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
G-103 Is on top of the frame rail directly below the brake master cylinder. YES there is a braded wire connected to it that goes over to the drivers side of the engine on the block. The same exact type of connection as is on the passengers side of the engine for the battery negative wire.
Heel & Toe
Joined: Nov 2014
Posts: 24
Likes: 1
From: Cherry Hill NJ
G-103 Is on top of the frame rail directly below the brake master cylinder. YES there is a braded wire connected to it that goes over to the drivers side of the engine on the block. The same exact type of connection as is on the passengers side of the engine for the battery negative wire.
2nd Gear
Joined: Apr 2018
Posts: 2
Likes: 0
Thank you for info.. I am a new up-coming owner. The car I am going to buy, 2001 6sp Manual. the current owner read about this fix and has cleaned the grounding points which solved the "traction" stabilization code dash light issues.
The only other electrical issues have been an ignition switch which was replaced.. and headlights which were replaced early on under warranty. The steering wheel lock was also fixed.
More recently Last year a turn signals issue was fixed by replacing Hazard flasher inside dash.. but NOW the brake lights are not working. (Except the center brake light works) could this be the hazard flasher again? Is this common to go through 2 replacements of the flasher under 5k miles?
OR could it be related to a ground point on the chassis ?
One more question.. Could the above 5 issues be considered a "caution flag" to purchase this particular car?
In other words, could this particular car be prone to a LOT of "electrical issues" in the future?
OR would this be normal electrical issues for a 17 year old car (2001) ?
Thanks in advance for any advice.
The only other electrical issues have been an ignition switch which was replaced.. and headlights which were replaced early on under warranty. The steering wheel lock was also fixed.
More recently Last year a turn signals issue was fixed by replacing Hazard flasher inside dash.. but NOW the brake lights are not working. (Except the center brake light works) could this be the hazard flasher again? Is this common to go through 2 replacements of the flasher under 5k miles?
OR could it be related to a ground point on the chassis ?
One more question.. Could the above 5 issues be considered a "caution flag" to purchase this particular car?
In other words, could this particular car be prone to a LOT of "electrical issues" in the future?
OR would this be normal electrical issues for a 17 year old car (2001) ?
Thanks in advance for any advice.
Last edited by Temblor; Apr 27, 2018 at 03:26 PM.
Instructor
Joined: Jul 2015
Posts: 127
Likes: 8
From: Cream Ridge NJ
Hmmmmm.....
I had to replace my blinker/hazard relay above the radio. I did it because my blinkers would stop working and to make them work I would have to slap the dash until one day the love tap didn't work anymore. My first thought when u mention brake lights not working I thought simple probably the switch above the brake pedal, but u said the center brake light works? Weird, there's some guys on here that really know there stuff, I've been a learn as I go guy with this particular car. I have to be honest, I HATE and I can't stress that word enough when it comes to electrical problems. Tracing electrical problems for me is like putting together a 1000 piece puzzle and nobody told me pieces are missing. Grrrrrrrr...... Again there are some really knowledgeable guys on here, this may be simple? Or they may tell u to run to the hills.... There's a guy on here that has answered many questions I've asked on here I believe his name is Bill Curlee, he is like the corvette God. If that dude doesn't have an answer, I'd probably walk away. Make sure the car has never been hit or had water damage. That's my number one rule personally, I never buy a car that's been in a accident or salvage title, I believe it's taboo. I'm weird like that. A guy at the corvette salvage yard told me if a vettes air bags ever went off, the vette is ready for the junkyard. I have to say I really love my vette, but I wish it was as trouble free as my toyota's. I have 3 in my household and in about 3 years I've owned my vette, I've wrenched on my vette more than all 3 toyota's put together and my vette gets royalty treatment it even gets stored in a carport canopy with a cover too with repels-all sprinkled around and underneath to keep the critters away!!! Stupid BS problems seem to be an added bonus with some of these cars? Lol...... If your handy and don't mind some wrenching it's a cool car, but if u have to put this car in the shop for every problem u will go broke..... Good luck, keep us updated.
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
Thank you for info.. I am a new up-coming owner. The car I am going to buy, 2001 6sp Manual. the current owner read about this fix and has cleaned the grounding points which solved the "traction" stabilization code dash light issues.
The only other electrical issues have been an ignition switch which was replaced.. and headlights which were replaced early on under warranty. The steering wheel lock was also fixed.
