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Home >> GMC >> 2006 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 16 (Automatic Transmission - 4L60-E/4L65-E/4L70-E - Service, Diagnosis & Troubleshooting) >> Tow/Haul Switch/Indicator Always On or Inoperative >> Test Description

Test Description

WARNING: This page is about a different variant/trim than selected.

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

  1. 2:  This step tests for a faulty tow/haul switch.
  2. 3:  This step tests for voltage input from the BCM to the tow/haul switch.
  3. 6:  This step tests for ground integrity.
Tow/Haul Switch/Indicator Always On or Inoperative

Step Action Values Yes No
1
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Cycle the tow/haul switch while observing Tow/Haul Mode on the scan tool.
Does the scan tool display Active when the switch is first pressed, and then Inactive when the switch is pressed again?
- Go to Control Module References Go to Step 2 
  1. Remove the connector from the tow/haul switch.
  2. Using the J 35616  GM terminal test kit, install a fused jumper wire from the tow/haul switch signal and ground circuits of the tow/haul switch connector.
Does the scan tool Tow/Haul Mode indicate a status change?
- Go to Step 7  Go to Step 3 
Using the DMM and the J 35616  , measure the voltage at the tow/haul switch signal circuit of the tow/haul switch connector.
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).
Is ignition voltage measured?
- 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
Test the ground 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
7 Replace the tow/haul switch.
Refer to Shift Lever Replacement (With Tow/Haul Switch) .
Did you complete the replacement?
- Go to Step 9  -
8 Replace the BCM.
Refer to Control Module References .
Did you find and correct the condition?
- Go to Step 9  -
9 After the repair is complete, observe Tow/Haul Mode 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