Circuit/System Testing

Ignition/vehicle OFF, disconnect the harness connector at the S126 Ride Control Switch.
Verify a test lamp illuminates between the low reference terminal 3 and B+.
- If the test lamp does not illuminate
1. Test circuit 1449 for an open/high resistance.
  - If an open/high resistance is found, repair the fault on the circuit.
  - Go to next step: If an open/high resistance is not found.
2. Replace the K9 Body Control Module.
- Go to next step: If the test lamp illuminates
Ignition/vehicle OFF, disconnect the X2 connector at the K9 Body Control Module.
Test for infinite resistance between signal circuit terminal 10 and ground.
- If less than infinite resistance
1. Test circuit 2203 for a short to ground.
  - If a short to ground is found, repair the fault on the circuit.
  - 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
Connect the connector at the S126 Ride Control Switch.
Press and hold the S126 Ride Control Switch.
Test for less than infinite resistance between signal circuit terminal 2203 and ground.
- If infinite resistance
1. Disconnect the connector at the S126 Ride Control Switch.
2. Test the low reference circuit 1449 for an open/high resistance.
  - If an open/high resistance is found, repair the fault on the circuit.
  - Go to next step: If an open/high resistance is not found.
3. Test signal circuit 2203 for an open/high resistance.
  - If an open/high resistance is found, repair the fault on the circuit.
  - Go to next step: If an open/high resistance is not found.
4. Replace the S126 Ride Control Switch.
- Go to next step: If less than infinite resistance
Replace the K9 Body Control Module.