More recently Last year a turn signals issue was fixed by replacing Hazard flasher inside dash.. but NOW the brake lights are not working. (Except the center brake light works) could this be the hazard flasher again? Is this common to go through 2 replacements of the flasher under 5k miles?
OR could it be related to a ground point on the chassis ?
One more question.. Could the above 5 issues be considered a "caution flag" to purchase this particular car?
In other words, could this particular car be prone to a LOT of "electrical issues" in the future?
OR would this be normal electrical issues for a 17 year old car (2001) ?
Thanks in advance for any advice.
The only other electrical issues have been an ignition switch which was replaced.. and headlights which were replaced early on under warranty. The steering wheel lock was also fixed.
More recently Last year a turn signals issue was fixed by replacing Hazard flasher inside dash.. but NOW the brake lights are not working. (Except the center brake light works) could this be the hazard flasher again? Is this common to go through 2 replacements of the flasher under 5k miles?
OR could it be related to a ground point on the chassis ?
One more question.. Could the above 5 issues be considered a "caution flag" to purchase this particular car?
In other words, could this particular car be prone to a LOT of "electrical issues" in the future?
OR would this be normal electrical issues for a 17 year old car (2001) ?
Thanks in advance for any advice.
As James stated, if the car has not had any MAJOR problems, and drives well and has been taken care of, PURCHASE IT!
Bill
2nd Gear
Joined: Apr 2018
Posts: 2
Likes: 0
I had to replace my blinker/hazard relay above the radio. I did it because my blinkers would stop working and to make them work I would have to slap the dash until one day the love tap didn't work anymore. My first thought when u mention brake lights not working I thought simple probably the switch above the brake pedal, but u said the center brake light works? Weird, there's some guys on here that really know there stuff, I've been a learn as I go guy with this particular car. I have to be honest, I HATE and I can't stress that word enough when it comes to electrical problems. Tracing electrical problems for me is like putting together a 1000 piece puzzle and nobody told me pieces are missing. Grrrrrrrr...... Again there are some really knowledgeable guys on here, this may be simple? Or they may tell u to run to the hills.... There's a guy on here that has answered many questions I've asked on here I believe his name is Bill Curlee, he is like the corvette God. If that dude doesn't have an answer, I'd probably walk away. Make sure the car has never been hit or had water damage. That's my number one rule personally, I never buy a car that's been in a accident or salvage title, I believe it's taboo. I'm weird like that. A guy at the corvette salvage yard told me if a vettes air bags ever went off, the vette is ready for the junkyard. I have to say I really love my vette, but I wish it was as trouble free as my Toyota's. I have 3 in my household and in about 3 years I've owned my vette, I've wrenched on my vette more than all 3 Toyota's put together and my vette gets royalty treatment it even gets stored in a carport canopy with a cover too with repels-all sprinkled around and underneath to keep the critters away!!! Stupid BS problems seem to be an added bonus with some of these cars? Lol...... If your handy and don't mind some wrenching it's a cool car, but if u have to put this car in the shop for every problem u will go broke..... Good luck, keep us updated.
Regarding electronics I always buy appliances with manual controls.. NEVER the fancy digital read out computer boards.. designed to fail and expensive.. Gibson front load washers last a lifetime.. but occasionally need a sensor or switch.. speaking of electronics I have a 1971 Ford F350 / dump.. with an inline 6 (300) and this truck is EMP proof? it has always started every time.. a little loose driving that truck but it is a gem..
Having said that the owner of the Vette is a good guy.. fixed the issue.. it was the Hazard sensor in the dash.. So I am going to pick it up! Beautiful 55K 6sp vert..no dash warning lights now.. always garaged.. and this forum has given me confidence I can trouble shoot and fix any future issues.. my first Vette.. and near my Birthday
My plan is to drive this for a couple years then maybe upgrade to a C6.. LS3.. which is out of my budget right now..Thanks for any insights and future comments..hope my post helps someone too..
Have to Pay to play..in a Vette.. Will be talkin again soon I am sure..
Last edited by Temblor; Apr 28, 2018 at 01:30 PM.
