Massive Electrical problems...ple@se
11-11-2018, 02:21 AM
#1
Drifting
Thread Starter
Massive Electrical problems...please help
I could really use some help here. I have some crazy electrical gremlins going on. Last year, I had my car retuned by a reputable tuner. He changed out my PCM because the previous tuner(s) really messed up my car and the Vin numbers didnt match. The car runs great, better than before. I have been to one track day, with no issues.
However, I have been experiencing tons of electrical issues that I didn’t have before. The weird thing is that these problems gradually started cropping up over the last year.
Here are some the symptoms:
No climate control - it won’t power on, but the led lights will illluminate.
No stereo - won’t power on
No ABS - dash lights on, DIC codes says No Comm.
Power to radar detector went out - was hardwired pulling power from the rear view mirror.
Passenger door wouldn’t unlock*
Passenger window wouldn’t open or close*
* These issues seemed to have fixed themselves...weird
And the codes:
PCM P0102 H
PCM P0135 C
PCM P0155 C
PCM P1571 H C
PCM P1689 H C
BCM 0432 H C
BCM B2587
BCM B0502
BCM B0507 H
BCM B2527
BCM B2482 H
BCM B2592
TCM No Comm.
SCM U1040 H C
HVAC No Comm.
LDCM B2284 H
RDCM B2285 H
RFA U1000
I checked the fuses and changed the battery. What would be the best way to trouble shoot these issues? I have no idea where all the modules are located. Can some one point me to some info on the electrical system?
TIA,
John
However, I have been experiencing tons of electrical issues that I didn’t have before. The weird thing is that these problems gradually started cropping up over the last year.
Here are some the symptoms:
No climate control - it won’t power on, but the led lights will illluminate.
No stereo - won’t power on
No ABS - dash lights on, DIC codes says No Comm.
Power to radar detector went out - was hardwired pulling power from the rear view mirror.
Passenger door wouldn’t unlock*
Passenger window wouldn’t open or close*
* These issues seemed to have fixed themselves...weird
And the codes:
PCM P0102 H
PCM P0135 C
PCM P0155 C
PCM P1571 H C
PCM P1689 H C
BCM 0432 H C
BCM B2587
BCM B0502
BCM B0507 H
BCM B2527
BCM B2482 H
BCM B2592
TCM No Comm.
SCM U1040 H C
HVAC No Comm.
LDCM B2284 H
RDCM B2285 H
RFA U1000
I checked the fuses and changed the battery. What would be the best way to trouble shoot these issues? I have no idea where all the modules are located. Can some one point me to some info on the electrical system?
TIA,
John
Last edited by jpandes; 11-11-2018 at 02:50 AM.
11-11-2018, 08:46 AM
#2
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11-11-2018, 09:17 AM
#3
Melting Slicks
The first step is to check the battery voltage using a VOM at the terminals with the car off. If it is below 12.5V it can lead to all sorts of electrical gremlins. TheU1040, P1571 and 1689 codes are related to the Electronic Brake Control Module (EBCM) with those I would check the engine grounds first. Use the search button and look for all the ground points. The P0135=0155 are Oxygen Sensor codes. The B0432 is the rear window defogger. IF the battery voltage is up to par then checking the engine grounds would be the next step, followed by clearing all the codes on the DIC (again use the search button if you do not non how to display them on the DIC) and relist the codes. When a U1040 code shows up it means there was an interruption of voltage to that module. After those are done run the codes run the codes and report back. If the battery does not read the 12.5+V you can try to recharge the battery and let it set over night before retesting.
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Black 03 Z06 (11-11-2018)
11-11-2018, 09:21 AM
#4
Good information Gordy, these cars can be an electrical nightmare and I hope the OP can get it sorted.
