Hummer H2. Manual — part 759

solenoid valve.

LR Outlet Valve Solenoid Inactive

The scan tool displays Active or Inactive. The scan tool displays the commanded state of the LR outlet
solenoid valve.

Pump Motor Relay Command

The scan tool display On/Off. This is the commanded state of the relay.

Rear TCS Isolation Solenoid

The scan tool will display Active/Inactive. This will be the commanded state of the solenoid valve.

Rear TCS Prime Solenoid

The scan tool will display Active/Inactive. This will be the commanded state of the solenoid valve.

RF Inlet Valve Solenoid Inactive

The scan tool displays Active or Inactive. The scan tool displays the commanded state of the RF inlet
solenoid valve.

RF Outlet Valve Solenoid Inactive

The scan tool displays Active or Inactive. The scan tool displays the commanded state of the RF outlet
solenoid valve.

Right Front Wheel Speed

The scan tool displays 0-255 km/h or (0-158 mph). The scan tool displays the actual speed of the right
front wheel.

RR Inlet Valve Solenoid Inactive

The scan tool displays Active or Inactive - The scan tool displays the commanded state of the RR inlet
solenoid valve.

RR Outlet Valve Solenoid Inactive

The scan tool displays Active or Inactive - The scan tool displays the commanded state of the RR outlet
solenoid valve.

Right Rear Wheel Speed

2004 Hummer H2

2004 BRAKES Anti-Lock Brake System - Hummer H2

The scan tool displays 0-255 km/h or (0-158 mph). The scan tool displays the actual speed of the right
rear wheel.

Solenoid Relay Command

The scan tool will display On/Off depending on the state of the relay.

TCS Active

The scan tool will display Off or On. The scan tool displays On if the TCS indicator is currently being
commanded ON.

DIAGNOSTIC TROUBLE CODE (DTC) LIST

Diagnostic Trouble Code (DTC) List

DTC

Description

Module

(s)

DTC
B3626

TC2 Mode Switch

BCM

DTC
C0035

Left Front Wheel Speed Circuit Malfunction

EBCM

DTC
C0036

LF Wheel Speed Circuit Range/Performance

EBCM

DTC
C0040

Right Front Wheel Speed Circuit Malfunction

EBCM

DTC
C0041

Right Front Wheel Speed Sensor Circuit Range/Performance (EBCM)

EBCM

DTC
C0045

Left Rear Wheel Speed Circuit Malfunction

EBCM

DTC
C0046

Left Rear Wheel Speed Sensor Circuit Range/Performance (EBCM)

EBCM

DTC
C0050

Right Rear Wheel Speed Circuit Malfunction

EBCM

DTC
C0051

LF Wheel Speed Sensor Circuit Range/Performance (EBCM)

EBCM

DTC
C0110

Pump Motor Circuit Malfunction

EBCM

DTC
C0121

Valve Relay Circuit Malfunction

EBCM

DTC
C0161

ABS/TCS Brake Switch Circuit Malfunction

EBCM

DTC
C0192

Longitudinal Accelerometer Sensor Circuit Malfunction

EBCM

DTC
C0245

Wheel Speed Sensor Frequency Error

EBCM

2004 Hummer H2

2004 BRAKES Anti-Lock Brake System - Hummer H2

ENHANCED DIAGNOSTICS

History Data

Enhanced diagnostic information is found in the History Data function of the scan tool. Enhanced diagnostic
information provides the service technician with specific malfunction occurrence information.

The scan tool will display the last 3 DTCs to occur, one at a time. The DTC with the most recent occurrence
will be displayed first. Each DTC will include the following:

z

The number of drive cycles since the DTC last occurred.

z

The number of occurrences for the DTC since the scan tool DTC information was last cleared.

The most recent DTC will also display various data parameters with values from the time of the DTC
occurrence.

Diagnostic Strategy

In difficult diagnostic situations use the above information to identify malfunction occurrence trends. Ask
questions such as the following:

z

Did the malfunction only occur once over a large number of drive cycles, indicating an unusual condition
present when it occurred?

z

Does the malfunction occur infrequently over a large number of drive cycles, indicating that special
diagnostic techniques may be required to identify the source of the malfunction?

A malfunction that occurs more frequently increases the odds of finding the cause of the malfunction.

Use the information in order to determine if a DTC is intermittent. Use the information in order to determine if
the DTC has not set for long periods of time due to weather changes or a repair prior to this visit.

DTC B3626

DTC
C0267

Pump Motor Circuit Open/Shorted

EBCM

DTC
C0550

ECU Malfunction - internal write / checksum malfunction

EBCM

DTC
C0896

Electronic Suspension Control (ESC) voltage is outside the normal range of 9 to
15.5 volts

EBCM

DTC
U1000

Class 2 Communication Malfunction

Class 2

DTC
U1300

Class 2 Short to Ground

Class 2

DTC
U1301

Class 2 Short to Battery

Class 2

2004 Hummer H2

2004 BRAKES Anti-Lock Brake System - Hummer H2

Circuit Description

The TC2 mode switch is a momentary-contact switch that can be used to limit the traction control function.
Each time the TC2 mode switch is pressed, the TC2 switch full traction limited status changes. When the TC2
mode switch is released, voltage on the TC2 mode switch signal circuit is approximately 12 volts. When the
TC2 mode switch is pressed, voltage on the TC2 mode switch signal circuit is approximately 0.5 volts.

Conditions for Running the DTC

In order to detect a continuously low or high TC2 mode switch signal:

The ignition is ON.

OR:

In order to detect a continuously pressed TC2 mode switch:

z

The ignition is ON.

z

The engine speed is greater than 450 RPM.

Conditions for Setting the DTC

Either of the following conditions may cause DTC B3626 to set:

z

The TC2 mode switch signal is detected as excessively low or high for 200 milliseconds.

z

The TC2 mode switch is detected as pressed for 60 seconds.

Action Taken When the DTC Sets

z

The EBCM disables the traction assist.

z

The TCS LED switch telltale is disable.

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

Press and release the TC2 mode switch several times while observing the traction LED switch telltale in order
to verify that the TC2 full traction limited status changes each time the switch is pressed and that DTC B3626
does not set. Using the scan tool in order to observe the Mode Switch Pressed or Released status may also be
helpful in diagnosing an intermittent fault within the switch.

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

2004 Hummer H2

2004 BRAKES Anti-Lock Brake System - Hummer H2