Instructor
Joined: Jul 2015
Posts: 127
Likes: 8
From: Cream Ridge NJ
Traction control??? I had a similar issue I believe that would come on with the ABS light? I researched it. I checked all my grounds and all where good and clean. I like to put dialectode grease on everything so I added that to a lot of my contacts. I also read somewhere else that a lot of corvettes never see weather bad enough to engage the ABS and that some times the ABS unit either seizes or sticks from lack of use. So what I did and still do once in a while before I do a washing. I find some grassy shoulder on the back roads and pull off the road and repeatedly apply the brakes and make the ABS engage and haven't had the light come on in well over a year maybe 2. Now that I've said that, I'm sure the light will come on now? Lol.... One little bit of advice from my experience, if u get a vette, drive the F'ing thing! Almost everyone I talk to that has a garage queen (even in climate controlled garages) seems to have way more problems/issues than people who actually drive it. Like that old saying, a body in motion, stays in motion.....
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Burning Brakes
Joined: Nov 2006
Posts: 768
Likes: 25
From: Cape Cod
reduce engine speed
Quote:
Originally Posted by leo12
Hey bill,great write up on the c5 notorious electrical problems, Need a bit help here,just last summer I noticed that every time I turn the traction control off my c5 the car at times will go into limp mode, REDUCE ENGIE POWER....TRACTION CONTROL FAILURE,in the beginning it wasn't too bad, I would just shut it off wait a couple seconds and off I go,late in the summer it progressively got so bad that every time I turned the traction control of it would go into limp mode and stay there to the point that I couldn't start it back up a gain for a hour or soo,now I'm at the point that I can't take the traction control off and that's no fun.anything more I should be looking at said the grounds?.
Lets start with a good fresh DTC read using the IPC DIC.
Erase/clear "ALL" the old DTCs. Then take the car for a drive and make it fail.
When it fails, press RESET/ CLEAR to get rid of all the messages/warnings. When there all gone, read and post ALL the DTCs "BEFORE" you turn the ignition off.
Make sure that you include all the prefixis and H/Cs
With that data, we can get to troubleshooting.
Bill
Hey Guys
Its ben a little while sense i was able to get back on the Vette,so heres the story after i got the car ready for the summer,A couple weeks ago i drove it a few times with no problems.
Two days ago i started the car and the car engine lite went on and flashing reduce engine speed,the traction control went off,by it self and service traction control was flashing and it went into limp mode.i pulled the codes and here they are.All the engine grounds and traction control ground have ben addressed and are in proper working order.
I would like to hear any recommendation,fixes that will allow me to enjoy this Damnnn Vette again .
Thanks for all the help.
P0102 = Mass air flow sensor,H(Note )There no Mass in the car,Speed density tuned.
P1220 =TP sensor 2. H-C
P1221=TPsensor ,1,2 performance H-C.
U1016=Loss of comm with PCM , H
U1064 = Loss of comm with BCM both H.
U1096 = Loss of comm with IPC , H
C1278 =TCS temporary inhibited by BCM, H-C (Note) when i reset this code that is when the engine lite and reduce engine speed goes off
C1281= Steering sensor,H (Note) the steering lock has be disabled/bypassed for 7 years now
Originally Posted by leo12
Hey bill,great write up on the c5 notorious electrical problems, Need a bit help here,just last summer I noticed that every time I turn the traction control off my c5 the car at times will go into limp mode, REDUCE ENGIE POWER....TRACTION CONTROL FAILURE,in the beginning it wasn't too bad, I would just shut it off wait a couple seconds and off I go,late in the summer it progressively got so bad that every time I turned the traction control of it would go into limp mode and stay there to the point that I couldn't start it back up a gain for a hour or soo,now I'm at the point that I can't take the traction control off and that's no fun.anything more I should be looking at said the grounds?.
Lets start with a good fresh DTC read using the IPC DIC.
Erase/clear "ALL" the old DTCs. Then take the car for a drive and make it fail.
When it fails, press RESET/ CLEAR to get rid of all the messages/warnings. When there all gone, read and post ALL the DTCs "BEFORE" you turn the ignition off.
Make sure that you include all the prefixis and H/Cs
With that data, we can get to troubleshooting.
Bill
Hey Guys
Its ben a little while sense i was able to get back on the Vette,so heres the story after i got the car ready for the summer,A couple weeks ago i drove it a few times with no problems.
Two days ago i started the car and the car engine lite went on and flashing reduce engine speed,the traction control went off,by it self and service traction control was flashing and it went into limp mode.i pulled the codes and here they are.All the engine grounds and traction control ground have ben addressed and are in proper working order.
