IMPORTANT ELECTRICAL INFORMATION (Long!)
Advanced
Joined: Dec 2015
Posts: 83
Likes: 10
From: Oro Valley Arizona
7th Gear
Joined: Oct 2013
Posts: 7
Likes: 0
From: Waite Park MN
Just wanted to make a note here - I don't get on the forum as much as I would like (2 grandkids 8 & 22 months full time) but when I get a gremlin it always seems to be addressed here - this electrical post has saved me a ton. Bith my fog lamps died over the winter storage - after a little reading here I took a look at the ground on the left chassis - what a mess - guessing that is the issue.
I also had the fuel gage to zero gremlin - several mechanics said just change it out......2 cans of techtron - issue solved
Thanks guys - you make owning this car even more enjoyable
I also had the fuel gage to zero gremlin - several mechanics said just change it out......2 cans of techtron - issue solved
Thanks guys - you make owning this car even more enjoyable
Instructor
Joined: Mar 2016
Posts: 113
Likes: 4
From: Titusville Florida
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]
[/IMG]
Next three photos are of the corrosion found on the connector terminals!
[IMG]
[/IMG] [IMG]
[/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][IMG]
Here are where the chassis ground points are on a C5:
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]
[/IMG] Next three photos are of the corrosion found on the connector terminals!
[IMG]
[/IMG] [IMG][/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][IMG]Here are where the chassis ground points are on a C5:
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
BTW you wouldn't happen to have the part numbers for both the make and female connectors, and where they can be had, would you? :-)
Last edited by NavyGunner1980; May 23, 2016 at 08:18 PM.
Heel & Toe
Joined: Mar 2013
Posts: 19
Likes: 0
From: Akron ohio
same thing happened to my 03 so i took it to the dealer and after 1200$ and replacing a lot of pins and wires in the fuse box area of passenger side it was fix but i check the grounds I could see and I see corrosion in the pins and and black box and when I tried to carefully pull the wires for the box it would come out is there a special way of taking the wires and box off that iim doing wrong ?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
7 Bolt-On Upgrades From Extreme Online Store to Level Up Your C6 Corvette
Pouria Savadkouei
How Likely Are These Five 2027 Corvette Rumors to Be True?
Brett Foote
9 Best Corvettes You Can Buy for Half Price (& 1 You Should NEVER Buy!)
Joe Kucinski
8 Very Best Corvettes of Amelia Island 2026
Joe Kucinski
Top 10 WORST Corvette Engineering Failures of All Time!
Joe Kucinski
10 Records the C8 Corvette Generation Has SMASHED (& 1 Glaring Failure)
Joe Kucinski
7 Wildest Corvette Concepts Ever Made
Brett Foote
Advanced
Joined: Feb 2007
Posts: 73
Likes: 0
From: Burien Washington
I copied the link and put it in a word document and saved it on my desktop. This way I will always have it and will also be able to give it to anyone who needs it. This is such great information
Burning Brakes
Joined: Jul 2004
Posts: 1,246
Likes: 21
From: Prescott, AZ
Thanks to this thread I was able to fix my problem with the ignition switch. Car would start and then die or not start at all. After reading all 90 pages of this thread, check all under hood grounds, looked like new, then determined it was the switch. Corvette runs great now. Best thing didn't have to take it to the Dealer.
Advanced
Joined: Jun 2014
Posts: 54
Likes: 0
I just had the transmission and rear diff upgraded in my 04 Z06. When I picked it up today the speedometer was acting all funny and jumping around. Also a few different waring messages came up. After driving about 15min the car sputtered and the check engine light came on. From that point on the car was sputtering real bad if I gave it gas but I was OK since I was on the interstate. When I got off the exit ramp the car shut off. It would restart but every time I tried to pull out it would sputter and stall. After about 10 restarts and playing with the clutch I got it going again. Does anyone have any idea what the problem could be? Seems like an electrical issue to me. Thanks for the help.
Melting Slicks
Joined: Jul 2002
Posts: 2,375
Likes: 39
From: Charlotte NC
Any assistance you can offer would be greatly appreciated. Or anyone else who happens to have these answers.
Thank you very much for all of your time spent and dedication helping others.
Last edited by ForceFedC5; Oct 12, 2016 at 12:07 PM. Reason: Located a few more..
