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C0265 - EBCM Relay Circuit

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Old 08-07-2007, 06:58 PM
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Default C0265 - EBCM Relay Circuit

C0265 - EBCM Relay Circuit

Can anybody tell me how to troubleshoot this problem?
Old 08-07-2007, 08:53 PM
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there is a bulletin about the ground that is bolted to the frame underneath the front drivers door. Take it loose and clean the frame and reground it with a star washer. Didnt you just replace your frame??? I would check that, cause if not that relay is internal to the ebcm
Old 08-08-2007, 06:58 AM
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Well, i'm pretty sure that ground is good because we even put an extra ground strap there next to the factory one. Yes i did just replace the frame and this is the last bug i need to work out. I'm guessing the ebcm stands for the "body control module"? I've never heard it called the EBCM before, always just BCM? I don't have a problem replacing parts as the insurance company is paying for it anyways, i just need my damn truck back! Do you have a copy or know where i can print out a copy of this tech bulletin? I can replace the ebcm if needed, but i'll need some sort of proof it is bad so my insurance will pay.

Last edited by Holty; 08-08-2007 at 07:51 AM.
Old 08-08-2007, 06:59 AM
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ALSO, would this code have anything to do with my ABS system not working? I need to confirm if i have an ABS problem AND and BCM issue or is this BCM code directly related to the ABS problems?

Last edited by Holty; 08-08-2007 at 07:55 AM.
Old 08-08-2007, 11:01 AM
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Holty,

It stands for electronic brake control module. Yes that is why your abs is acting up. I will try to get the bulletin for you. Do you want the flow chart too?
Old 08-08-2007, 11:06 AM
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Here is the flow chart


DTC C0265 or C0266 and C065 or C066
Circuit Description
The ABS relay supplies battery voltage to 6 valve solenoids. The electronic brake control module (EBCM) microprocessor applies the grounds needed to activate each solenoid. The low side of each solenoid coil has a feedback circuit to the EBCM microprocessor. When a solenoid is commanded OFF, the feedback voltage is high. When a solenoid is commanded ON, the feedback voltage is low.

Conditions for Running the DTC
The ignition is ON.
The vehicle speed is greater than 6 km/h (4 mph).
Conditions for Setting the DTC
• The EBCM detects an internal malfunction

• Low system voltage

• Open ground at the EBCM

Action Taken When the DTC Sets
C0265
If equipped, the following actions occur:

The EBCM disables the DRP/ABS.
The ABS indicator turns ON.
The brake warning indicator turns ON.
C0266
If equipped, the following actions occur:

The EBCM disables the ABS.
The ABS indicator turns ON.
Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.

Diagnostic Aids
Important: Whenever the EBCM is replaced for DTC C0265 or C0266, the ABS pump motor and motor circuitry must be tested for the proper resistance. Refer to steps 7 and 8 in the diagnostic table below for testing procedures and resistance values.

Check ground G110 for an open or a high resistance.

Check the EBCM power supply for an intermittent open.

C0265
Thoroughly inspect connections and circuitry that may cause an intermittent malfunction. Refer to Testing for Intermittent Conditions and Poor Connections , Testing for Electrical Intermittents , Connector Repairs and to Wiring Repairs in Wiring Systems.

C0266
Replace the EBCM if DTC C0266 continues to set intermittently.

Test Description
The numbers below refer to the step numbers on the diagnostic table.

This step tests if the battery positive voltage circuit can supply adequate power to the system relay.

A shorted ABS pump motor or shorted motor circuitry may damage the contacts within the system relay. Follow this step to prevent damage to a replacement EBCM.

Step
Action
Values
Yes
No

Schematic Reference: ABS Schematics

Connector End View Reference: ABS Connector End Views

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

2
Use a scan tool in order to clear the DTCs.
Use the scan tool in order to perform an ABS Function Test.
Does DTC C0266 set?
--
Go to Step 7
Go to Step 3

3
Does DTC C0265 set?
--
Go to Step 4
Go to Diagnostic Aids

4
Turn OFF the ignition.
Disconnect from the EBCM, the harness connector containing the battery positive voltage circuit.
Connect a test lamp between the battery positive voltage circuit and a good ground.
Does the test lamp illuminate?
--
Go to Step 6
Go to Step 5

5
Repair the open in the battery positive voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?
--
Go to Step 11
--

6
Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 11
Go to Step 7

7

Important
It may be necessary to separate the EBCM from the BPMV to gain access to the pump motor pigtail connector. If so, refer to Electronic Brake Control Module (EBCM) Replacement .