I would like to hear any recommendation,fixes that will allow me to enjoy this Damnnn Vette again .
Thanks for all the help.
P0102 = Mass air flow sensor,H(Note )There no Mass in the car,Speed density tuned.
P1220 =TP sensor 2. H-C
P1221=TPsensor ,1,2 performance H-C.
U1016=Loss of comm with PCM , H
U1064 = Loss of comm with BCM both H.
U1096 = Loss of comm with IPC , H
C1278 =TCS temporary inhibited by BCM, H-C (Note) when i reset this code that is when the engine lite and reduce engine speed goes off
C1281= Steering sensor,H (Note) the steering lock has be disabled/bypassed for 7 years now
Last edited by leo12; Jun 24, 2018 at 07:12 PM. Reason: spelling
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
Quote:
Originally Posted by leo12
Hey bill,great write up on the c5 notorious electrical problems, Need a bit help here,just last summer I noticed that every time I turn the traction control off my c5 the car at times will go into limp mode, REDUCE ENGIE POWER....TRACTION CONTROL FAILURE,in the beginning it wasn't too bad, I would just shut it off wait a couple seconds and off I go,late in the summer it progressively got so bad that every time I turned the traction control of it would go into limp mode and stay there to the point that I couldn't start it back up a gain for a hour or soo,now I'm at the point that I can't take the traction control off and that's no fun.anything more I should be looking at said the grounds?.
Lets start with a good fresh DTC read using the IPC DIC.
Erase/clear "ALL" the old DTCs. Then take the car for a drive and make it fail.
When it fails, press RESET/ CLEAR to get rid of all the messages/warnings. When there all gone, read and post ALL the DTCs "BEFORE" you turn the ignition off.
Make sure that you include all the prefixis and H/Cs
With that data, we can get to troubleshooting.
Bill
Hey Guys
Its ben a little while sense i was able to get back on the Vette,so heres the story after i got the car ready for the summer,A couple weeks ago i drove it a few times with no problems.
Two days ago i started the car and the car engine lite went on and flashing reduce engine speed,the traction control went off,by it self and service traction control was flashing and it went into limp mode.i pulled the codes and here they are.All the engine grounds and traction control ground have ben addressed and are in proper working order.
I would like to hear any recommendation,fixes that will allow me to enjoy this Damnnn Vette again .
Thanks for all the help.
P0102 = Mass air flow sensor,H(Note )There no Mass in the car,Speed density tuned.
P1220 =TP sensor 2. H-C
P1221=TPsensor ,1,2 performance H-C.
U1016=Loss of comm with PCM , H
U1064 = Loss of comm with BCM both H.
U1096 = Loss of comm with IPC , H
C1278 =TCS temporary inhibited by BCM, H-C (Note) when i reset this code that is when the engine lite and reduce engine speed goes off
C1281= Steering sensor,H (Note) the steering lock has be disabled/bypassed for 7 years now
Originally Posted by leo12
Hey bill,great write up on the c5 notorious electrical problems, Need a bit help here,just last summer I noticed that every time I turn the traction control off my c5 the car at times will go into limp mode, REDUCE ENGIE POWER....TRACTION CONTROL FAILURE,in the beginning it wasn't too bad, I would just shut it off wait a couple seconds and off I go,late in the summer it progressively got so bad that every time I turned the traction control of it would go into limp mode and stay there to the point that I couldn't start it back up a gain for a hour or soo,now I'm at the point that I can't take the traction control off and that's no fun.anything more I should be looking at said the grounds?.
Lets start with a good fresh DTC read using the IPC DIC.
Erase/clear "ALL" the old DTCs. Then take the car for a drive and make it fail.
When it fails, press RESET/ CLEAR to get rid of all the messages/warnings. When there all gone, read and post ALL the DTCs "BEFORE" you turn the ignition off.
Make sure that you include all the prefixis and H/Cs
With that data, we can get to troubleshooting.
Bill
Hey Guys
Its ben a little while sense i was able to get back on the Vette,so heres the story after i got the car ready for the summer,A couple weeks ago i drove it a few times with no problems.
Two days ago i started the car and the car engine lite went on and flashing reduce engine speed,the traction control went off,by it self and service traction control was flashing and it went into limp mode.i pulled the codes and here they are.All the engine grounds and traction control ground have ben addressed and are in proper working order.
