C5 gremlins, have spent months trying to fix
09-29-2012, 09:50 PM
#1
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St. Jude Donor '11-'12-'13, '16-'17-'18
C5 gremlins, have spent months trying to fix
'02 ZO6 with around 83K on her.
Main issue is, at times, won't crank. Been through all the usual - replaced clutch interlock, new battery (no leakage damage to car), cleaned ignition switch (and when that didn't help, replaced the whole damn thing, including the key pellet contacts), starter interlock relay and even pulled the BCM and resoldered several questionable connections on the power connector. At times, get the "Pull Key for 10 seconds" message but not always.
Car is fine for weeks and then won't crank. And this last time, got the reduced power DIC warning, neither driver nor passenger window would roll up and neither side door would lock. And, at times, auto seat movement doesn't work either.
Oh yea, checked the grounds on the frame - no corrosion and look fine (had dielectric grease already in 'em).
Codes are as follows (not listing NO CODES display):
10 PCM P1626H
28 TCS U1301H
40 BCM U1255H, U1096H, U1016H
50 SDM U1301H
60 IPC U1255H, U1016H, U1040H
99 HVAC U1064H, U1096H, U1160H, U1255H
A1 RDCM U1064H, U1016H, U1300H
A6 SCM U1300H, 1255H
B0 RFA U1255H, U1064H, U1016H
I know the H means "history" but man! I've had two dealers look at this problem as well and no one seems to have a clue (although there was some talk about a possible serial buss issue?)
Any thoughts at all here?
Main issue is, at times, won't crank. Been through all the usual - replaced clutch interlock, new battery (no leakage damage to car), cleaned ignition switch (and when that didn't help, replaced the whole damn thing, including the key pellet contacts), starter interlock relay and even pulled the BCM and resoldered several questionable connections on the power connector. At times, get the "Pull Key for 10 seconds" message but not always.
Car is fine for weeks and then won't crank. And this last time, got the reduced power DIC warning, neither driver nor passenger window would roll up and neither side door would lock. And, at times, auto seat movement doesn't work either.
Oh yea, checked the grounds on the frame - no corrosion and look fine (had dielectric grease already in 'em).
Codes are as follows (not listing NO CODES display):
10 PCM P1626H
28 TCS U1301H
40 BCM U1255H, U1096H, U1016H
50 SDM U1301H
60 IPC U1255H, U1016H, U1040H
99 HVAC U1064H, U1096H, U1160H, U1255H
A1 RDCM U1064H, U1016H, U1300H
A6 SCM U1300H, 1255H
B0 RFA U1255H, U1064H, U1016H
I know the H means "history" but man! I've had two dealers look at this problem as well and no one seems to have a clue (although there was some talk about a possible serial buss issue?)
Any thoughts at all here?
09-30-2012, 12:10 AM
#2
Team Owner
Have you cleared ALL the codes and then driven the car and then pulled the codes again????
Here is a thread that you want to read through. Many of your codes have this problem written all over them.
http://forums.corvetteforum.com/c5-t...-there-is.html
History codes are important. They are an indication of the problems that have occurred and help in diagnosing what is going on so don't under estimate their value.
Also I would use my backup key to see if it has any effect on the problem. You do have a backup key............
Last comment is that it is NOT good to put dielectric grease on ground connections BEFORE you assemble them and tighten. Dielectric grease is an insulator. Putting it over a ground connection point AFTER it has been assembled and tightened to prevent water infiltration and resulting corrosion IS acceptable.
Here is a thread that you want to read through. Many of your codes have this problem written all over them.
http://forums.corvetteforum.com/c5-t...-there-is.html
History codes are important. They are an indication of the problems that have occurred and help in diagnosing what is going on so don't under estimate their value.
Also I would use my backup key to see if it has any effect on the problem. You do have a backup key............
Last comment is that it is NOT good to put dielectric grease on ground connections BEFORE you assemble them and tighten. Dielectric grease is an insulator. Putting it over a ground connection point AFTER it has been assembled and tightened to prevent water infiltration and resulting corrosion IS acceptable.
All of those comm codes made me think of Bill's thread as well. 
Good luck Ken, hope you track it down.
09-30-2012, 03:22 PM
#3
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St. Jude Donor '11-'12-'13, '16-'17-'18
Well.. taking a look at the codes I pulled:
I'm working my way through the system and checking connections as per the linked thread.
My project for today
P1626 Theft Deterrent System Fuel enable Circuit -C
U1301 Class 2 Circuit Shorted to battery Refer to Data Link Connector System Check in Wiring System
U1255 Serial Data Line malfunction
U1096 Loss of Communications with IPC (No State of Health message)
U1016 Loss Of Communication with PCM (No SOH Message received -RFA
U1040 Loss of Communication with TCS
U1064 Loss of Communications with DCM
U1160 Loss of Communications with LDCM
U1300 Class 2 Circuit Shorted to ground Refer to Data Link connector System Check in Wiring System
U1301 Class 2 Circuit Shorted to battery Refer to Data Link Connector System Check in Wiring System
U1255 Serial Data Line malfunction
U1096 Loss of Communications with IPC (No State of Health message)
U1016 Loss Of Communication with PCM (No SOH Message received -RFA
U1040 Loss of Communication with TCS
U1064 Loss of Communications with DCM
U1160 Loss of Communications with LDCM
U1300 Class 2 Circuit Shorted to ground Refer to Data Link connector System Check in Wiring System
My project for today
09-30-2012, 03:26 PM
#4
Drifting
check the wiring harness to the anything ending in CU or CM.. ECU, PCM, whatever computers there are. cus theres no way 5+ different things are loose instead of 1 central one. that or a dead/dying/shorting/not grounding ECU/PCM/etc maybe..
