happening with your charging system you need a voltmeter to measure DC Voltage in a few different areas. First measure the voltage AT THE BATTERY with the car OFF! Write it down. It should be nominally 12.5 VDC -13.5 VDC. The older your battery is the lower that voltage will be. If your in the 11.0-11.5 VDC after it sits over night, its about time for a new battery. If its just low from sitting over a long period of time or repeated cranking, charge it and recheck it after it sits over night.
If you think your battery is at fault, have it tested at a parts place. Make sure its fully charged before you take it there for testing.
Next,,,read the voltage on the LARGE connector on the back of the alternator. (car OFF, engine OFF) It should read the SAME value as the voltage on the battery terminals. That large red wire goes to the starter solenoid. The main + battery cable also connects to the same terminal on the starter solenoid.
Have someone START the engine while you, READ the battery voltages AT THE BATTERY,,, before, during and after the engine cranks and runs. Once its running, read the voltages on the battery terminals.
You should see the 12.5 VDC -13.5 VDC before starting, 11-12 VDC during the start and 13.5 -14.5 during the engine run charging phase. Then, check the voltage at the alternator. It should be that same as battery voltage.
While its running, Apply some loads like the head lights on high beams, HVAC blower on high, read defroster, ect.... and read everything again.
Voltages should remain in the 13.5 -14.5 zone with out an issue.
If the voltage on the field terminal is LOW or non existent,,,,you could have a problem with the battery cables, starter solenoid, wire from the battery to the starter.
My guess is,,,you have loose,dirty or damaged battery cables, OR loose dirty or damaged connections on the starter solenoid or burnt or loose connection on the alternator.
The PCM tells the alternator when and how much to charge. The small connector on top of the alternator controls that function. It have to be clean and tight with good connections.
I hate when the dealer (pronounced "STEALER" ) throws parts at the problem with your wallet!
First off,,corvettes are NOT normally damaged or effected by driving in adverse weather. It may seem like it is but, I think its is more coincidental than any thing else. If rain does effect it, it's pointing you to the problem more than causing it. Your REDUCED ENGINE POWER was most likely caused by the LOW VOLTAGE problem. The PCM,BCM and all the other modules will start shutting down at 9 VDC and when you close to that voltage, anything can cause the PCM to not be happy and enter REDUCED ENGINE POWER.
To examine what is happening with your charging system you need a voltmeter to measure DC Voltage in a few different areas. First measure the voltage AT THE BATTERY with the car OFF! Write it down. It should be nominally 12.5 VDC -13.5 VDC. The older your battery is the lower that voltage will be. If your in the 11.0-11.5 VDC after it sits over night, its about time for a new battery. If its just low from sitting over a long period of time or repeated cranking, charge it and recheck it after it sits over night.
If you think your battery is at fault, have it tested at a parts place. Make sure its fully charged before you take it there for testing.
Next,,,read the voltage on the LARGE connector on the back of the alternator. (car OFF, engine OFF) It should read the SAME value as the voltage on the battery terminals. That large red wire goes to the starter solenoid. The main + battery cable also connects to the same terminal on the starter solenoid.
Have someone START the engine while you, READ the battery voltages AT THE BATTERY,,, before, during and after the engine cranks and runs. Once its running, read the voltages on the battery terminals.
You should see the 12.5 VDC -13.5 VDC before starting, 11-12 VDC during the start and 13.5 -14.5 during the engine run charging phase. Then, check the voltage at the alternator. It should be that same as battery voltage.
While its running, Apply some loads like the head lights on high beams, HVAC blower on high, read defroster, ect.... and read everything again.
Voltages should remain in the 13.5 -14.5 zone with out an issue.
If the voltage on the field terminal is LOW or non existent,,,,you could have a problem with the battery cables, starter solenoid, wire from the battery to the starter.
My guess is,,,you have loose,dirty or damaged battery cables, OR loose dirty or damaged connections on the starter solenoid or burnt or loose connection on the alternator.
The PCM tells the alternator when and how much to charge. The small connector on top of the alternator controls that function. It have to be clean and tight with good connections.
I hate when the dealer (pronounced "STEALER" ) throws parts at the problem with your wallet!
i am currently having problems with my 01 vette. about a month ago it started raining and that night i went to move my car and i received a l "LOW VOLTAGE, REDUCED ENGINE POWER" with the check engine light on and it seemed sluggish, like i would be pressing the gas but the car wasn't reacting to it at all. the following morning i started the car and there was no problems. about a week later the problem came back, so i had the dealership take a look at it, they said i had a bad alternator, so i had that replaced. a few days later same problem. replaced battery since i still had the original one. worked fine for a few more days. went to start it up same problem. when i have the key in and i attempt to sarrt the car none of my gages move except for the battery one and it tries to move but only gets to like 6 volts and comes back down and will continue to do it, it also makes a buzzing noise. but if i leave it alone for a little bit it starts right back up. this problem is intermitent, and my friend and i are going to locate the grounds tomorrow and clean them out. also i am having problems with my signals they will be working just fine then all of a sudden stop, and stop working for a while then start.
6th Gear
Joined: Jan 2008
Posts: 6
Likes: 0
I would like to make a few comments on your problem. This is for anyone else that wants the dealer to fix their C5's
First off,,corvettes are NOT normally damaged or effected by driving in adverse weather. It may seem like it is but, I think its is more coincidental than any thing else. If rain does effect it, it's pointing you to the problem more than causing it. Your REDUCED ENGINE POWER was most likely caused by the LOW VOLTAGE problem. The PCM,BCM and all the other modules will start shutting down at 9 VDC and when you close to that voltage, anything can cause the PCM to not be happy and enter REDUCED ENGINE POWER.
