Hummer H2. Manual - part 765

of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by 
using the following procedure: 

1. Spray the suspected area with a five percent saltwater solution. 

Add two teaspoons of salt to twelve ounces of water to make a five percent saltwater solution. 

2. Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 40 km/h (25 mph) for at 

least 30 seconds.  

3. If the DTC returns, replace the suspected harness.  

z

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

Test Description 

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

2: If DTC C0245 is a history code, this step checks if a specific Wheel Speed Circuit Malfunction DTC is 
set concurrently with DTC C0245.  

7: This step checks if the wheel speed sensor harness is routed in close proximity to the spark plug wires. 

9: In this step, if the scan tool can record any erroneous wheel speed sensor signals, diagnose that sensors 
first.  

DTC C0245 

Step

Action

Yes

No

Schematic Reference: ABS Schematics 
Connector End View Reference:ABS Connector End Views

1

Did you perform the diagnostic system check?

Go to Step 2

Go to 

Diagnostic 

System Check - 

ABS

2

Is the following DTCs set concurrently with a history DTC 
C0245? 

z

DTC C0036  

z

DTC C0041  

z

DTC C0046  

z

DTC C0051  

Go to DTC 
Diagnostic 

Trouble Code 

(DTC) List

Go to Step 3

3

Inspect the WSS for physical damage. 
Is physical damage of the WSS evident?

Go to Step 4

Go to Step 5

4

Replace the WSS. Refer to Wheel Speed Sensor 
Replacement - Front or Wheel Speed Sensor 
Replacement - Rear . 
Is the replacement complete?

Go to Step 14

-

Inspect the wiring harness for physical damage. 

 

2004 Hummer H2 

2004 BRAKES Anti-Lock Brake System - Hummer H2

  

5

Is physical damage of the wiring harness evident?

Go to Step 6

Go to Step 7

6

Repair the wiring harness. Refer to Wiring Repairs and 
Connector Repairs in Wiring Systems. 
Is the replacement complete?

Go to Step 14

-

7

Check for proper routing of the wheel speed sensor harness. 
Check that the wheel speed sensor harness is routed away 
from the spark plug wires. Refer to Harness Routing Views 
in Wiring Systems. 
Is the wheel speed sensor harness properly routed?

Go to Step 9

Go to Step 8

8

Reroute the wheel speed sensor harness away from the spark 
plug wires. 
Is the reroute complete?

Go to Step 14

-

9

1. Install a scan tool.  

2. Turn the ignition switch to the RUN position.  

3. Set the scan tool to Snap Shot Auto Trigger mode and 

monitor the wheel speed sensors.  

4. Carefully drive the vehicle above 12 km/h (8 mph) for 

several minutes  

Did the scan tool trigger on any of the wheel speed sensors?

Go to Step 10

Go to Step 11

10

Note which wheel speed sensor triggered the scan tool. 
Follow the appropriate Wheel Speed Sensor Malfunction 
DTC table for the wheel speed sensor that triggered. Refer to 
Diagnostic Trouble Code (DTC) List . 
Is the repair complete?

Go to Step 14

-

11

1. Reconnect all previously disconnected components.  

2. Using a scan tool clear the DTC.  

3. Remove the scan tool from the DLC.  

4. Carefully drive the vehicle above 12 km/h (8 mph) for 

several minutes.  

Does the DTC reset as a current DTC?

Go to Step 13

Go to Step 12

12

Malfunction is intermittent. Inspect all connectors and 
harnesses for damage that may result in an open or high 
resistance when connected. Refer to Connector Repairs and 
Wiring Repairs in Wiring Systems. 
Is the repair complete?

Go to Step 14

-

13

Replace the EBCM. Refer to Electronic Brake Control 
Module Replacement . 
Is the replacement complete?

Go to Step 14

-

14

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.  

 

2004 Hummer H2 

2004 BRAKES Anti-Lock Brake System - Hummer H2

  

DTC C0550 

Circuit Description 

This DTC identifies a malfunction within the EBCM. 

Conditions for Running the DTC 

The ignition switch is in the ON position. 

Conditions for Setting the DTC 

DTC C0550 is set when an internal EBCM or solenoid malfunction exists. 

Action Taken When the DTC Sets 

If equipped, the following actions occur: 

z

The EBCM disables the ABS/TCS for the duration of the ignition cycle.  

z

A malfunction DTC will set.  

z

The ABS indicator turns on.  

z

The TCS indicator turns on.  

Conditions for Clearing the DTC 

z

The condition for the DTC is no longer present and you used the scan tool Clear DTC function.  

z

The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive 
drive cycles.  

DTC C0550 

Does the DTC reset?

Go to Step 2

System OK

Step

Action

Yes

No

Schematic Reference:ABS Schematics 
Connector End View Reference:ABS Connector End Views

1

Did you perform the Diagnostic System Check?

Go to Step 2

Go to Diagnostic 

System Check - ABS

2

Are any other DTC(s) present besides C0550?

Go to Diagnostic 

Trouble Code (DTC) 

List

Go to Step 3

3

Replace the EBCM. Refer to Electronic Brake 
Control Module Replacement . 
Is the replacement complete?

Go to Step 4

-

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

 

2004 Hummer H2 

2004 BRAKES Anti-Lock Brake System - Hummer H2

  

DTC C0896 

Circuit Description 

The EBCM is required to operate within a specified range of voltage to function properly. During ABS and 
TCS operation, there are current requirements that will cause the voltage to drop. Because of this, voltage is 
monitored out of ABS/TCS control to indicate a good charging system condition, and also during ABS/TCS 
control when voltage may drop significantly. The EBCM also monitors for high voltage conditions which could 
damage the EBCM. 

Conditions for Running the DTC 

z

The ignition switch is ON.  

z

The DTC can be set after system initialization.  

Conditions for Setting the DTC 

z

The EBCM operating voltage falls below 9.4 volts out of ABS/TCS control, or 8.8 volts during ABS/TCS 
control.  

z

The EBCM operating voltage rises above 17.4 volts.  

z

The low voltage or the high voltage is detected for more than 500 milliseconds with the vehicle speed 
above 6 km/h (3.6 mph).  

Action Taken When the DTC Sets 

If equipped, the following actions occur: 

z

A malfunction DTC is stored.  

z

The ABS and the Traction Control indicators are turned on.  

z

The ABS/TCS is disabled.  

z

The Brake warning indicator turns on.  

Conditions for Clearing the DTC 

z

The condition for the DTC is no longer present and the DTC is cleared with a scan tool.  

z

The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC 
is not detected in 100 consecutive drive cycles.  

Diagnostic Aids 

4

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

 

2004 Hummer H2 

2004 BRAKES Anti-Lock Brake System - Hummer H2