09-30-2012, 03:36 PM
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St. Jude Donor '11-'12-'13, '16-'17-'18
So I'm pulling them, cleaning them and reinserting
09-30-2012, 04:08 PM
#6
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St. Jude Donor '11-'12-'13, '16-'17-'18
Update: I cleared all codes then pulled the serial jumper with the 4 connections. They looked ok but I cleaned 'em up anyway with some alcohol and Scotchbright (not so hard as to remove the tinning).
Plugged it back in, started the car and pulled codes. Interestingly, NO COMM reported on LDCM, RDCM and SCM and 1 code on HVAC. Tried to clear the HVAC code but it wouldn't clear. So I pulled the jumper again and this time unplugged and plugged it back in several times (old tech trick in case there's some crud on a contact, that will wipe it off). Checked codes again and no comm error this time and was able to clear the 1 code in the HVAC (was a serial buss one).
Tried to start car and it wouldn't crank. So got my wife to hold the key in START (Security relay didn't pull in either) while I poked around all the connections in the footwell. Tapped on the other jumper header (8 or 9 wires in it), the relay pulled in and the car cranked and started. So I pulled THAT jumper and did the cleaning and repeated plugging and unplugging bit. Car cranked right up and no codes
So far, so good......
Plugged it back in, started the car and pulled codes. Interestingly, NO COMM reported on LDCM, RDCM and SCM and 1 code on HVAC. Tried to clear the HVAC code but it wouldn't clear. So I pulled the jumper again and this time unplugged and plugged it back in several times (old tech trick in case there's some crud on a contact, that will wipe it off). Checked codes again and no comm error this time and was able to clear the 1 code in the HVAC (was a serial buss one).
Tried to start car and it wouldn't crank. So got my wife to hold the key in START (Security relay didn't pull in either) while I poked around all the connections in the footwell. Tapped on the other jumper header (8 or 9 wires in it), the relay pulled in and the car cranked and started. So I pulled THAT jumper and did the cleaning and repeated plugging and unplugging bit. Car cranked right up and no codes
So far, so good......
Last edited by KenHorse; 09-30-2012 at 04:11 PM.
09-30-2012, 04:32 PM
#7
Drifting
can you take a pic of the area you're talking about? ill host it on my server for longevity sake. i have no idea what you're talking about and i'd rather learn than wonder from this post :P
09-30-2012, 05:22 PM
#8
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St. Jude Donor '11-'12-'13, '16-'17-'18
Dang.. I didn't think to do that and now everything's all closed up
BUT... here's the two connectors in question, in the yellow circle (no problem hosting it - I placed on my server):
09-30-2012, 05:24 PM
#9
Drifting
i just like all posts with a happy ending being reusable
09-30-2012, 06:40 PM
#10
Team Owner
Update: I cleared all codes then pulled the serial jumper with the 4 connections. They looked ok but I cleaned 'em up anyway with some alcohol and Scotchbright (not so hard as to remove the tinning).
Plugged it back in, started the car and pulled codes. Interestingly, NO COMM reported on LDCM, RDCM and SCM and 1 code on HVAC. Tried to clear the HVAC code but it wouldn't clear. So I pulled the jumper again and this time unplugged and plugged it back in several times (old tech trick in case there's some crud on a contact, that will wipe it off). Checked codes again and no comm error this time and was able to clear the 1 code in the HVAC (was a serial buss one).
Tried to start car and it wouldn't crank. So got my wife to hold the key in START (Security relay didn't pull in either) while I poked around all the connections in the footwell. Tapped on the other jumper header (8 or 9 wires in it), the relay pulled in and the car cranked and started. So I pulled THAT jumper and did the cleaning and repeated plugging and unplugging bit. Car cranked right up and no codes
So far, so good......
Plugged it back in, started the car and pulled codes. Interestingly, NO COMM reported on LDCM, RDCM and SCM and 1 code on HVAC. Tried to clear the HVAC code but it wouldn't clear. So I pulled the jumper again and this time unplugged and plugged it back in several times (old tech trick in case there's some crud on a contact, that will wipe it off). Checked codes again and no comm error this time and was able to clear the 1 code in the HVAC (was a serial buss one).
Tried to start car and it wouldn't crank. So got my wife to hold the key in START (Security relay didn't pull in either) while I poked around all the connections in the footwell. Tapped on the other jumper header (8 or 9 wires in it), the relay pulled in and the car cranked and started. So I pulled THAT jumper and did the cleaning and repeated plugging and unplugging bit. Car cranked right up and no codes
So far, so good......