To examine what is happening with your charging system you need a voltmeter to measure DC Voltage in a few different areas. First measure the voltage AT THE BATTERY with the car OFF! Write it down. It should be nominally 12.5 VDC -13.5 VDC. The older your battery is the lower that voltage will be. If your in the 11.0-11.5 VDC after it sits over night, its about time for a new battery. If its just low from sitting over a long period of time or repeated cranking, charge it and recheck it after it sits over night.
If you think your battery is at fault, have it tested at a parts place. Make sure its fully charged before you take it there for testing.
Next,,,read the voltage on the LARGE connector on the back of the alternator. (car OFF, engine OFF) It should read the SAME value as the voltage on the battery terminals. That large red wire goes to the starter solenoid. The main + battery cable also connects to the same terminal on the starter solenoid.
Have someone START the engine while you, READ the battery voltages AT THE BATTERY,,, before, during and after the engine cranks and runs. Once its running, read the voltages on the battery terminals.
You should see the 12.5 VDC -13.5 VDC before starting, 11-12 VDC during the start and 13.5 -14.5 during the engine run charging phase. Then, check the voltage at the alternator. It should be that same as battery voltage.
While its running, Apply some loads like the head lights on high beams, HVAC blower on high, read defroster, ect.... and read everything again.
Voltages should remain in the 13.5 -14.5 zone with out an issue.
If the voltage on the field terminal is LOW or non existent,,,,you could have a problem with the battery cables, starter solenoid, wire from the battery to the starter.
My guess is,,,you have loose,dirty or damaged battery cables, OR loose dirty or damaged connections on the starter solenoid or burnt or loose connection on the alternator.
The PCM tells the alternator when and how much to charge. The small connector on top of the alternator controls that function. It have to be clean and tight with good connections.
I hate when the dealer (pronounced "STEALER" ) throws parts at the problem with your wallet!
First off,,corvettes are NOT normally damaged or effected by driving in adverse weather. It may seem like it is but, I think its is more coincidental than any thing else. If rain does effect it, it's pointing you to the problem more than causing it. Your REDUCED ENGINE POWER was most likely caused by the LOW VOLTAGE problem. The PCM,BCM and all the other modules will start shutting down at 9 VDC and when you close to that voltage, anything can cause the PCM to not be happy and enter REDUCED ENGINE POWER.
To examine what is happening with your charging system you need a voltmeter to measure DC Voltage in a few different areas. First measure the voltage AT THE BATTERY with the car OFF! Write it down. It should be nominally 12.5 VDC -13.5 VDC. The older your battery is the lower that voltage will be. If your in the 11.0-11.5 VDC after it sits over night, its about time for a new battery. If its just low from sitting over a long period of time or repeated cranking, charge it and recheck it after it sits over night.
If you think your battery is at fault, have it tested at a parts place. Make sure its fully charged before you take it there for testing.
Next,,,read the voltage on the LARGE connector on the back of the alternator. (car OFF, engine OFF) It should read the SAME value as the voltage on the battery terminals. That large red wire goes to the starter solenoid. The main + battery cable also connects to the same terminal on the starter solenoid.
Have someone START the engine while you, READ the battery voltages AT THE BATTERY,,, before, during and after the engine cranks and runs. Once its running, read the voltages on the battery terminals.
You should see the 12.5 VDC -13.5 VDC before starting, 11-12 VDC during the start and 13.5 -14.5 during the engine run charging phase. Then, check the voltage at the alternator. It should be that same as battery voltage.
While its running, Apply some loads like the head lights on high beams, HVAC blower on high, read defroster, ect.... and read everything again.
Voltages should remain in the 13.5 -14.5 zone with out an issue.
If the voltage on the field terminal is LOW or non existent,,,,you could have a problem with the battery cables, starter solenoid, wire from the battery to the starter.
My guess is,,,you have loose,dirty or damaged battery cables, OR loose dirty or damaged connections on the starter solenoid or burnt or loose connection on the alternator.
The PCM tells the alternator when and how much to charge. The small connector on top of the alternator controls that function. It have to be clean and tight with good connections.
I hate when the dealer (pronounced "STEALER" ) throws parts at the problem with your wallet!
i think i have found the problem. i will be putting a new key switch in because the 6v problem happens when i turn it on and off. but when i wiggle the keys it seems like it makes "contact" and all my gauges cycle and the car starts right up. i can controll the problem now with wiggling and jerking the key. i will do one problem at a time. i also have the service active handling. i found good guides on this and i will attempt that after the key switch.
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,396
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
i think i have found the problem. i will be putting a new key switch in because the 6v problem happens when i turn it on and off. but when i wiggle the keys it seems like it makes "contact" and all my gauges cycle and the car starts right up. i can controll the problem now with wiggling and jerking the key. i will do one problem at a time. i also have the service active handling. i found good guides on this and i will attempt that after the key switch.
Those ignition switches have really problematic lately. This is the THIRD one this month I have seen go bad. They supply voltage to a LOT of power up circuits so,,,,if one of the contacts inside is bad, it will effect a lot of different things like dash lights, IPC issues, etc................ Take that sucker apart and shhow us what went bad!
Let us know what you find out.
BC
Drifting
Joined: Jul 2002
Posts: 1,730
Likes: 14
From: Tucson AZ
Bill, Thanks for responding to my PM the other day. Think I have a doosey for you...... 
The car... '98 aith A4.
About 9-months ago my car was showing service ABS, TC and AH on DIC. I don't recall the exact codes, think it was C1214. So I did a forum search, talked to Brandon at ABSFixer, he said he could fix it, sent it off, got it back, no codes, problem solved.
