Cascading Codes
03-16-2017, 09:02 AM
#1
Racer
Thread Starter
Cascading Codes
Did search, but this one might be a one off. 03 Z06, 135K miles, new rebuilt motor. Okay, the car was doing this before the new motor, but now it has gone to a new level.
10 PCM
P1626H
28 TCS
U1301H
C1288H
40 BCM
U1255H
U1096H
U1016H
58 SDM
U1301H
60 IPC
U1255H
U1160H
U1064H
U1016H
U1040H
U1176H
U1088H
80 Radio
U1064H
U1016H
U1096H
99 HVAC
U1064H
U1096H
U1160H
U1255H
AO-LDCM
No Comm
A1-RDCM
B2283H
U2285H
U1255H
U1016H
U1096H
A6-SCM
U1300H
U1255H
U1016H
U1064H
BO-RFA
U1255H
U1064H
U1096H
U1016H
Ugh. Apologies boring you to death. I get a mix of "Reduce Power" or "Service Active Handling" warnings, gas gauge goes from full to empty with low fuel warning, the driver's side door panel for the window, etc. goes dead..........it's a mixed bag each time, but it looks like a pinball machine. I can stop the car, pull key, and do a reboot and everything is fine. I'm starting to suspect the little black box in the passenger side fender, behind the wheel. Any thoughts?
10 PCM
P1626H
28 TCS
U1301H
C1288H
40 BCM
U1255H
U1096H
U1016H
58 SDM
U1301H
60 IPC
U1255H
U1160H
U1064H
U1016H
U1040H
U1176H
U1088H
80 Radio
U1064H
U1016H
U1096H
99 HVAC
U1064H
U1096H
U1160H
U1255H
AO-LDCM
No Comm
A1-RDCM
B2283H
U2285H
U1255H
U1016H
U1096H
A6-SCM
U1300H
U1255H
U1016H
U1064H
BO-RFA
U1255H
U1064H
U1096H
U1016H
Ugh. Apologies boring you to death. I get a mix of "Reduce Power" or "Service Active Handling" warnings, gas gauge goes from full to empty with low fuel warning, the driver's side door panel for the window, etc. goes dead..........it's a mixed bag each time, but it looks like a pinball machine. I can stop the car, pull key, and do a reboot and everything is fine. I'm starting to suspect the little black box in the passenger side fender, behind the wheel. Any thoughts?
03-16-2017, 11:37 AM
#2
Racer
Thread Starter
Did search, but this one might be a one off. 03 Z06, 135K miles, new rebuilt motor. Okay, the car was doing this before the new motor, but now it has gone to a new level.
10 PCM
P1626H
28 TCS
U1301H
C1288H
40 BCM
U1255H
U1096H
U1016H
58 SDM
U1301H
60 IPC
U1255H
U1160H
U1064H
U1016H
U1040H
U1176H
U1088H
80 Radio
U1064H
U1016H
U1096H
99 HVAC
U1064H
U1096H
U1160H
U1255H
AO-LDCM
No Comm
A1-RDCM
B2283H
U2285H
U1255H
U1016H
U1096H
A6-SCM
U1300H
U1255H
U1016H
U1064H
BO-RFA
U1255H
U1064H
U1096H
U1016H
Ugh. Apologies boring you to death. I get a mix of "Reduce Power" or "Service Active Handling" warnings, gas gauge goes from full to empty with low fuel warning, the driver's side door panel for the window, etc. goes dead..........it's a mixed bag each time, but it looks like a pinball machine. I can stop the car, pull key, and do a reboot and everything is fine. I'm starting to suspect the little black box in the passenger side fender, behind the wheel. Any thoughts?
10 PCM
P1626H
28 TCS
U1301H
C1288H
40 BCM
U1255H
U1096H
U1016H
58 SDM
U1301H
60 IPC
U1255H
U1160H
U1064H
U1016H
U1040H
U1176H
U1088H
80 Radio
U1064H
U1016H
U1096H
99 HVAC
U1064H
U1096H
U1160H
U1255H
AO-LDCM
No Comm
A1-RDCM
B2283H
U2285H
U1255H
U1016H
U1096H
A6-SCM
U1300H
U1255H
U1016H
U1064H
BO-RFA
U1255H
U1064H
U1096H
U1016H
Ugh. Apologies boring you to death. I get a mix of "Reduce Power" or "Service Active Handling" warnings, gas gauge goes from full to empty with low fuel warning, the driver's side door panel for the window, etc. goes dead..........it's a mixed bag each time, but it looks like a pinball machine. I can stop the car, pull key, and do a reboot and everything is fine. I'm starting to suspect the little black box in the passenger side fender, behind the wheel. Any thoughts?
03-16-2017, 12:48 PM
#3
Racer
Thread Starter
2 1/2 hours and no one responded with a solution!!!!!
Impatient aren't we this morning????
Post back what you find..........
