Circuit/System Testing

Ignition OFF, disconnect the harness connector at the S126 Ride Control Switch.
Verify a test lamp illuminates between terminal 4 and B+.
- If the test lamp does not illuminate
  Repair the open or high resistance on circuit 1850 or the ground point for circuit 1850.
- Go to next step: If the test lamp illuminates
Connect the harness connector at the S126 Ride Control Switch.
Disconnect the X2 harness connector at the K9 Body Control Module.
Test for infinite resistance between terminal 8 and ground.
- If less than infinite resistance
1. Test circuit 2202 for a short to ground.
  - If a short to ground is found, repair the fault on circuit 1850.
  - Go to next step: If a short to ground is not found
2. Replace the S126 Ride Control Switch.
- Go to next step: If infinite resistance
Test for less than infinite resistance between terminal 8 and ground while pressing and holding the S126 Ride Control Switch.
- Go to next step: If infinite resistance
1. Test circuit 1850 for an open/high resistance.
  - If an open/high resistance is found, repair the fault on circuit 1850.
  - Go to next step: If an open/high resistance is not found
2. Replace the S126 Ride Control Switch.
- If less than infinite resistance
Replace the K9 Body Control Module.