Fast foward 6-months. Started getting the same service ABS, TC and AH on DIC. Initally it was intermittant and slowly became constant. Eventually if I do not turn the TC off at start-up when I drive away the rear brakes start pulsating like the ABS is engaging while I'm driving (happens within the first 50 yards).
Ah-ight, back to the shop....
Now I'm spitting this out best I can recall so if I say something "technically inept", remember I'm a desk jockey.....and please still help me!!
Codes were C1255 (internal EBTCM failure), C1226 (R/F wheel speed sensor) and C1227 (L/F wheel speed sensor). Based on what I read in the forum I had the tech check all the grounds, the female pin connector the EBTCM to the harness, yada, yada, yada. Call Brandon, he offers to refund me my money?? I said, "why?", he fixed the problem it had 9-months ago which is different from what it's doing now. If it had been code C1255 9-months ago he would have told me he couldn't fix it. So anyway, Brandon is stand-up, I don't think my codes are related to the ones earlier and I don't think he owes me my money back.
So we decide the EBTCM is bad and get a new one from the stealership. We hold off doing anything with the wheel speed sensors because we think it's possible the C1255 was causing them. Replace the EBTCM, reflash the PCM and the wheel speed sensor codes are still there. The R/F is all the time, the L/F is more intermittant.
So we get a new R/F wheel speed sensor and schlap it on. He spins the R/F wheel with the car in the air while the Tech II is plugged in and the sensor is sending info. He OHM'd from the sensor back to the EBTCM and it's good.
Put her back together, drop her down and take her for a spin with the Tech II plugged in. Get to the driveway and it sets C1226 and C1227.
Scratch head and pop beer.....
The car... '98 aith A4.
About 9-months ago my car was showing service ABS, TC and AH on DIC. I don't recall the exact codes, think it was C1214. So I did a forum search, talked to Brandon at ABSFixer, he said he could fix it, sent it off, got it back, no codes, problem solved.
Fast foward 6-months. Started getting the same service ABS, TC and AH on DIC. Initally it was intermittant and slowly became constant. Eventually if I do not turn the TC off at start-up when I drive away the rear brakes start pulsating like the ABS is engaging while I'm driving (happens within the first 50 yards).
Ah-ight, back to the shop....
Now I'm spitting this out best I can recall so if I say something "technically inept", remember I'm a desk jockey.....and please still help me!!
Codes were C1255 (internal EBTCM failure), C1226 (R/F wheel speed sensor) and C1227 (L/F wheel speed sensor). Based on what I read in the forum I had the tech check all the grounds, the female pin connector the EBTCM to the harness, yada, yada, yada. Call Brandon, he offers to refund me my money?? I said, "why?", he fixed the problem it had 9-months ago which is different from what it's doing now. If it had been code C1255 9-months ago he would have told me he couldn't fix it. So anyway, Brandon is stand-up, I don't think my codes are related to the ones earlier and I don't think he owes me my money back.
So we decide the EBTCM is bad and get a new one from the stealership. We hold off doing anything with the wheel speed sensors because we think it's possible the C1255 was causing them. Replace the EBTCM, reflash the PCM and the wheel speed sensor codes are still there. The R/F is all the time, the L/F is more intermittant.
So we get a new R/F wheel speed sensor and schlap it on. He spins the R/F wheel with the car in the air while the Tech II is plugged in and the sensor is sending info. He OHM'd from the sensor back to the EBTCM and it's good.
Put her back together, drop her down and take her for a spin with the Tech II plugged in. Get to the driveway and it sets C1226 and C1227.
Scratch head and pop beer.....
Last edited by BobJ; Feb 15, 2008 at 05:58 PM.
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,396
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Bill, Thanks for responding to my PM the other day. Think I have a doosey for you......
The car... '98 aith A4.
About 9-months ago my car was showing service ABS, TC and AH on DIC. I don't recall the exact codes, think it was C1214. So I did a forum search, talked to Brandon at ABSFixer, he said he could fix it, sent it off, got it back, no codes, problem solved.
Fast foward 6-months. Started getting the same service ABS, TC and AH on DIC. Initally it was intermittant and slowly became constant. Eventually if I do not turn the TC off at start-up when I drive away the rear brakes start pulsating like the ABS is engaging while I'm driving (happens within the first 50 yards).
Ah-ight, back to the shop....
Now I'm spitting this out best I can recall so if I say something "technically inept", remember I'm a desk jockey.....and please still help me!!
Codes were C1255 (internal EBTCM failure), C1226 (R/F wheel speed sensor) and C1227 (L/F wheel speed sensor). Based on what I read in the forum I had the tech check all the grounds, the female pin connector the EBTCM to the harness, yada, yada, yada. Call Brandon, he offers to refund me my money?? I said, "why?", he fixed the problem it had 9-months ago which is different from what it's doing now. If it had been code C1255 9-months ago he would have told me he couldn't fix it. So anyway, Brandon is stand-up, I don't think my codes are related to the ones earlier and I don't think he owes me my money back.
So we decide the EBTCM is bad and get a new one from the stealership. We hold off doing anything with the wheel speed sensors because we think it's possible the C1255 was causing them. Replace the EBTCM, reflash the PCM and the wheel speed sensor codes are still there. The R/F is all the time, the L/F is more intermittant.
So we get a new R/F wheel speed sensor and schlap it on. He spins the R/F wheel with the car in the air while the Tech II is plugged in and the sensor is sending info. He OHM'd from the sensor back to the EBTCM and it's good.
Put her back together, drop her down and take her for a spin with the Tech II plugged in. Get to the driveway and it sets C1226 and C1227.