Codes can be pulled with the engine running. To do so you need to use the RESET button to clear all messages displayed in the DIC and then pull codes as normal........
Impatient aren't we this morning????
Post back what you find..........
Codes can be pulled with the engine running. To do so you need to use the RESET button to clear all messages displayed in the DIC and then pull codes as normal........
Good stuff. I'll run the traps this weekend. Darn work is getting in the way of wrenching.
03-16-2017, 02:21 PM
#5
Melting Slicks
My first reaction would be to check the connectors near the accordions in the doors. With the accordion separated from the chassis side, pull the wire bundle out of the chassis to reveal the connector. Check to make sure the male / female connections are clean and tight. Takes 20 - 30 minutes to do both doors. If that doesn't work, then follow 8VETTE7's advice. My bet is your driver's side connection is loose.
A quick and dirty way to check is get the car running without the dash going crazy then open the door, grab the door accordion, and wiggle it. If symptoms appear, you likely found the culprit.
A quick and dirty way to check is get the car running without the dash going crazy then open the door, grab the door accordion, and wiggle it. If symptoms appear, you likely found the culprit.
03-17-2017, 10:12 AM
#6
Drifting
That you posted this...
... points to what is posted above about the accordion connector on the door. That can be checked easily.
After that indeed go to what 8VETTE7 posted. It's going to be far from "fun"
After that indeed go to what 8VETTE7 posted. It's going to be far from "fun"
03-17-2017, 12:34 PM
#7
Tech Contributor
Member Since: Dec 1999
Location: Anthony TX
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
I agree with 8VETTE7. 
That's why the STAR CONNECTORS are there!
If you will look close at the serial data buss schematic, you will see that the STAR 2 connector deals with the LDCM, RDCM and the SCM... HMMMMM,,, GM must have known that those three modules would be the MOST PROBLEMATIC ones in our C5s..
You can EASILY pop out the shorting buss on the STAR 2 Connector, clear ALL the DTCs and see what happens.
If you stop cascading DTCs, one or more of those modules is causing the issues!
YES, you will see NO COMMS on all three of those modules BUT, ALL the other modules will be or should be working and communicating like normal again if anything on the STAR 2 buss was causing problems.
Bill
That's why the STAR CONNECTORS are there! If you will look close at the serial data buss schematic, you will see that the STAR 2 connector deals with the LDCM, RDCM and the SCM... HMMMMM,,, GM must have known that those three modules would be the MOST PROBLEMATIC ones in our C5s..
You can EASILY pop out the shorting buss on the STAR 2 Connector, clear ALL the DTCs and see what happens.
If you stop cascading DTCs, one or more of those modules is causing the issues!
YES, you will see NO COMMS on all three of those modules BUT, ALL the other modules will be or should be working and communicating like normal again if anything on the STAR 2 buss was causing problems.
Bill
03-17-2017, 12:36 PM
#8
Tech Contributor
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Location: Anthony TX
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
Once you complete that troubleshooting and provide the results,, we can further lead, guide and direct to solve the issue. 
04-03-2017, 12:47 PM
#9
Racer
Thread Starter
I noticed that I had wired the power for my laser jammers to a fuse in the box. Pulled that wire. Cleared codes. Nothing has returned.
Driven the car for over a week. Happy Z.I did the shorting bar diagnostic, and everything was fine. No codes were produced with each test. Could a simple power source feed (maybe short in the jammer equipment cause this?
Last edited by Evil Oil Apologist; 04-03-2017 at 01:48 PM.
04-03-2017, 03:56 PM
#10
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Member Since: Dec 1999
Location: Anthony TX
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
IF,,,,you have a 1997-2003, look above the BCM and to the LEFt, you will see a 8" three wire pig tail. If it has never been disturbed, it will be terminated in silver duct tape. The wires are: ORANGE 12 Volt DC Battery, Yellow Switched 12 VDC Power and BLACK (Chassis Ground).
That is the AUX Power wires that you need to use. They are 20 AMP fused and designed to power your installed stuff.
You can actually remove the pigtail connector and work on the wires out in the open.
BC
That is the AUX Power wires that you need to use. They are 20 AMP fused and designed to power your installed stuff.
You can actually remove the pigtail connector and work on the wires out in the open.
BC
04-03-2017, 04:44 PM
#11
Racer
Thread Starter
IF,,,,you have a 1997-2003, look above the BCM and to the LEFt, you will see a 8" three wire pig tail. If it has never been disturbed, it will be terminated in silver duct tape. The wires are: ORANGE 12 Volt DC Battery, Yellow Switched 12 VDC Power and BLACK (Chassis Ground).
That is the AUX Power wires that you need to use. They are 20 AMP fused and designed to power your installed stuff.
You can actually remove the pigtail connector and work on the wires out in the open.
BC
That is the AUX Power wires that you need to use. They are 20 AMP fused and designed to power your installed stuff.
You can actually remove the pigtail connector and work on the wires out in the open.
BC