Disconnect from the EBCM, the ABS pump motor pigtail connector.
Use a DMM in order to measure the resistance across the ABS pump motor.
Does the resistance measure within the specified range?
0.3-1.0 ohms
Go to Step 8
Go to Step 10

8
Use a DMM in order to measure the resistance between the high side of the pump motor and a good ground.

Does the resistance measure less than the specified value?
0L
Go to Step 10
Go to Step 9

9

Important
Use the scan tool in order to perform the Tire Size Calibration procedure and the Trim Level Calibration procedure, if applicable.


Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Did you complete the replacement?
--
Go to Step 11
--

10

Important
Use the scan tool in order to perform the Tire Size Calibration procedure and the Trim Level Calibration procedure, if applicable.


Replace the EBCM and the BPMV. Refer to Electronic Brake Control Module (EBCM) Replacement and Brake Pressure Modulator Valve (BPMV) Replacement .

Did you complete the replacements?
--
Go to Step 11
--

11
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK



--------------------------------------------------------------------------------
Old 08-08-2007, 11:08 AM
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here is bulletin,


Subject: ABS Light On, DTCs C0265, C0201, U1041 Set and/or Loss of Communication with Brake Moduel (Reground EBCM Ground) #04-05-25-002D - (06/14/2007)



Models: 2004-2007 Buick Rainier

2002-2006 Cadillac Escalade, Escalade EXT

2003-2006 Cadillac Escalade ESV

1999-2007 Chevrolet Silverado Classic

2000-2006 Chevrolet Suburban, Tahoe

2002-2006 Chevrolet Avalanche

2002-2007 Chevrolet TrailBlazer, TrailBlazer EXT

2003-2006 Chevolet SSR

1999-2007 GMC Sierra Classic

2000-2006 GMC Yukon, Yukon Denali, Yukon XL

2002-2007 GMC Envoy, Envoy XL, Sierra Denali Classic

2004-2005 GMC Envoy XUV

2002-2004 Oldsmobile Bravada




--------------------------------------------------------------------------------

This bulletin is being revised to update model years. Please discard Corporate Bulletin Number 04-05-25-002C (Section 05 -- Brakes).


--------------------------------------------------------------------------------

Condition
Some customers may comment that the ABS light is on. Upon further inspection, DTCs C0265 and C0201 may be set in the brake module. It is also possible for DTC U1041 to set in other modules. There may also be a loss of communication with the brake module.

Cause
A poor connection at the EBCM ground is causing unnecessary replacements of brake modules.

Important: The EBCM Ground is different for each application. Refer to the list below for the proper ground reference:

• Midsize Utilities = Ground 304

• SSR = Ground 400

• Fullsize Trucks and Utilities = Ground 110


Correction
DO NOT REPLACE THE BRAKE MODULE.

Perform the following steps to improve the connection of the EBCM Ground:

Remove the EBCM Ground. The EBCM Ground is located on the frame beneath the driver's side door. If multiple grounds are found in this location, the EBCM ground can be identified as the heavy (12-gauge) wire.
Clean the area, front and back, using a Whiz Wheel®.
Install the ground, then the washer and then the bolt to the frame.
Important: It is important to use the bolts, washers and nuts specified in this bulletin. These parts have been identified due to their conductive finish.

Install a washer and nut to the back side of the frame.
Tighten
Tighten the nut to 9 N·m (79 lb in).

Cover the front and back side of the repair area using Rubberized Undercoating.
An additional check can be made to ensure a good connection for the Battery Cable to Frame ground. It is possible for this ground to cause similar symptoms with the ABS as described above.

Parts Information
FULL-SIZE TRUCKS, SUVs AND H2

Part Number
Description

11588564
Bolt

15650962
Washer

15672934
Nut

12378398

(in Canada, 10952414)
Rubberized Undercoating -- Paintable

MIDSIZE SUVs

Part Number
Description

11517555
Bolt

15650961
Washer

11503749
Nut

12378398

(in Canada, 10952414)
Rubberized Undercoating -- Paintable


Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

N9502
Ground Repair - EBCM Ground
0.2 hr
Old 08-08-2007, 11:54 AM
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Where is the actual EBCM located if i need to replace it?
Old 08-08-2007, 11:57 AM
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Oh, and THANKS for the help!
Old 08-08-2007, 05:02 PM
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It is up under the truck, on the drivers side. Its on top of the block under the truck that is next to your front driveshaft, with all the brake lines going to it. I hope that helps not sure how to explain it. Maybe some one could take a pic of it and post it up... no problem!!!


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