Scratch head and pop beer.....
The car... '98 aith A4.
About 9-months ago my car was showing service ABS, TC and AH on DIC. I don't recall the exact codes, think it was C1214. So I did a forum search, talked to Brandon at ABSFixer, he said he could fix it, sent it off, got it back, no codes, problem solved.
Fast foward 6-months. Started getting the same service ABS, TC and AH on DIC. Initally it was intermittant and slowly became constant. Eventually if I do not turn the TC off at start-up when I drive away the rear brakes start pulsating like the ABS is engaging while I'm driving (happens within the first 50 yards).
Ah-ight, back to the shop....
Now I'm spitting this out best I can recall so if I say something "technically inept", remember I'm a desk jockey.....and please still help me!!
Codes were C1255 (internal EBTCM failure), C1226 (R/F wheel speed sensor) and C1227 (L/F wheel speed sensor). Based on what I read in the forum I had the tech check all the grounds, the female pin connector the EBTCM to the harness, yada, yada, yada. Call Brandon, he offers to refund me my money?? I said, "why?", he fixed the problem it had 9-months ago which is different from what it's doing now. If it had been code C1255 9-months ago he would have told me he couldn't fix it. So anyway, Brandon is stand-up, I don't think my codes are related to the ones earlier and I don't think he owes me my money back.
So we decide the EBTCM is bad and get a new one from the stealership. We hold off doing anything with the wheel speed sensors because we think it's possible the C1255 was causing them. Replace the EBTCM, reflash the PCM and the wheel speed sensor codes are still there. The R/F is all the time, the L/F is more intermittant.
So we get a new R/F wheel speed sensor and schlap it on. He spins the R/F wheel with the car in the air while the Tech II is plugged in and the sensor is sending info. He OHM'd from the sensor back to the EBTCM and it's good.
Put her back together, drop her down and take her for a spin with the Tech II plugged in. Get to the driveway and it sets C1226 and C1227.
Scratch head and pop beer.....
I applaud you!
Thats some of the BEST troubleshooting and repair work Ive seen in a while! You did EXACTLY everything correct!As I was reading your reply I was shaking my head
that what needed to be done! Im glad you got a NEW EBTCM. Thats what was needed. The micro processor in the BCM went bad! Mine did the same thing. NO ONE can fix that!
Again,,,good job,, desk jockey! 
Now,,,,to clear your wheel speed sensor DTCs your going to need to CAREFULLY examine some harness connectors! Believe me, Ive been here!
Find a spare MALE PIN. The dealer should have a connector repair kit that has spare pins. I took mine out of a bad emergency flasher switch.
Once you have a MALE PIN, separate the FEMALE connectors in the wheel speed sensor harnesses and insert the male pins into the female pins. There should be a FIRM grip when the pin is inserted and removed!! If the grip is NOT firm,,,,,replace the female connector
Here is a pic of TWO female wheel speed harness connectors. The one on the left is NEW and the one on the right is BAD.
The bad one was the female harness connector on the cross member.
Here is a picture of the JUMPER HARNESS that runs from the wheel speed sensor to the female harness connector on the cross member.
The jumper harness can go bad also.
Here is a brand new connector with a pigtail.
Unless you test the female connections with a pin,,,,you will chase your tail!
BC
BC
Drifting
Joined: Jul 2002
Posts: 1,730
Likes: 14
From: Tucson AZ
Thanks alot Bill. You know "in theory" the connector makes sense because when we were driving the car the codes would go off when we went down a driveway, or hit a bump. Bad connection possibly??
I'll post back when we finger it out......
I'll post back when we finger it out......
Drifting
Joined: Jul 2002
Posts: 1,730
Likes: 14
From: Tucson AZ
Car is fixed....and it's something completely different!!
I replaced the battery about 6-months ago. It had expanded, broke open and dripped acid. The loom for the main wiring harness was compromised eating through the insulation of two wires.
I still think I needed the EBTCM, not sure about the wheel speed sensor. Oh well, it's on there now and you can't send those parts back!!
Thanks for the help Bill!
I replaced the battery about 6-months ago. It had expanded, broke open and dripped acid. The loom for the main wiring harness was compromised eating through the insulation of two wires.
I still think I needed the EBTCM, not sure about the wheel speed sensor. Oh well, it's on there now and you can't send those parts back!!
Thanks for the help Bill!
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Intermediate
Joined: Jul 2003
Posts: 34
Likes: 0
From: Boynton Beach Florida
Help!! I have a few issues going on at the same time. I was receiving the 1214 code, so I have sent my part into the ABSfixer and am waiting for it to come back. I drove the car a little for two days, then on the third, I got in, inserted the key, and nothing, even though I had a good charge. I displayed codes, and among others, got the 2723 and 1040. I couldn't find what the 1040 was, but the 2723 was something to do with ignittion cylinder, so I replaced it yesterday. The car started up, I drove it about 10 miles, then came home. This morning, inserted the key, and nothing again The battery WAS dead, so I am going to take it in and have it checked. Please, any ideas that can keep out of the Chevrolet Service Department.
2nd Gear
Joined: Feb 2008
Posts: 2
Likes: 0
Electrical Connector issues & grounds
I have been a product engineer for Tyco Electronics for the past 24 years and we supply a large number of electronic connectors to the automotive ind. The issue of corroded grounds is common but just as common are corroded contacts of all types. I would venture a guess that as high as 90% of the electrical problems we have with our vettes are the result of contact/connector problems and not module failure. Bill Curlee described in his article dated 9/3/04 that when he moved the contacts ( grounds ) the problem went away and that is the way it works. The problem comes in that if you do not do anything to protect the mating contacts after cleaning the problem will return. The correct term for what is occuring is fretting corrosion and what must be done to stop fretting corrosion is to apply a grease to both the mating contacts. This will prevent oxygen from getting to the mating surface of the two contacts and forming an oxide. Be very careful at this point because only a grease designed for this purpose can be used, some greases could make the problem worse. There are several good greases on the market. The one I use is made by Nye Lubricants and is called Nyogel 760G. Unmate the connector, give the contacts a good cleaning, apply a liberal amount of the grease to both contacts and your problems should be greatly reduced.