I would like to hear any recommendation,fixes that will allow me to enjoy this Damnnn Vette again .
Thanks for all the help.
P0102 = Mass air flow sensor,H(Note )There no Mass in the car,Speed density tuned.
P1220 =TP sensor 2. H-C
P1221=TPsensor ,1,2 performance H-C.
U1016=Loss of comm with PCM , H
U1064 = Loss of comm with BCM both H.
U1096 = Loss of comm with IPC , H
C1278 =TCS temporary inhibited by BCM, H-C (Note) when i reset this code that is when the engine lite and reduce engine speed goes off
C1281= Steering sensor,H (Note) the steering lock has be disabled/bypassed for 7 years now
If the voltage is good, you need to examine the serial data buss and see if there is something corrupting it.
Are you having any really weird gage readings in the IPC?
Make sure that the battery is fully charged and you are getting full charging voltage.
Bill
Burning Brakes
Joined: Nov 2006
Posts: 768
Likes: 25
From: Cape Cod
With all the LOSS OF COMMS, it sounds like you are having a voltage issue,,,, Each module has two power supplies. One from the battery and one from the IGNITION SWITCH. You need to find the fuses that are ignition switch powered and see if you have full BATTERY VOLTAGE on the test points on top of each fuse. Read the test points to chassis ground.
If the voltage is good, you need to examine the serial data buss and see if there is something corrupting it.
Are you having any really weird gage readings in the IPC?
Make sure that the battery is fully charged and you are getting full charging voltage.
Bill
If the voltage is good, you need to examine the serial data buss and see if there is something corrupting it.
Are you having any really weird gage readings in the IPC?
Make sure that the battery is fully charged and you are getting full charging voltage.
Bill
Man ,i can tear down engines,supercharge or turbo charge them but when it comes to electrical there's Nothing worse for me
Racer
Joined: Jul 2002
Posts: 476
Likes: 143
From: MS
Problem with Cooling Fans Operation
While on the Hot Rod Power Tour (HRPT) earlier this month, I was on the first leg in Bowling Green headed to Beech Bend Raceway and noticed my water temps were going up even with the A/C on recirculate. I found a place to pull over at the Raceway, opened the hood and verified that the high speed fan was not on. I pulled the underhood fuse box cover and found there were 3 relays (43-45), 2 maxifuses (46 & 49) and one minifuse (14) that were part of the cooling fans operation. With the help of Bill Curlee and another HRPT participant, who loaned me a multimeter, and after much probing and circuit testing, we (mostly Bill) determined that the #44 relay needed to be replaced. Being 15 miles from town with 7,000 participants and bumper to bumper traffic both ways for that 15 miles, I wasn’t wanting to ask someone to take me that 30 mile round trip to a parts store and wasn’t looking forward to limping back to town later on after the crowd had thinned out, without the high speed fan working. While watching the events and letting the car cool down, I happened to think of the Chevrolet Performance Motor Medics that help participants with various issues along the Power Tour. I found them at the end of the track and I guess worried them enough that they looked back in their stash and found the correct relay. Later in the day, after the crowd thinned, I bummed a ride back to my car, replaced the relay and everything was back to normal. Once again Bill Curlee pulled my bacon out of the fire, as he has for many members of this forum. Bless you Bill Curlee!
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
While on the Hot Rod Power Tour (HRPT) earlier this month, I was on the first leg in Bowling Green headed to Beech Bend Raceway and noticed my water temps were going up even with the A/C on recirculate. I found a place to pull over at the Raceway, opened the hood and verified that the high speed fan was not on. I pulled the underhood fuse box cover and found there were 3 relays (43-45), 2 maxifuses (46 & 49) and one minifuse (14) that were part of the cooling fans operation. With the help of Bill Curlee and another HRPT participant, who loaned me a multimeter, and after much probing and circuit testing, we (mostly Bill) determined that the #44 relay needed to be replaced. Being 15 miles from town with 7,000 participants and bumper to bumper traffic both ways for that 15 miles, I wasn’t wanting to ask someone to take me that 30 mile round trip to a parts store and wasn’t looking forward to limping back to town later on after the crowd had thinned out, without the high speed fan working. While watching the events and letting the car cool down, I happened to think of the Chevrolet Performance Motor Medics that help participants with various issues along the Power Tour. I found them at the end of the track and I guess worried them enough that they looked back in their stash and found the correct relay. Later in the day, after the crowd thinned, I bummed a ride back to my car, replaced the relay and everything was back to normal. Once again Bill Curlee pulled my bacon out of the fire, as he has for many members of this forum. Bless you Bill Curlee!
