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Hummer H2. Manual - part 231

3 voltage circuit.

5. With the scan tool, observe the Cruise Resume/Accel.

Switch parameter.

Does the Cruise Resume/Accel. Switch parameter Display On?

Go to Step

Go to Step 20

1. Turn OFF the ignition.

2. Disconnect C4 of the multifunction switch.

3. Turn ON the ignition, with the engine OFF.

4. Connect a test lamp between the ignition 3 voltage circuit

and a good ground.

Does the test lamp illuminate?

Go to Step

Go to Step 15

1. Connect a 3 ampere fused jumper between the ignition 3

voltage circuit and the cruise control on switch signal
circuit.

2. With the scan tool, observe the Cruise On/Off Switch

parameter.

Does the Cruise On/Off Switch parameter display On?

Go to Step

Go to Step 18

Test the cruise control on switch signal circuit for a short to
voltage. Refer to Circuit Testing and to Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to Step

Go to Step 14

1. Turn OFF the ignition.

2. Disconnect C1 of the TAC module.

3. Turn ON the ignition, with the engine OFF.

4. With the scan tool, observe the Cruise On/Off Switch

parameter.

Does the Cruise On/Off Switch parameter display On?

Go to Step

Go to Step 23

Test the cruise control set/coast switch signal circuit for a short
to ground. Refer to Circuit Testing and to Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to Step

Go to Step 16

Test the cruise control resume/accel switch signal circuit for a
short to ground. Refer to Circuit Testing and to Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step

Go to Step 17

Test the cruise control on switch signal circuit for a short to
ground. Refer to Circuit Testing and to Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

Go to Step

Go to Step 25

Test the cruise control on switch signal circuit for the

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cruise Control - Hummer H2

following:

An open

A high resistance

A short to ground

Refer to Circuit Testing and to Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to Step

Go to Step 23

Test the cruise control set/coast switch signal circuit for the
following:

An open

A high resistance

A short to ground

Refer to Circuit Testing and to Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to Step

Go to Step 23

Test the cruise control resume/accel switch signal circuit for the
following:

An open

A high resistance

A short to ground

Refer to Circuit Testing and to Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to Step

Go to Step 23

Test the CHMSL supply voltage/stop lamp supply voltage
circuit for an open or for a high resistance between the stop
lamp switch and the TAC module. Refer to Circuit Testing
and to Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step

Go to Step 23

Inspect for poor connections at the harness connector of the
cruise control switch. Refer to Testing for Intermittent
Conditions and Poor Connections and to Connector Repairs
in Wiring Systems.
Did you find and correct the condition?

Go to Step

Go to Step 26

Inspect for poor connections at the harness connector of the
TAC module. Refer to Testing for Intermittent Conditions

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cruise Control - Hummer H2

DESCRIPTION AND OPERATION

CRUISE CONTROL DESCRIPTION AND OPERATION

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions
at vehicle speeds above 40 km/h (25 mph). Steep grades may cause variations in the selected vehicle speeds.

The following are the main components of the Cruise Control System:

The accelerator pedal

The powertrain control module (PCM)

The on/off switch

The resume/accel switch

and Poor Connections and to Connector Repairs in Wiring
Systems.
Did you find and correct the condition?

Go to Step

Go to Step 27

Inspect for poor connections at the harness connector of the
PCM. Refer to Testing for Intermittent Conditions and Poor
Connections and to Connector Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step

Go to Step 28

Repair the open, the high resistance, or the short to ground in
the Ignition 3 voltage circuit. Refer to Circuit Testing and to
Wiring Repairs in Wiring Systems.
Did you complete the repair?

Go to Step

Replace the multifunction switch. Refer to Multifunction,
Turn Signal Switch Replacement in Steering Wheel and
Column.
Did you complete the replacement?

Go to Step

Replace the TAC module. Refer to Throttle Actuator Control
(TAC) Module Replacement in Engine Controls- 4.8L, 5.3L,
and 6.0L.
Did you complete the replacement?

Go to Step

Replace the PCM. Refer to Powertrain Control Module
(PCM) Replacement in Engine Controls- 4.8L, 5.3L, and
6.0L.Did you complete the replacement?

IMPORTANT:

Program the replacement PCM.

Go to Step

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

2. Operate the vehicle within the conditions for cruise

control operation.

Does the cruise control system operate properly?

System OK

Go to Step 2

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cruise Control - Hummer H2

The set/coast switch

The torque converter clutch (TCC)/brake switch

The stop lamp switch

The throttle actuator control (TAC) module

The vehicle speed sensor (VSS)

Cruise Control Engaged

The throttle actuator control (TAC) module monitors the signal circuits of the following cruise control switches:

On/off

Resume/accel

Set/coast

The powertrain control module (PCM) will engage and adjust vehicle speed based on the information received
from the TAC module via the UART serial data link. For further information on the TAC system, refer to
Throttle Actuator Control (TAC) System Description in Engine Controls - 4.8L, 5.3L, and 6.0L.

The cruise control switches are located on the multifunction/turn signal lever.

Ignition positive voltage is supplied from the 10 ampere CRUISE fuse to the cruise control switch via the
ignition 3 voltage circuit. When the normally open cruise control on/off switch is turned ON, the switch closes
and the TAC module detects a high signal voltage on the cruise control on switch signal circuit. When the
normally open set/coast switch is pressed, the switch closes and the TAC module detects a high signal voltage
on the cruise control set/coast switch signal circuit. To engage the Cruise Control System, turn the on/off switch
ON and momentarily press the set/coast switch. The TAC module sends a UART message to the PCM, in order
to confirm that the cruise control enable criteria has been met. The TAC module will engage the Cruise Control
System and record the selected vehicle speed. The PCM sends a class 2 message to the instrument panel cluster
in order to illuminate the cruise control indicator. Pressing the accelerator pedal, while the Cruise Control
System is engaged, will allow the driver to override the Cruise Control System in order to accelerate the vehicle
beyond the current set vehicle speed. When the accelerator pedal is released, the vehicle will decelerate and
resume the current set vehicle speed. The driver can also override the current set vehicle speed via the set/coast
switch and the resume/accel switch. When the Cruise Control System is engaged, pressing and holding the
set/coast switch will allow the vehicle to decelerate from the current set vehicle speed without deactivating the
Cruise Control System. When the set/coast switch is released, the TAC module will record the vehicle speed
and maintain the vehicle speed as the new set vehicle speed. When the Cruise Control System is engaged,
momentarily pressing the set/coast switch will allow the vehicle to decelerate at 1.6 km/h (1 mph) increments
for each time that the set/coast is momentarily pressed, with a minimum vehicle speed of 37 km/h (23 mph).
When the normally open resume/accel switch is activated, the switch closes and the TAC module detects a high
signal voltage on the cruise control resume/accel switch signal circuit. Activating and holding the resume/accel
switch, when the Cruise Control System is engaged, will allow the vehicle to accelerate to a greater vehicle
speed than the current set vehicle speed. When the resume/accel switch is released, the TAC module will record
and maintain the vehicle speed as the new set vehicle speed. When the Cruise Control System is engaged,
momentarily activating the resume/accel switch will allow the vehicle to accelerate at 1.6 km/h (1 mph)
increments for each time that the resume/accel switch is momentarily activated, with the maximum acceleration

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Cruise Control - Hummer H2

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