Hummer H2. Manual - part 766

It is very important that a thorough inspection of the wiring and connectors be performed. Failure to
carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement
with reappearance of the malfunction.

Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:

{

Backed out terminals

{

Improper mating

{

Broken locks

{

Improperly formed or damaged terminals

{

Poor terminal-to-wiring connections

{

Physical damage to the wiring harness

The following conditions may cause an intermittent malfunction:

{

A poor connection

{

Rubbed-through wire insulation

{

A broken wire inside the insulation

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor
Connections in Wiring Systems for further diagnosis.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

2: This step checks if the voltage is above the maximum of the range.

4: Step 4 checks if the voltage is below the minimum of the range.

6: This step checks for the integrity of the ground circuit.

DTC C0896

Step

Action

Value

(s)

Yes

Schematic Reference: ABS Schematics
Connector End View Reference:ABS Connector End Views or Powertrain Control Module (PCM)
Connector End Views

Did you perform the Diagnostic System Check?

Go to

Step 2

Go to Diagnostic

System Check - ABS

1. Turn all the accessories off.

2. Install a scan tool.

3. Start the engine.

4. Use the scan tool to monitor the battery voltage

while running the engine at approximately 2000
RPM.

Is the monitored battery voltage within the specified

0-17.4

Go to

2004 Hummer H2

2004 BRAKES Anti-Lock Brake System - Hummer H2

range?

Step 4

Go to Step 3

Use a J 39200 to measure the voltage between the
battery positive terminal and ground.
Is the voltage within the specified range?

0-17.4

Go to

Step 5

Go to Symptoms -

Engine Electrical in

Engine Electrical

Continue to monitor the battery voltage with the scan
tool while running the engine at approximately 2000
RPM.
Is the monitored battery voltage within the specified
range?

0-9.4 V

Go to

Step 6

Go to Step 5

1. Turn the ignition switch to the OFF position.

2. Disconnect the scan tool if still connected.

3. Test drive the vehicle above 6 km/h (3.5 mph).

Did DTC C0896 reset?

Go to

Step

Go to Diagnostic

System Check - ABS

1. Turn the ignition switch to the OFF position.

2. Disconnect the EBCM connector.

3. Install the J 39700 with the. See Special Tools

and Equipment . J 39700-530 to the EBCM
harness connector only.

4. Use a J 39200 to measure the resistance between

the J 39700 terminal 15 and a good ground. See
Special Tools and Equipment .

Is the resistance within the specified range?

0-5 ohm

Go to

Step 8

Go to Step 7

Repair open or high resistance in the ground circuit.
Refer to Circuit Testing and Wiring Repairs Wiring
Repairs.
Is the repair complete?

Go to

Step

1. Turn the ignition switch to the RUN position.

2. Use a J 39200 to measure the voltage between

the J 39700 terminal 8 and 15. See Special Tools
and Equipment .

Is the voltage within the specified range?

Above

9.4 V

Go to

Step 9

Go to Symptoms -

Engine Electrical in

Engine Electrical

1. Turn the ignition switch to the OFF position.

2. Reconnect the EBCM connector.

3. Disconnect the scan tool if the scan tool is still

connected.

4. Test drive the vehicle above 6 km/h (3.5 mph).

Did DTC C0896 reset?

Go to

Step

Go to Step 11

Replace the EBCM. Refer to Electronic Brake

Go to

2004 Hummer H2

2004 BRAKES Anti-Lock Brake System - Hummer H2

SYMPTOMS - ANTI-LOCK BRAKE SYSTEM

1. Perform the Diagnostic System Check - ABS before using the Symptom Tables in order to verify that all

of the following are true:

There are no DTCs set.

The control modules can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to ABS

Description and Operation

Visual/Physical Inspection

Inspect for aftermarket devices which could affect the operation of the anti-lock brake system. Refer to
Checking Aftermarket Accessories in Wiring Systems.

Inspect the easily accessible or visible system components for obvious damage or conditions which could
cause the symptom.

Inspect the master cylinder reservoir for the proper brake fluid level.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for
Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

ABS Indicator Always On

ABS Indicator Inoperative

Traction Off Indicator Always On

Traction Off Indicator Inoperative

ABS INDICATOR ALWAYS ON

Control Module Replacement .
Is the repair complete?

Step

1. Use the scan tool in order to clear the DTCs.

2. 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

IMPORTANT: The following steps must be completed before using the symptom tables.

2004 Hummer H2

2004 BRAKES Anti-Lock Brake System - Hummer H2

Circuit Description

The instrument panel cluster (IPC) turns the anti-lock brake system (ABS) indicator ON during the IPC bulb
check for approximately 3 seconds when the ignition switch is turned to the ON position. If the electronic brake
control module (EBCM) sets a diagnostic trouble code (DTC) the EBCM sends the IPC the command to turn
the ABS indicator ON

Diagnostic Aids

Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:

{

Backed out terminals

{

Improper mating

{

Broken locks

{

Improperly formed or damaged terminals

{

Poor terminal-to-wiring connections

{

Physical damage to the wiring harness

The following conditions may cause an intermittent malfunction:

{

A poor connection

{

Rubbed-through wire insulation

{

A broken wire inside the insulation

If an intermittent malfunction exists refer to Inducing Intermittent Fault Conditions in Wiring
Systems.

Test Description

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

2: Checks if the IPC has the ability to turn the ABS indicator OFF or if the EBCM is sending an incorrect
command to turn the ABS indicator ON.

ABS Indicator Always On

Step

Action

Yes

Schematic Reference:ABS Schematics
Connector End View Reference:Instrument Panel, Gauges, and Console Connector End Views

Did you perform the anti-lock brake system (ABS) Diagnostic
System Check?

Go to

Step 2

Go to Diagnostic

System Check - ABS

Using a scan tool in the Instrument Panel Cluster (IPC) Special
Functions attempt to turn OFF the ABS indicator.
Did the ABS indicator turn OFF?

Go to

Step 3

Go to Step 4

Replace the electronic brake control module (EBCM). Refer to

2004 Hummer H2

2004 BRAKES Anti-Lock Brake System - Hummer H2

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