2nd Gear
Joined: Feb 2008
Posts: 2
Likes: 0
Head light motor repair
Bill,
I have read your posts with great interest. I have a 2000 convertible that just came up with 2 issues on the same day. The Traction Control Failure message started appearing. This has happened randoml before. And also the headlight motor makes a grinding noise when lowering. This noise goes on for 3 or 4 seconds and turns off. I disconnected one lamp to see which was making the grinding and discovered both were doing it. What are the chances of both going out on the same day? Somewhre I read that there is a sensor that controls the lowering and raising of the headlights and that it is located under the passenger side houseing. I'm not too sure how to get to it and also how to test it. Thank you in advance for all your commenst and help.
Mark Bradford
Austin Texas
I have read your posts with great interest. I have a 2000 convertible that just came up with 2 issues on the same day. The Traction Control Failure message started appearing. This has happened randoml before. And also the headlight motor makes a grinding noise when lowering. This noise goes on for 3 or 4 seconds and turns off. I disconnected one lamp to see which was making the grinding and discovered both were doing it. What are the chances of both going out on the same day? Somewhre I read that there is a sensor that controls the lowering and raising of the headlights and that it is located under the passenger side houseing. I'm not too sure how to get to it and also how to test it. Thank you in advance for all your commenst and help.
Mark Bradford
Austin Texas
I recently had to rebuild my head light motor and I was very impressed with the rebuild kit I got from Top-Down Solutions. Their ph# is 626-369-0040. The kit was $45.00.
Don Crowe
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,396
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If your using a Navy Marine Corps Internet (NMCI) computer, it will NOT let you access U TUBE, PHOTOBUCKET, MYSPACE, ect......
All my photos are hosted on my photobucket account. If you access the forum from your home PC, they should bet viewable.
I cant see any some forum pictures at work on the SUBMARINE Base either. There are however some that I can see.
BC
All my photos are hosted on my photobucket account. If you access the forum from your home PC, they should bet viewable.
I cant see any some forum pictures at work on the SUBMARINE Base either. There are however some that I can see.
BC
Team Owner
Joined: Jun 1999
Posts: 30,492
Likes: 11
From: San Antonio Texas
Cruise-In IV Veteran
Cruise-In V Veteran
This thread has been very helpful so far, Thanks BC!. I have read most all of it now and I will be cleaning some of my ground connectors and battery terminals this weekend to see how many of my issues are cleared by that.
Here is the background on my C5's problems. My car has 104K+ miles on it ( yeah, it's been one solid daily driver for 8 yrs) A few months ago I would experience this problem. When hitting a bump or in some situations just making a corner my instrument panel would flash, exhibiting the exact same behavior as when you start the car, DIC would display "Corvette by Chevrolet" and the whole 9 yds. The car never shut off but it did get my attention. As this happened a few more times I began to think that I had a short in the ignition system.
This week a slew of new problems appeared that spurred me to do some research. First my passenger door lost all power. While messing with it in my driveway my car got hit with the "Reduced Engine Power" Service everything messages for the first time in it's life. I shut it all down, started it back up, car was ok but my door was still dead. Thinking it might be a blown fuse or something I checked the fuses for the door in the footwell panel, both were good, so I replaced them and it started working. I'm thinking now that I must have bumped the wiring harness for the door during this effort.
Then 4 times in the last 2 days I have got the "Reduced Engine Power" Service everything problems and my passenger door lost all power yet again.
Last night I pulled my codes and they are as follows (all history):
10 PCM - P1626
28 TCS - U1301, C1226, U1016
40 BCM - U1255, U1096, U1016
58 SDM - U1301, U1096
60 IPC - U1255, U1040, U1016, U1064, U1160, U1088, U1176
80 Radio - U1064, U1016, U1096
A0 LDCM - U1255, U1064, U1016, U1096
A1 RDCM - NO COMM
BO RFA - U1255, U1096, U1064, U1016
I cleared them all last night and when I got to work today I checked them again and nothing was tripped on my commute, but my passenger door is still dead. I realize that most are Failed Communication errors between modules but the ones I am most concerned with are P1626 and U1301.
I will be cleaning the easy to reach ground connectors tomorrow and see if I can check the wiring harness in the accordian tube on the passenger door to see what problems lie there.
Any advice, tips, experience anyone can share with these specific issues would be most helpful.
Here is the background on my C5's problems. My car has 104K+ miles on it ( yeah, it's been one solid daily driver for 8 yrs) A few months ago I would experience this problem. When hitting a bump or in some situations just making a corner my instrument panel would flash, exhibiting the exact same behavior as when you start the car, DIC would display "Corvette by Chevrolet" and the whole 9 yds. The car never shut off but it did get my attention. As this happened a few more times I began to think that I had a short in the ignition system.
This week a slew of new problems appeared that spurred me to do some research. First my passenger door lost all power. While messing with it in my driveway my car got hit with the "Reduced Engine Power" Service everything messages for the first time in it's life. I shut it all down, started it back up, car was ok but my door was still dead. Thinking it might be a blown fuse or something I checked the fuses for the door in the footwell panel, both were good, so I replaced them and it started working. I'm thinking now that I must have bumped the wiring harness for the door during this effort.