GLAD I was able to help ya!!. Anytime brother..Bill
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
NO nothing weird gage reading,the battery is new and fully charged,all the fuses seam in good working order,i did think it was a ignition switch problem a while back,i changed the switch but didn't fix the problem.
Man ,i can tear down engines,supercharge or turbo charge them but when it comes to electrical there's Nothing worse for me
Man ,i can tear down engines,supercharge or turbo charge them but when it comes to electrical there's Nothing worse for me
Bill
Last edited by Bill Curlee; Jun 27, 2018 at 07:05 PM.
Instructor
Joined: Aug 2003
Posts: 161
Likes: 0
From: Tacoma WA.
Many of you have asked me for help on solving electrical problems and I thought this would be VERY interesting!
My 98 coupe would get the infamous "REDUCED ENGINE POWER", "TRACTION CONTROL FAILURE" and a host of random failure codes. After many, many hours of troubleshooting, replacing the BCM and TAC module, I solved most of the driveability issues. Still getting the random DTC failure codes, I thought that I may be having ground issues. Back in June I cleaned ALL of the chassis grounds and the car virtually stopped throwing the "RANDOM" DTC failure codes. Just moving the wires in the chassis ground connector was enough to change the indications and make the issues stop happening.
I had a chance to speak with some GM C5 Trouble Desk Engineers when I went to Bowling Green KY in April and they pointed out that MANY of the C5 electrical issues can be directly linked to chassis ground problems. The engineer even went as far as to recommending that I chop off the factory under hood chassis ground connectors and combine all of the wires into a single ground lug. Not wanting to just LOP off the factory connector, I took a chance and disassembled one of the ground plug connectors and to my surprise it was indeed full of corroded connections.
I strongly recommend that any C5 owner that has had or who are having electrical issues, examine and clean the chassis ground connectors. This may save you from needlessly replacing expensive electronics modules. Each ground connector can be disassembled and cleaned in about 20 min.
Just cleaning the metal ground connection between the chassis and the plug is only a band aid solution. Now that I look back, when I cleaned my chassis grounds and initially solved my issues, I believe that when the connector is being removed to clean the connection between chassis and the connector, just the wires being moved inside the plug is what changed the indications and made everything work better.
Disassembly of the chassis ground plug and cleaning the contacts inside the connector is the correct method of solving the issue!
I took some pictures of the under hood chassis ground connector and the corrosion that was in it. I cleaned the two connections on the frame rails and the left one was significantly corroded! Taking it apart and cleaning it is a very straight forward procedure and I believe that if you follow this recommendation, you will be on the way to solving the many of the electrical issues.
Here are some detailed pictures of the ground connector and the corrosion that was found inside it!
Picture of under hood Chassis Ground connector G-101
Corrosion inside connector! (You ain't seen nothing yet!)
[IMG]
Next three photos are of the corrosion found on the connector terminals!
[IMG]
[IMG]
[IMG]
Self tapping ground screw and star washer. This is what you will need if the ground stud breaks off during removal!
[IMG]
[IMG][IMG]
Here are where the chassis ground points are on a C5:
Attachment 48174127
Attachment 48174128
PLEASE let me know if you have any questions. NOTE! All of the pictures that I have of C5 Grounds have been posted on or in this post.
Bill Curlee
updated 02 March 06
My 98 coupe would get the infamous "REDUCED ENGINE POWER", "TRACTION CONTROL FAILURE" and a host of random failure codes. After many, many hours of troubleshooting, replacing the BCM and TAC module, I solved most of the driveability issues. Still getting the random DTC failure codes, I thought that I may be having ground issues. Back in June I cleaned ALL of the chassis grounds and the car virtually stopped throwing the "RANDOM" DTC failure codes. Just moving the wires in the chassis ground connector was enough to change the indications and make the issues stop happening.