11-11-2018, 01:01 PM
#5
Burning Brakes
No Comm could be the module(s) not getting power. Either bad ground or no +12v. My guess is bad contacts in the ignition switch. You can remove the switch and clean the contacts if needed. You would need to remove the knee bolster to get the switch out. I would first check battery voltage as someone else suggested. I would also check the grounding blocks under the hood and make sure they look good.
Here's a link for the service manual, it contains info for the electrical system. https://drive.google.com/open?id=0B1...l9xbGIzV3BtcjA
Here's a link for the service manual, it contains info for the electrical system. https://drive.google.com/open?id=0B1...l9xbGIzV3BtcjA
11-11-2018, 09:00 PM
#6
Drifting
Thread Starter
Gordy and Old School,
Thank you for the replies! I appreciate the pointers and the link to the service manual. Unfortunately, the link is no longer working, I’ll try to search for an active download link for the manual myself. I’ll go check the grounds and report back.
Thanks to rwobs777 who pm’d me with a great link to a very helpful video. I’ll post it here so that others might benefit from it, too:
Thank you for the replies! I appreciate the pointers and the link to the service manual. Unfortunately, the link is no longer working, I’ll try to search for an active download link for the manual myself. I’ll go check the grounds and report back.
Thanks to rwobs777 who pm’d me with a great link to a very helpful video. I’ll post it here so that others might benefit from it, too:
11-12-2018, 12:35 PM
#7
Melting Slicks
...No climate control - it won’t power on, but the led lights will illluminate.
No stereo - won’t power on
No ABS - dash lights on, DIC codes says No Comm.
Passenger door wouldn’t unlock* (if from driver's side, it could be modules are not communicating)
Passenger window wouldn’t open or close* (if from driver's side it could be modules are not communicating)
* These issues seemed to have fixed themselves...weird
TCM No Comm.
SCM U1040 H C (the only U1040 I could find is for IPC: Loss of Comm. with TCS)
HVAC No Comm.
LDCM B2284 H (Battery Fault)
RDCM B2285 H (Battery Fault)
RFA U1000 (Loss of Comm. Undetermined)
...I checked the fuses and changed the battery...
No stereo - won’t power on
No ABS - dash lights on, DIC codes says No Comm.
Passenger door wouldn’t unlock* (if from driver's side, it could be modules are not communicating)
Passenger window wouldn’t open or close* (if from driver's side it could be modules are not communicating)
* These issues seemed to have fixed themselves...weird
TCM No Comm.
SCM U1040 H C (the only U1040 I could find is for IPC: Loss of Comm. with TCS)
HVAC No Comm.
LDCM B2284 H (Battery Fault)
RDCM B2285 H (Battery Fault)
RFA U1000 (Loss of Comm. Undetermined)
...I checked the fuses and changed the battery...
I would start by addressing the loss of communication problems. These comunications take place through the Serial Data Bus, and it seems something is not allowing the normal data flow. Once the Serial Data Bus is corrupted all other devices that use it get affected.
This problem has been extensively documented by Bill Curlee and you can read more here. It is usually caused by bad contacts in a connector within the doors' rubber accordion.
The Serial Data Bus goes through the rubber accordion to the door control module. The female pins of the connector on that wire harness get deformed, causing bad contacts and loss of communication/corruption in the Serial Data Bus affecting all modules linked by it.
You can troubleshoot by opening the Star Connector 2 by the passenger's foot well, which isolates both Door Control Modules along with the Left Seat Control Module and, if commucations are restored to the other modules, then you have your culprit(s).
Check the connectors for deformed pins. If bad pins are found you would need to repair the connector (disconnect the battery first), fixing the female pins so they have a positive grip, or replace it. If you want to replace the connector take a look at this post for some ideas.
If connectors are fine, then the problem could be downstream the connectors up to the door control modules, or in the wiring/connector for the driver's seat up to the seat control module.
The Star Connector 2 is the one that has four wires. To perform this test you have to pop the top shorting strip off the top of that connector.
Last edited by GCG; 11-12-2018 at 12:48 PM.