Then 4 times in the last 2 days I have got the "Reduced Engine Power" Service everything problems and my passenger door lost all power yet again.
Last night I pulled my codes and they are as follows (all history):
10 PCM - P1626
28 TCS - U1301, C1226, U1016
40 BCM - U1255, U1096, U1016
58 SDM - U1301, U1096
60 IPC - U1255, U1040, U1016, U1064, U1160, U1088, U1176
80 Radio - U1064, U1016, U1096
A0 LDCM - U1255, U1064, U1016, U1096
A1 RDCM - NO COMM
BO RFA - U1255, U1096, U1064, U1016
I cleared them all last night and when I got to work today I checked them again and nothing was tripped on my commute, but my passenger door is still dead. I realize that most are Failed Communication errors between modules but the ones I am most concerned with are P1626 and U1301.
I will be cleaning the easy to reach ground connectors tomorrow and see if I can check the wiring harness in the accordian tube on the passenger door to see what problems lie there.
Any advice, tips, experience anyone can share with these specific issues would be most helpful.
Le Mans Master
Joined: Dec 1999
Posts: 5,169
Likes: 6
From: Greenville SC
I hit a puddle on the right front side on my way to work. Nothing special, just one of those puddles that pulls the steering wheel a tiny bit and makes a lot of noise and startles you. I noticed something on the DIC and assumed it was ABS activating the way it does sometimes on puddles or railroad tracks or bumpy roads. It kept making a racket and I looked down and saw it said
SERVICE ABS, SERVICE AH, SERVICE TC
I've had that error before, and usually it goes away with the next start. It also usually is more likely to happen in cold weather. So I gave it a couple of days of sunny, warm (60-70 degree) days and no luck. Next, I came here and found this thread.
I pulled my codes and the only current code I had was the dreaded C1214 code. I had some door codes in history, which doesn't surprise me because my locks have been flaky as heck lately. But nothing that would pertain to this problem.
Next I went through my grounds with a fine tooth comb. They all looked good, except for some black paint on the studs, which I scraped off real good. Whoever decided to use TALL studs on those grounds in the engine compartment should be strung up. You can't easily get a wrench on them, and unless you have a SMALL SIZED (3/8 or 10mm) deep well socket kit (I don't) they are a bear. I also got my Voltmeter out and checked my connections and fuses as well as I could and I am pulling a solid 14 volts to all the grounds I could get to. I then loosened the connector to the EBCM and retightened it a couple of times with that big gray lever bar thing. I restarted the car and got the three error messages.
Oh well, it's time to pull the EBCM off and send it to the magic ABSFIXER guy. That turned out to be interesting.
I have a Z06. I think that means I have a power steering cooler that the standard C5 doesn't have. RIGHT WHERE your arm needs to be most of the time while working on the EBCM. My right arm is shredded. Looking back, I'd recommend long sleeve shirts for this removal.
I got the 6 torx screws off, with some contortions and running the car up on ramps. I am still wondering what it is going to be like to get them back ON...
Also I would note that the ABSFIXER site says to gently remove the module. They don't mention that some sort of LOCKTITE is used on the EBCM face. I ended up using an old wood chisel to get between the two surfaces and twist. The whole time I kept wondering if I was about to ruin my entire ABS. But it eventually popped off.
Getting it out of there was a challenge too. I went through the top. I bet the bottom would have been easier. So... that leaves me with the EBCM ready to go to ABSFIXER for the $150 special. If that works, I will be a happy camper.
One other side note, once you pull the EBCM, you get a lot fewer error codes. I just get a "SERVICE VEHICLE SOON" code now instead of three codes when I start up... so that is nice.
I'll post back and let you know if the ABSFIXER works. If it does I'll be
SERVICE ABS, SERVICE AH, SERVICE TC
I've had that error before, and usually it goes away with the next start. It also usually is more likely to happen in cold weather. So I gave it a couple of days of sunny, warm (60-70 degree) days and no luck. Next, I came here and found this thread.
I pulled my codes and the only current code I had was the dreaded C1214 code. I had some door codes in history, which doesn't surprise me because my locks have been flaky as heck lately. But nothing that would pertain to this problem.
Next I went through my grounds with a fine tooth comb. They all looked good, except for some black paint on the studs, which I scraped off real good. Whoever decided to use TALL studs on those grounds in the engine compartment should be strung up. You can't easily get a wrench on them, and unless you have a SMALL SIZED (3/8 or 10mm) deep well socket kit (I don't) they are a bear. I also got my Voltmeter out and checked my connections and fuses as well as I could and I am pulling a solid 14 volts to all the grounds I could get to. I then loosened the connector to the EBCM and retightened it a couple of times with that big gray lever bar thing. I restarted the car and got the three error messages.
Oh well, it's time to pull the EBCM off and send it to the magic ABSFIXER guy. That turned out to be interesting.
I have a Z06. I think that means I have a power steering cooler that the standard C5 doesn't have. RIGHT WHERE your arm needs to be most of the time while working on the EBCM. My right arm is shredded. Looking back, I'd recommend long sleeve shirts for this removal.
I got the 6 torx screws off, with some contortions and running the car up on ramps. I am still wondering what it is going to be like to get them back ON...
Also I would note that the ABSFIXER site says to gently remove the module. They don't mention that some sort of LOCKTITE is used on the EBCM face. I ended up using an old wood chisel to get between the two surfaces and twist. The whole time I kept wondering if I was about to ruin my entire ABS. But it eventually popped off.
