I just got my EBCM back from ABSFixers and when I started the car I am still getting all the ABS/Service Traction etc lights. I cleared the computer of all history codes and the C1265 will not go away. What's next? This is (*&@!^*(* )ing me off!!!

Please point me in the right direction.
Jim

Car is a 2001.

 

Before you sent out your part for repair, did you try cleaning the ground connections on the frame near the alternator? Twice I've had the codes and cleaning the grounds eliminated the problem. The second time I did a much better job of cleaning, so hopefully it won't happen again. Try the grounds first before going any further.

 

You may need to replace the BPMV. Here is the diagnostic procedure for a 2001 plus the procedure for 2000. The 2000 is more detailed but the 2001 procedure is probably a recognition by GM that the more detailed information in previous manuals didn't help the tech isolate the problem any better. The C1265 code indicates the Left Rear solenoid didn't get the proper voltage or the solenoid itself has a problem. The EBCM controls the voltage to the solenoids but they are actually located in the BPMV. If there is a problem with a solenoid it could be time to replace the BPMV. Follow the steps where you check the resistance between various connector pins on the BPMV and between those pins and the BPMV case.

From the 2001 Service Manual
DTC C1261-C1274

Circuit Description
The system relay is energized when the ignition is ON. The system relay supplies voltage to the valve solenoids and the pump motor. This voltage is referred to as the system voltage. The electronic brake control module (EBCM) microprocessor activates the valve solenoids by grounding the control circuit.

Conditions for Running the DTC
• The system voltage is greater than 8 volts.
• The ignition voltage is greater than 9 volts.

Conditions for Setting the DTC
The commanded state of the driver and the actual state of the control circuit do not match for 0.03 seconds.

Action Taken When the DTC Sets
If equipped, the following actions occur:
• The EBCM disables the ABS/TCS/VSES for the duration of the ignition cycle.
• The DRP does not function optimally.
• The ABS indicator turns ON.
• The Traction Control and Active Handling indicator turns ON.
• The DIC displays the following messages:
o Service ABS
o Service Traction System
o Service Active Handling

Conditions for Clearing the DTC
• The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
• The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

Diagnostic Aids
The solenoid valve circuit is internal to the EBCM. The solenoid valve circuit is not diagnosable external to the EBCM. The DTC sets when there is a malfunction in the solenoid circuit internal to the EBCM.

Test Description
The number below refers to the step number on the diagnostic table.
Step 2. Determines whether the DTC is current.
Step Action Yes No
Schematic Reference: ABS Schematics

Step 1 Did you perform the ABS Diagnostic System Check? Go to Step 2
Go to Diagnostic System Check - ABS

Step 2
1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Use the scan tool in order to clear the DTCs.
4. With the scan tool, perform the Automated Test.
Does the DTC reset as a current DTC? Go to Step 3
Go to Testing for Intermittent and Poor Connections in Wiring Systems

Step 3 Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .
Did you complete the repair? Go to Step 4
--
Step 4 1. Use the scan tool in order to clear the DTCs.
2. With the scan tool, perform the Automated Test.
Does the DTC reset? Go to Step 2
System OK

From the 2000 Service Manual
DTC C1265 LR Inlet Valve Solenoid Malfunction

Circuit Description
The Inlet valve solenoid circuits are supplied with battery power when the ignition is in the ON position. The EBCM controls the valve functions by grounding the circuit when necessary.
Conditions for Setting the DTC
The EBCM senses a discrepancy such as an open, short to ground, or short to voltage in the circuit.

Action Taken When the DTC Sets
ABS/TCS/Active Handling (if equipped with RPO JL4) are disabled.
• Indicators that turn on:
o ABS indicator
o Car Icon (TCS indicator)
• Messages displayed on the DIC:
o Service ABS
o Service Traction System
o Service Active HNDLG (if equipped with Active Handling RPO JL4)

Conditions for Clearing the DTC
• Condition for DTC is no longer present and scan tool clear DTC function is used.
• Fifty ignition cycles have passed with no DTCs detected.

Diagnostic Aids
Make sure the integrity of the connection between the EBCM and the BPMV is secure, tight, and free from corrosion.

Test Description
The numbers below refer to step numbers on the diagnostic table.
Step 3. Checks the resistance value of the solenoid.
Step 4. Checks for a short to ground in the BPMV.
Step 7. Checks for an internal short to voltage.

DTC C1265 LR Inlet Valve Solenoid Malfunction
Step
Action Value(s) Yes No
Step 1 Was the Diagnostic System Check performed? -- Go to Step 2
Go to Diagnostic System Check - ABS

Step 2 1. Turn the ignition switch to the OFF position.
2. Disconnect the EBCM connector.
3. Remove the EBCM from the BPMV.
4. Inspect the EBCM to BPMV connector for conditions which could cause intermittents such as damage, corrosion, or poor terminal contact.
Are internal connectors OK and cavity free of brake fluid? -- Go to Step 3
Go to Step 6

Step 3
1. Install J 41247 BPMV Pinout Box to the BPMV connector.
2. Using J 39200 DMM, measure the resistance between J 41247 terminals 2 and 7.
Is the resistance within the range specified in the value(s) column? 8-12 ohms Go to Step 4
Go to Step 8

Step 4
Using J 39200 DMM, measure the resistance between J 41247 terminal 2 and the BPMV case.
Is the resistance within the range specified in the value(s) column? OL (infinite) Go to Step 5
Go to Step 8

Step 5 1. Remove J 41247 .
2. Reinstall the EBCM to BPMV.
3. Reconnect the EBCM connector.
4. Turn the ignition switch to the ON position, engine off.
Does DTC C1265 reset as a current DTC? -- Go to Step 9
Go to Step 7

Step 6 1. If connector corrosion or damage are present, replace BPMV and/or EBCM as necessary.
2. If brake fluid is present, replace both the BPMV and EBCM.
Is the repair complete? -- Go to Diagnostic System Check - ABS
--
Step 7
Using a scan tool in ABS/TCS or ABS/TCS/Active Handling Special Functions run the AUTOMATED Test.
Does DTC C1265 reset as a current DTC? -- Go to Step 8
Go to Diagnostic System Check - ABS

Step 8 Replace the BPMV. Refer to Brake Pressure Modulator Valve (BPMV) Replacement .
Is the replacement complete? -- Go to Diagnostic System Check - ABS
--
Step 9 Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .
Is the replacement complete? -- Go to Diagnostic System Check - ABS
--

Bill