HELP! Some major electrical problems
10-07-2010, 09:55 AM
#1
Race Director
Thread Starter
HELP! Some major electrical problems
Car has been running fine. 2002 C5. Nothing out of the ordinary, no codes, everything good.
That was until this morning when I pulled it out of the garage. First thing I noticed was that my passenger window wouldn't go down. As I was holding the button, it went into reduced power mode, then the radio shut off, fuel gage went down, TPMS started reporting "check tire pressure", etc.
I shut off, pulled key, turned back on and cleared all the codes. Tried the passenger window again (drivers worked fine) and it did the same thing.
I shut off again, pulled key, put key back into run position, got out and opened passenger door to see if window was stuck, and it worked fine from the passenger side. Closed door, worked from drivers side control. Started car up, and stopped working, but no codes.
Start driving to work and get hit with the reduced power, loss of radio, etc. Clear all the codes again, and it happens again after a few minutes. Not willing to risk it, turned back home. At one point, I shut the car off (don't pull key), and restart engine and everything comes back fine except for the "security" light on the dashboard. A little while later, the reduced engine power comes on again along with all the other gremlins. Strange part, is I've been in reduced power mode before, and the engine didn't seem to be affected. Car absolutely was not in reduced power mode since I was able to WOT to 65mph. That wouldn't happen if it was truely in Reduced Power Mode.
This hopefully shouldn't matter much, but I did drive it in rain a few days ago.
I didn't have some paper with me to get down all the codes, so I'll do a follow up post but it had 1 PCM, 1 TCM, 3 BCM, 7 of another and at one time was reporting loss of communication with the RCM.
I'm fairly certain it has to do with the computers or electrical connections in the car. But I'm sort of at a loss of where to start troubleshooting.
**Cliffs**
Car started this morning
Noticed Passenger Window stopped working
Got Reduced Power Mode in DIC and chime
ABS and TC light went on in cluster
Service Engine Soon in DIC
Radio shut off
Fuel gage dropped to E in cluster and "Low Fuel" in DIC
"Low Tire Pressure" in DIC
That was until this morning when I pulled it out of the garage. First thing I noticed was that my passenger window wouldn't go down. As I was holding the button, it went into reduced power mode, then the radio shut off, fuel gage went down, TPMS started reporting "check tire pressure", etc.
I shut off, pulled key, turned back on and cleared all the codes. Tried the passenger window again (drivers worked fine) and it did the same thing.
I shut off again, pulled key, put key back into run position, got out and opened passenger door to see if window was stuck, and it worked fine from the passenger side. Closed door, worked from drivers side control. Started car up, and stopped working, but no codes.
Start driving to work and get hit with the reduced power, loss of radio, etc. Clear all the codes again, and it happens again after a few minutes. Not willing to risk it, turned back home. At one point, I shut the car off (don't pull key), and restart engine and everything comes back fine except for the "security" light on the dashboard. A little while later, the reduced engine power comes on again along with all the other gremlins. Strange part, is I've been in reduced power mode before, and the engine didn't seem to be affected. Car absolutely was not in reduced power mode since I was able to WOT to 65mph. That wouldn't happen if it was truely in Reduced Power Mode.
This hopefully shouldn't matter much, but I did drive it in rain a few days ago.
I didn't have some paper with me to get down all the codes, so I'll do a follow up post but it had 1 PCM, 1 TCM, 3 BCM, 7 of another and at one time was reporting loss of communication with the RCM.
I'm fairly certain it has to do with the computers or electrical connections in the car. But I'm sort of at a loss of where to start troubleshooting.
**Cliffs**
Car started this morning
Noticed Passenger Window stopped working
Got Reduced Power Mode in DIC and chime
ABS and TC light went on in cluster
Service Engine Soon in DIC
Radio shut off
Fuel gage dropped to E in cluster and "Low Fuel" in DIC
"Low Tire Pressure" in DIC
10-07-2010, 10:21 AM
#2
Race Director
Thread Starter
I'll check that, thanks.
On restart just now, all the codes cleared from current condition and everything appeared normal.
Here's the list of codes:
PCM:
P1626 H
TCS:
U1301 H
U1000 H
BCM:
U1255 H
U1016 H
U1096 H
SDM:
U1000 H
U1301 H
U1064 H
IPC:
U1255 H
U1016 H
U1064 H
U1040 H
U1176 H
U1088 H
U1160 H
Radio:
U1064 H
U1076 H
U1016 H
HVAC:
U1064 H
U1096 H
U1160 H
U1255 H
LDCM:
U1064 H
RDCM
No comm
SCM:
U1300 H
U1255 H
BO-RFA:
U1255 H
U1016 H
On restart just now, all the codes cleared from current condition and everything appeared normal.
Here's the list of codes:
PCM:
P1626 H
TCS:
U1301 H
U1000 H
BCM:
U1255 H
U1016 H
U1096 H
SDM:
U1000 H
U1301 H
U1064 H
IPC:
U1255 H
U1016 H
U1064 H
U1040 H
U1176 H
U1088 H
U1160 H
Radio:
U1064 H
U1076 H
U1016 H
HVAC:
U1064 H
U1096 H
U1160 H
U1255 H
LDCM:
U1064 H
RDCM
No comm
SCM:
U1300 H
U1255 H
BO-RFA:
U1255 H
U1016 H
10-07-2010, 10:41 AM
#3
Race Director
Thread Starter
You mentioned driving the car in the rain recently so, on the passenger side is the carpet wet??? If so pull the toe kick and check on the BCM for any signs of water stains. If the carpet is wet you need to get it out of the car to dry. If there are signs of water on or around the battery you will want to disconnect the battery and pull the BCM to check it further. It's possible that there is moisture inside the metal container and the BCM board needs to be dried out. Hait dryer will accomplish that.
Next possibility is the bare wire in the rubber accordian tube between the doors and body, Here's a Bill Curlee thread link about identifying and correcting that problem:
http://forums.corvetteforum.com/c5-t...n-long-32.html
Then go to post #640.
Check BOTH doors
Next possibility is the bare wire in the rubber accordian tube between the doors and body, Here's a Bill Curlee thread link about identifying and correcting that problem:
http://forums.corvetteforum.com/c5-t...n-long-32.html
Then go to post #640.
Check BOTH doors
10-07-2010, 01:41 PM
#4
Race Director
Thread Starter
With all those U codes you need to check grounds. G104 is the ground point for the BCM and since your U codes are across all subsystems you need to look for something common to all subsystems. More on grounds can be found in yet another Bill Curlee thread :
http://forums.corvetteforum.com/c5-t...tion-long.html
http://forums.corvetteforum.com/c5-t...tion-long.html
I knew it had to be something like a bad ground or short. No way all those systems would crap out like that at once.
I checked the door conduit and some ground points and didn't find anything. Fuses and BCM completely dry, no issues there.
I did an extra tightening of the battery terminals, just to make sure.
As of yet, the issue hasn't reappeared. Just drove 30 minutes to work with no codes, so hopefully that was it.