Getting it out of there was a challenge too. I went through the top. I bet the bottom would have been easier. So... that leaves me with the EBCM ready to go to ABSFIXER for the $150 special. If that works, I will be a happy camper.
One other side note, once you pull the EBCM, you get a lot fewer error codes. I just get a "SERVICE VEHICLE SOON" code now instead of three codes when I start up... so that is nice.
I'll post back and let you know if the ABSFIXER works. If it does I'll be
Suprisingly it was a much easier install than removal. Maybe because I had figured out a lot of where I had room to move in there and because I wore long sleeves this time.
Started the car to pull it off the ramps and got:
SERVICE AH
SERVICE TC
No message about ABS though. I thought, "Well, one down - two to go - but he did fix the ABS."
Put up the ramps, went back out to the car to pull it in the garage and started it up and got no codes and my AH seems to cycle through the options correctly.
I pulled it in the garage and I'll report back when I drive it again (Monday at the latest, as this is my daily driver to work.) But for now, it appears that for $163 (inlcluding shipping) I am fixed.
ONE THING I'D LIKE TO ASK those of you who have sent the module in for repair. When I removed the module and drove the car, it immediately felt like the power steering assist had been greatly reduced. I even turned my key off at one point to compare and see if I was getting any power steering (I WAS, it was still much harder to drive with the car OFF).
When I pulled into the garage with the ABS FIXER rebuilt module on, my power steering was back to full. It was immediately noticable.
I haven't seen this mentioned by anyone else...
I'll report back next week to confirm that the fix has taken and is still working - but so far my hat is off to Brandon for saving me a bundle of cash.
Last edited by Tom Steele; Mar 1, 2008 at 04:05 PM. Reason: tightening up quotes
Instructor
Joined: Feb 2002
Posts: 219
Likes: 0
From: Daphne AL
Tcs C1288& C12887
Hi Bill,
I have an '03 ZO6 and usually right I after I start driving in the mornings, the first or second time I push the brake (lite pressure, equal to resting your foot on the pedal) it feels like the front brakes grabs for about a 1/10 of a second and I get the Active Handling Active message. When this happens I am usually not going over 20 mph and the road is smooth and fairly straight. But rarely does it does it throw codes from this. Also this never happens if I turn off A/H & T/C before leaving the driveway.
Then after a mile or two of driving I get the Service A/H Service T/C warnings and the yellow TCS OFF light. This also happens if I turn A/H & T/C off before ever leaving the driveway, and will always throw error codes. This normally happens when on a semi-bumpy highway.
The codes are always TCS C1288 & C1287. There is a BCM code but I dont remember what it is. I checked the ground points on the frame rails in the engine bay. (They had very very lite corrosion but I cleaned them using a Dremmel with a steel strip brush and sprayed CRC's electrical grade silicon lubricant on them.)
What would cause this? Is this a ground issue or a bad sensor issue??
BTW, where can I get a manual like the one in those pictures? and are they model specific (ZO6 vs Coupe) or fairly generalized?
I have an '03 ZO6 and usually right I after I start driving in the mornings, the first or second time I push the brake (lite pressure, equal to resting your foot on the pedal) it feels like the front brakes grabs for about a 1/10 of a second and I get the Active Handling Active message. When this happens I am usually not going over 20 mph and the road is smooth and fairly straight. But rarely does it does it throw codes from this. Also this never happens if I turn off A/H & T/C before leaving the driveway.
Then after a mile or two of driving I get the Service A/H Service T/C warnings and the yellow TCS OFF light. This also happens if I turn A/H & T/C off before ever leaving the driveway, and will always throw error codes. This normally happens when on a semi-bumpy highway.
The codes are always TCS C1288 & C1287. There is a BCM code but I dont remember what it is. I checked the ground points on the frame rails in the engine bay. (They had very very lite corrosion but I cleaned them using a Dremmel with a steel strip brush and sprayed CRC's electrical grade silicon lubricant on them.)
What would cause this? Is this a ground issue or a bad sensor issue??
BTW, where can I get a manual like the one in those pictures? and are they model specific (ZO6 vs Coupe) or fairly generalized?
Last edited by MongoosC5; Mar 5, 2008 at 02:48 PM.
Team Owner
Joined: Jun 1999
Posts: 30,492
Likes: 11
From: San Antonio Texas
Cruise-In IV Veteran
Cruise-In V Veteran
Update
This thread has been very helpful so far, Thanks BC!. I have read most all of it now and I will be cleaning some of my ground connectors and battery terminals this weekend to see how many of my issues are cleared by that.
Here is the background on my C5's problems. My car has 104K+ miles on it ( yeah, it's been one solid daily driver for 8 yrs) A few months ago I would experience this problem. When hitting a bump or in some situations just making a corner my instrument panel would flash, exhibiting the exact same behavior as when you start the car, DIC would display "Corvette by Chevrolet" and the whole 9 yds. The car never shut off but it did get my attention. As this happened a few more times I began to think that I had a short in the ignition system.
This week a slew of new problems appeared that spurred me to do some research. First my passenger door lost all power. While messing with it in my driveway my car got hit with the "Reduced Engine Power" Service everything messages for the first time in it's life. I shut it all down, started it back up, car was ok but my door was still dead. Thinking it might be a blown fuse or something I checked the fuses for the door in the footwell panel, both were good, so I replaced them and it started working. I'm thinking now that I must have bumped the wiring harness for the door during this effort.
Then 4 times in the last 2 days I have got the "Reduced Engine Power" Service everything problems and my passenger door lost all power yet again.