Drifting
Joined: Oct 2009
Posts: 1,721
Likes: 237
From: marietta, GA
I've been following this thread would appreciate knowing which ground(s) need cleaning. After picking up dinner last night the car started fine but the windows would not work and all the gauges were at 0 also got the traction message. Codes are P1689, P1571 C1277. Any suggestion as how to clean them. Thank you
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've been following this thread would appreciate knowing which ground(s) need cleaning. After picking up dinner last night the car started fine but the windows would not work and all the gauges were at 0 also got the traction message. Codes are P1689, P1571 C1277. Any suggestion as how to clean them. Thank you
Bill
Drifting
Joined: Oct 2009
Posts: 1,721
Likes: 237
From: marietta, GA
Hi Bill; It's a 2003 manual, 35,000 miles. When this first happened Tuesday I cleared the codes then took a ride and all was well. Wednesday AM start up was fine but when I got back in the car after the gym it happened again so when I got home I shut the car down then retrieved the codes so I believe they were an H. I appreciate your help. Peter
Melting Slicks
Joined: Jul 2002
Posts: 2,375
Likes: 39
From: Charlotte NC
So my 2000 C5 has been having the standard traction control/active handling/charging issues that more or less come with this car after years of ownership. The mechanic I have helping me is a very thorough and precise technician (he's actually an aircraft mechanic), however we are having problems locating some of the other grounds to clean. We have successfully located and cleaned some locations but cannot locate 2,5,12,13. Please keep in mind that my car is modded so it's quite possible that additional hardware is blocking the view of something obvious on other stock c5's. Also, where is 11 supposed to connect to?
Any assistance you can offer would be greatly appreciated. Or anyone else who happens to have these answers.
Thank you very much for all of your time spent and dedication helping others.
Any assistance you can offer would be greatly appreciated. Or anyone else who happens to have these answers.
Thank you very much for all of your time spent and dedication helping others.
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
Hi Bill; It's a 2003 manual, 35,000 miles. When this first happened Tuesday I cleared the codes then took a ride and all was well. Wednesday AM start up was fine but when I got back in the car after the gym it happened again so when I got home I shut the car down then retrieved the codes so I believe they were an H. I appreciate your help. Peter
1. Wetted BCM due to HVAC Air Box condensation draining into the passengers foot well because the air box drain is clogged.
OR
2. The LEFT and or RIGHT Door power plug has damaged /spread apart female pins and is making POOR CONTACT with the male pins thus causing the LEFT and or RIGHT door control module to turn ON & OFF, ON & OFF repeatedly. This condition causes the effected modules to corrupt the serial data buss. When that happen, you SEE it just as you are in the IPC.
SO,,,,,,,,,,,,,,,,,,,,,,,,,,,, I would start investigating those two things.
Bill
Drifting
Joined: Oct 2009
Posts: 1,721
Likes: 237
From: marietta, GA
IMHO,,,,,,,,,,,,, Grounds are NOT causing your issues. The most common causes of this type of issue/ problem can be caused by TWO things:
1. Wetted BCM due to HVAC Air Box condensation draining into the passengers foot well because the air box drain is clogged.
OR
2. The LEFT and or RIGHT Door power plug has damaged /spread apart female pins and is making POOR CONTACT with the male pins thus causing the LEFT and or RIGHT door control module to turn ON & OFF, ON & OFF repeatedly. This condition causes the effected modules to corrupt the serial data buss. When that happen, you SEE it just as you are in the IPC.
SO,,,,,,,,,,,,,,,,,,,,,,,,,,,, I would start investigating those two things.
Bill
1. Wetted BCM due to HVAC Air Box condensation draining into the passengers foot well because the air box drain is clogged.
OR
2. The LEFT and or RIGHT Door power plug has damaged /spread apart female pins and is making POOR CONTACT with the male pins thus causing the LEFT and or RIGHT door control module to turn ON & OFF, ON & OFF repeatedly. This condition causes the effected modules to corrupt the serial data buss. When that happen, you SEE it just as you are in the IPC.
SO,,,,,,,,,,,,,,,,,,,,,,,,,,,, I would start investigating those two things.
Bill
Cruising
Joined: Oct 2016
Posts: 11
Likes: 0
From: Coquitlam B.C.
Hey Bill,
I recently started having misfires after prolonged exposure of the car to rain. We had a ffew major storms come thru and the car was parked outside. I have a garage I can put the car in over the winter starting this weekend but need to find the source of the misfires. Once the car is warmed up, the misfire issue seems to improve alot but not 100%.
Do you think this ground issue could be the culprit. If so, can you steer me to the grounds that would most likely contribute. Probably mainly in the engine compartment area but any advice would help.
Cheers
Paul
P.S - I ordered new plug wires on spec and will change the plugs as well when I get the wires.
I recently started having misfires after prolonged exposure of the car to rain. We had a ffew major storms come thru and the car was parked outside. I have a garage I can put the car in over the winter starting this weekend but need to find the source of the misfires. Once the car is warmed up, the misfire issue seems to improve alot but not 100%.
Do you think this ground issue could be the culprit. If so, can you steer me to the grounds that would most likely contribute. Probably mainly in the engine compartment area but any advice would help.
Cheers
Paul
P.S - I ordered new plug wires on spec and will change the plugs as well when I get the wires.