I had a chance to speak with some GM C5 Trouble Desk Engineers when I went to Bowling Green KY in April and they pointed out that MANY of the C5 electrical issues can be directly linked to chassis ground problems. The engineer even went as far as to recommending that I chop off the factory under hood chassis ground connectors and combine all of the wires into a single ground lug. Not wanting to just LOP off the factory connector, I took a chance and disassembled one of the ground plug connectors and to my surprise it was indeed full of corroded connections.
I strongly recommend that any C5 owner that has had or who are having electrical issues, examine and clean the chassis ground connectors. This may save you from needlessly replacing expensive electronics modules. Each ground connector can be disassembled and cleaned in about 20 min.
Just cleaning the metal ground connection between the chassis and the plug is only a band aid solution. Now that I look back, when I cleaned my chassis grounds and initially solved my issues, I believe that when the connector is being removed to clean the connection between chassis and the connector, just the wires being moved inside the plug is what changed the indications and made everything work better.
Disassembly of the chassis ground plug and cleaning the contacts inside the connector is the correct method of solving the issue!
I took some pictures of the under hood chassis ground connector and the corrosion that was in it. I cleaned the two connections on the frame rails and the left one was significantly corroded! Taking it apart and cleaning it is a very straight forward procedure and I believe that if you follow this recommendation, you will be on the way to solving the many of the electrical issues.
Here are some detailed pictures of the ground connector and the corrosion that was found inside it!
Picture of under hood Chassis Ground connector G-101
Corrosion inside connector! (You ain't seen nothing yet!)
[IMG]
Next three photos are of the corrosion found on the connector terminals!
[IMG]
[IMG] [IMG]Self tapping ground screw and star washer. This is what you will need if the ground stud breaks off during removal!
[IMG]
[IMG][IMG]Here are where the chassis ground points are on a C5:
Attachment 48174127
Attachment 48174128
PLEASE let me know if you have any questions. NOTE! All of the pictures that I have of C5 Grounds have been posted on or in this post.
Bill Curlee
updated 02 March 06
I've been fighting this problem for 6months (waiting for it to go away) I suspected a common bad ground but didn't know where to start. Thank you so much for sharing, I've cleaned the 4 grounds in the engine compartment and problem solved, test drove it over many potholes and nothing happened, no warning lights......WOW ! Life is whole again. thanks again
Burning Brakes
Joined: Nov 2006
Posts: 768
Likes: 25
From: Cape Cod
Racer
Joined: Jan 2018
Posts: 249
Likes: 49
From: Westcliffe CO
Another electrical problem tip, which the manual does NOT address...
The manual says (in two places) to adjust the dash lights from low to bright by turning the dash light control **** all the way to the right/clockwise to have the brightest dash lights. It says nothing about a click/indent at the end of that full turn on the ****. Turning full clockwise turns on your floor lights and map lights and since they are on, the BCM thinks the DCMs (door control modules) also need power because the BCM thinks the doors are open which also turns those lights on.
So when adjusting the dash lights, never turn and leave your dash light control **** turned past the click/indent, or all the way clockwise - to the right.
Go full right and stop turning before hitting the click/indent so that the map and floor lights are not left on when you park the car.
That will drain a battery pretty quick.
Don't ask me why I know!
The manual says (in two places) to adjust the dash lights from low to bright by turning the dash light control **** all the way to the right/clockwise to have the brightest dash lights. It says nothing about a click/indent at the end of that full turn on the ****. Turning full clockwise turns on your floor lights and map lights and since they are on, the BCM thinks the DCMs (door control modules) also need power because the BCM thinks the doors are open which also turns those lights on.
So when adjusting the dash lights, never turn and leave your dash light control **** turned past the click/indent, or all the way clockwise - to the right.
Go full right and stop turning before hitting the click/indent so that the map and floor lights are not left on when you park the car.
That will drain a battery pretty quick.
Don't ask me why I know!
Intermediate
Joined: Aug 2011
Posts: 25
Likes: 0
Pro
Joined: Jun 2007
Posts: 632
Likes: 6
From: St. Louis Missouri
Hi Bill, any suggestions what to look at for a "Service Vehicle Soon" light? I don't get any codes. I have a 2001 Convertible. I have tried pulling codes from the DIC, also after clearing them out, also with the engine still running after the message pops up and with HP Tuner. I do not get anything of interest.
Any thoughts would give me something to chase down.
-Rick
Any thoughts would give me something to chase down.
-Rick