Test Description
WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step tests for a faulty tow/haul switch.
- 3: This step tests for voltage input from the BCM to the tow/haul switch.
- 6: This step tests for voltage through the body wiring harness.
- 7: This step tests for ground integrity at the splice pack.
Tow/Haul Switch/Indicator Always On or Inoperative
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| 1 |
|
- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 2 |
| 2 |
|
- | Go to Step 7 | Go to Step 3 |
| 3 | Using the DMM and the J 35616
GM Terminal Test Kit, measure the voltage at the tow/haul switch signal circuit of the I/P wiring harness connector. See Special Tools
. Is ignition voltage measured? |
- | Go to Step 6 | Go to Step 4 |
| 4 | Using the DMM and the J 35616
, measure the voltage at the tow/haul switch signal circuit of the body control module (BCM). See Special Tools
. Does the voltage measure near the specified value? |
10-12 V | Go to Step 5 | Go to Step 8 |
| 5 | Test the signal circuit of the tow/haul switch for an open or shorted condition. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 9 | Go to Testing for Intermittent Conditions and Poor Connections |
| 6 | Test the ground circuit of the tow/haul switch for an open or high resistance condition between the I/P wiring harness connector and ground. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 9 | Go to Testing for Intermittent Conditions and Poor Connections |
| 7 | Replace the tow/haul switch. Refer to Tow/Haul Switch Replacement
. Did you complete the replacement? |
- | Go to Step 9 | - |
| 8 | Replace the BCM. Refer to Control Module References
for replacement, setup and programming. Did you find and correct the condition? |
- | Go to Step 9 | - |
| 9 | After the repair is complete, observe Tow/Haul Mode parameter on the scan tool display, while cycling the tow/haul switch. Does the scan tool display Active when the switch is first pressed, and then Inactive when the switch is pressed again? |
- | System OK | Go to Step 1 |