While there, did you see any signs at all of any previous water intrusion, i.e. staining, dampness, surface rust/corrosion on any of the surrounding area?
Poor drainage of normal A/C condensation inside the HVAC housing, due to either crud inside blocking the drain hole or the drain hose itself being clogged (or both), is one of the culprits of water (condensation) backing up and sometimes coming down in the BCM area OR the feet of whoever's driving at the time.
I'm considering putting some clear plastic over the BCM/Star connectors to act as a sort of raincoat. JIC.
09-30-2012, 06:50 PM
#11
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St. Jude Donor '11-'12-'13, '16-'17-'18
Good news.
While there, did you see any signs at all of any previous water intrusion, i.e. staining, dampness, surface rust/corrosion on any of the surrounding area?
Poor drainage of normal A/C condensation inside the HVAC housing, due to either crud inside blocking the drain hole or the drain hose itself being clogged (or both), is one of the culprits of water (condensation) backing up and sometimes coming down in the BCM area OR the feet of whoever's driving at the time.
I'm considering putting some clear plastic over the BCM/Star connectors to act as a sort of raincoat. JIC.
While there, did you see any signs at all of any previous water intrusion, i.e. staining, dampness, surface rust/corrosion on any of the surrounding area?
Poor drainage of normal A/C condensation inside the HVAC housing, due to either crud inside blocking the drain hole or the drain hose itself being clogged (or both), is one of the culprits of water (condensation) backing up and sometimes coming down in the BCM area OR the feet of whoever's driving at the time.
I'm considering putting some clear plastic over the BCM/Star connectors to act as a sort of raincoat. JIC.
(fingers crossed!)
03-03-2018, 02:20 PM
#12
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C5 Start/no run condition Gremlins:
My car has a start/no run issue also, but it's intermittent. Checked everything you had and then some. Sometimes it starts right up, the next day spins over, but no fire(run). Other times it works perfectly for days, the the next time, back to the same thing. 3 weeks ago, it starts and runs, and has been running everyday since.....until this morning, nothing!!!....However, I get in it a little later and closed the door a little harder out of some aggravation, turn the key to start and it runs for a second or 2 and dies...I close the door the same way twice and it runs for a few more seconds and dies. Then I slam the door pretty hard and it runs and stays running.....Just for a test, I get out, get back in it, close the door normal and it starts and runs perfectly!......I believe I scanned over a post on youtube about the door module effecting the starting of the car. Don't know if you ever got yours to run, but if not try slamming the door, lol. Works for me 
'02 ZO6 with around 83K on her.
Main issue is, at times, won't crank. Been through all the usual - replaced clutch interlock, new battery (no leakage damage to car), cleaned ignition switch (and when that didn't help, replaced the whole damn thing, including the key pellet contacts), starter interlock relay and even pulled the BCM and resoldered several questionable connections on the power connector. At times, get the "Pull Key for 10 seconds" message but not always.
Car is fine for weeks and then won't crank. And this last time, got the reduced power DIC warning, neither driver nor passenger window would roll up and neither side door would lock. And, at times, auto seat movement doesn't work either.
Oh yea, checked the grounds on the frame - no corrosion and look fine (had dielectric grease already in 'em).
Codes are as follows (not listing NO CODES display):
10 PCM P1626H
28 TCS U1301H
40 BCM U1255H, U1096H, U1016H
50 SDM U1301H
60 IPC U1255H, U1016H, U1040H
99 HVAC U1064H, U1096H, U1160H, U1255H
A1 RDCM U1064H, U1016H, U1300H
A6 SCM U1300H, 1255H
B0 RFA U1255H, U1064H, U1016H
I know the H means "history" but man! I've had two dealers look at this problem as well and no one seems to have a clue (although there was some talk about a possible serial buss issue?)
Any thoughts at all here?
Main issue is, at times, won't crank. Been through all the usual - replaced clutch interlock, new battery (no leakage damage to car), cleaned ignition switch (and when that didn't help, replaced the whole damn thing, including the key pellet contacts), starter interlock relay and even pulled the BCM and resoldered several questionable connections on the power connector. At times, get the "Pull Key for 10 seconds" message but not always.
Car is fine for weeks and then won't crank. And this last time, got the reduced power DIC warning, neither driver nor passenger window would roll up and neither side door would lock. And, at times, auto seat movement doesn't work either.
Oh yea, checked the grounds on the frame - no corrosion and look fine (had dielectric grease already in 'em).
Codes are as follows (not listing NO CODES display):
10 PCM P1626H
28 TCS U1301H
40 BCM U1255H, U1096H, U1016H
50 SDM U1301H
60 IPC U1255H, U1016H, U1040H
99 HVAC U1064H, U1096H, U1160H, U1255H
A1 RDCM U1064H, U1016H, U1300H
A6 SCM U1300H, 1255H
B0 RFA U1255H, U1064H, U1016H
I know the H means "history" but man! I've had two dealers look at this problem as well and no one seems to have a clue (although there was some talk about a possible serial buss issue?)
Any thoughts at all here?