Last night I pulled my codes and they are as follows (all history):
10 PCM - P1626
28 TCS - U1301, C1226, U1016
40 BCM - U1255, U1096, U1016
58 SDM - U1301, U1096
60 IPC - U1255, U1040, U1016, U1064, U1160, U1088, U1176
80 Radio - U1064, U1016, U1096
A0 LDCM - U1255, U1064, U1016, U1096
A1 RDCM - NO COMM
BO RFA - U1255, U1096, U1064, U1016
I cleared them all last night and when I got to work today I checked them again and nothing was tripped on my commute, but my passenger door is still dead. I realize that most are Failed Communication errors between modules but the ones I am most concerned with are P1626 and U1301.
I will be cleaning the easy to reach ground connectors tomorrow and see if I can check the wiring harness in the accordian tube on the passenger door to see what problems lie there.
Any advice, tips, experience anyone can share with these specific issues would be most helpful.
Here is the background on my C5's problems. My car has 104K+ miles on it ( yeah, it's been one solid daily driver for 8 yrs) A few months ago I would experience this problem. When hitting a bump or in some situations just making a corner my instrument panel would flash, exhibiting the exact same behavior as when you start the car, DIC would display "Corvette by Chevrolet" and the whole 9 yds. The car never shut off but it did get my attention. As this happened a few more times I began to think that I had a short in the ignition system.
This week a slew of new problems appeared that spurred me to do some research. First my passenger door lost all power. While messing with it in my driveway my car got hit with the "Reduced Engine Power" Service everything messages for the first time in it's life. I shut it all down, started it back up, car was ok but my door was still dead. Thinking it might be a blown fuse or something I checked the fuses for the door in the footwell panel, both were good, so I replaced them and it started working. I'm thinking now that I must have bumped the wiring harness for the door during this effort.
Then 4 times in the last 2 days I have got the "Reduced Engine Power" Service everything problems and my passenger door lost all power yet again.
Last night I pulled my codes and they are as follows (all history):
10 PCM - P1626
28 TCS - U1301, C1226, U1016
40 BCM - U1255, U1096, U1016
58 SDM - U1301, U1096
60 IPC - U1255, U1040, U1016, U1064, U1160, U1088, U1176
80 Radio - U1064, U1016, U1096
A0 LDCM - U1255, U1064, U1016, U1096
A1 RDCM - NO COMM
BO RFA - U1255, U1096, U1064, U1016
I cleared them all last night and when I got to work today I checked them again and nothing was tripped on my commute, but my passenger door is still dead. I realize that most are Failed Communication errors between modules but the ones I am most concerned with are P1626 and U1301.
I will be cleaning the easy to reach ground connectors tomorrow and see if I can check the wiring harness in the accordian tube on the passenger door to see what problems lie there.
Any advice, tips, experience anyone can share with these specific issues would be most helpful.
Well I "tried" to clean my ground connectors but I guess after 8 yrs they are determined to not come apart. I tried valantly on the 2 grounds in the engine bay to no avail. I could get them unscrewed from the frame just fine, but after much effort with a screw driver to pry the connector apart, no can do, those tabs just are hard as a rock, no budging at all. So if this truly is a problem for me I'm not sure how I will be able to correct it myself.
As for my door, I pulled back the accordian tube to expose the wires some and I wiggled them around quite a bit and power came back, but I don't see how I can reach any connections at either end without stripping our door panels and such. After I got power back to the door I pulled codes again and my passenger door gave me two codes:
B2285
U1064
Unlike some guys here I"m not super mechanically inclined nor can I afford to tear my car down and not have it usable the following day for going to work if I screw something up.
Any help??
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,396
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Update on my problems.
Well I "tried" to clean my ground connectors but I guess after 8 yrs they are determined to not come apart. I tried valantly on the 2 grounds in the engine bay to no avail. I could get them unscrewed from the frame just fine, but after much effort with a screw driver to pry the connector apart, no can do, those tabs just are hard as a rock, no budging at all. So if this truly is a problem for me I'm not sure how I will be able to correct it myself.
As for my door, I pulled back the accordian tube to expose the wires some and I wiggled them around quite a bit and power came back, but I don't see how I can reach any connections at either end without stripping our door panels and such. After I got power back to the door I pulled codes again and my passenger door gave me two codes:
B2285
U1064
Unlike some guys here I"m not super mechanically inclined nor can I afford to tear my car down and not have it usable the following day for going to work if I screw something up.
Any help??
Well I "tried" to clean my ground connectors but I guess after 8 yrs they are determined to not come apart. I tried valantly on the 2 grounds in the engine bay to no avail. I could get them unscrewed from the frame just fine, but after much effort with a screw driver to pry the connector apart, no can do, those tabs just are hard as a rock, no budging at all. So if this truly is a problem for me I'm not sure how I will be able to correct it myself.
As for my door, I pulled back the accordian tube to expose the wires some and I wiggled them around quite a bit and power came back, but I don't see how I can reach any connections at either end without stripping our door panels and such. After I got power back to the door I pulled codes again and my passenger door gave me two codes:
B2285
U1064
Unlike some guys here I"m not super mechanically inclined nor can I afford to tear my car down and not have it usable the following day for going to work if I screw something up.
Any help??
There are TWO small plastic retainers (one on each side) that need to be released using a small screw driver. While prying on the plastic loops to release clips,,,,pull and wiggle the ground lug.
If its that tight, its probably corroded in place. There designed to be tight but NOT so tight that they wont separate.
As for the door wiring harnesses, there should be ample harness to do all the cleaning you need to do. the extra wire and connectors will be tucked inside the door frame area. Pop both ends of the accordion tube loose and it will make life simple:
Once you get the connector in the open, separate it and look for corroded pins, loose connections or bare wires.
This is doable, you just need to give it a chance.
BC
BC