Hummer H2. Manual - part 230

z

The PCM detects a TCC brake transition.  

z

The PCM does not detect a stop lamp switch transition.  

Action Taken When the DTC Sets 

z

The PCM sets the stop lamp switch status to released.  

z

The PCM disables the operation of the cruise control system.  

Conditions for Clearing the DTC 

z

A history DTC will clear after 40 malfunction free warm-up cycles.  

z

The PCM receives a clear code command from the scan tool.  

Diagnostic Aids 

Refer to Exterior Lighting Systems Description and Operation in Lighting Systems in order to avoid a 
misdiagnosis. 

For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Wiring 
Systems. 

DTC P1574 

Step

Action

Yes

No

Schematic Reference :Cruise Control Schematics 
Connector End View Reference: Cruise Control Connector End Views

1

Did you perform the Cruise Control Diagnostic System Check? Go to 

Step 2

Go to Diagnostic System 

Check - Cruise Control

2

1. Install a scan tool.  

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

3. Depress the brake pedal.  

4. With the scan tool, observe the Stoplamp Pedal Switch 

parameter in the PCM Cruise Control Data list.  

Does the Stoplamp Pedal Switch parameter display Released?

Go to 

Step 3

Go to Diagnostic Aids

3

Do the stop lamps operate properly?

Go to 

Step 4

Go to Stop Lamps 

Inoperative in Lighting 

Systems

4

Repair the open or the high resistance in the stop lamp switch 
signal circuit. Refer to Circuit Testing and to Wiring Repairs
in Wiring Systems. 
Did you complete the repair?

Go to 

Step 5

-

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

2. Operate the vehicle within the conditions for running the 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Cruise Control - Hummer H2

  

SYMPTOMS - CRUISE CONTROL 

Visual/Physical Inspection 

or  

z

Inspect for aftermarket devices which could affect the operation of the Cruise Control System. Refer to 
Checking Aftermarket Accessories in Wiring Systems.  

z

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

Intermittent 

or  

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 Cruise Control Inoperative/Malfunctioning in order to diagnose a symptom. 

CRUISE CONTROL INOPERATIVE/MALFUNCTIONING 

Diagnostic Aids 

Perform the following in order to avoid a misdiagnosis: 

z

Inspect for proper operation of the brake lamps. Refer to Exterior Lighting Systems Description and 
Operation in Lighting Systems.  

z

EMI on the vehicle speed sensor signal circuit may cause erratic cruise control operation. 

5

DTC.  

Does the DTC reset?

Go to 

Step 2

System OK

IMPORTANT: Perform theDiagnostic System Check - Cruise Control before using the 

Symptom Tables in order to verify that all of the following are true: 

z

There are no DTCs set.  

z

The control modules can communicate via the serial data link.  

 
Review the system description and operation in order to familiarize yourself 
with the system functions. Refer to Cruise Control Description and Operation .

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Cruise Control - Hummer H2

  

For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Wiring 
Systems. 

Conditions for Enabling Cruise Control 

z

The vehicle speed is greater than 40 km/h (25 mph).  

z

The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.  

z

The system voltage is within 9 volts and 16 volts.  

Test description 

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

8: This step tests 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.  

9: This step tests the cruise control set/coast switch signal circuit for an open or for a high resistance.  

10: This step tests the cruise control resume/accel switch signal circuit for an open or for a high 
resistance.  

11: This step tests the ignition 3 voltage circuit for an open, for a short to ground, or for a high resistance. 

29: DTCs will set in the PCM when you perform this table.  

Cruise Control Inoperative/Malfunctioning 

Step

Action

Yes

No

Schematic Reference :Cruise Control Schematics 
Connector End View Reference:Cruise Control Connector End Views and Powertrain Control 
Module (PCM) Connector End Views in Engine Controls- 4.8L, 5.3L, and 6.0L

1

Did you perform the Diagnostic System Check - Cruise 
Control?

Go to Step 2

Go to Diagnostic 

System Check - 

Cruise Control

2

1. Install a scan tool.  

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

3. Turn the cruise control On/Off switch OFF.  

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

parameter in the powertrain control module (PCM) 
Cruise Control Data list.  

Does the Cruise On/Off Switch parameter display Off?

Go to Step 4

Go to Step 3

3

1. Turn OFF the ignition.  

2. Disconnect C4 of the multifunction switch.  

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

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

parameter.  

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Cruise Control - Hummer H2

  

Does the Cruise On/Off Switch parameter display Off?

Go to Step 

22

Go to Step 13

4

1. Turn the cruise control On/Off switch ON.  

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

parameter.  

Does the Cruise On/Off Switch parameter display On?

Go to Step 5

Go to Step 11

5

1. With the scan tool, observe the Cruise Set/Coast Switch 

parameter in the PCM Cruise Control Data list.  

2. Turn the cruise control On/Off switch ON.  

3. Press and hold the cruise control Set/Coast button.  

Does the Cruise Set/Coast Switch parameter Display On?

Go to Step 6

Go to Step 9

6

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

Switch parameter in the PCM Cruise Control Data list.  

2. Press and hold the Resume/Accel switch.  

Does the Cruise Resume/Accel. Switch parameter Display On? Go to Step 7

Go to Step 10

7

Do the stop lamps operate properly?

Go to Step 8

Go to Stop Lamps 

Inoperative in 

Lighting Systems

8

1. With the scan tool, observe the Stoplamp Pedal Switch 

parameter in the PCM Cruise Control Data list.  

2. Depress and hold the brake pedal.  

Does the Stoplamp Pedal Switch parameter Display Applied?

Go to 

Diagnostic 

Aids

Go to Step 21

9

1. Turn OFF the ignition.  

2. Disconnect C4 of the multifunction switch.  

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

4. Connect a 3 ampere fused jumper between the cruise 

control set/coast switch signal circuit and the ignition 3 
voltage circuit.  

5. With the scan tool, observe the Cruise Set/Coast Switch 

parameter.  

Does the Cruise Set/Coast Switch parameter Display On?

Go to Step 

22

Go to Step 19

10

1. Turn OFF the ignition.  

2. Disconnect C4 of the multifunction switch.  

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

4. Connect a 3 ampere fused jumper between the cruise 

control resume/accel switch signal circuit and the ignition 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Cruise Control - Hummer H2