Circuit/System Testing

Ignition OFF, exterior lamps OFF, disconnect the harness connector at the appropriate component listed below. It may take up to 2 min for all vehicle systems to power down.
- B211A Rear Multifunction Carrier Closed Position Switch
- B211B Rear Multifunction Carrier Open Position Switch
Test for less than 5 Ω between the ground circuit terminal 2 and ground.
- If 5 Ω or greater
1. Ignition OFF.
2. Test for less than 2 Ω in the ground circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, repair the open/high resistance in the ground connection.
- Go to next step: If less than 5 Ω
Ignition ON.
Test for 4.8 - 5.2 V between the signal circuit terminal 1 and ground.
- If less than 4.8 V
1. Ignition OFF, disconnect the X1 harness connector at the K68 Trailer Lighting Control Module.
2. Test for infinite resistance between the signal circuit terminal 1 and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
3. Test for less than 2 Ω in the control circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K68 Trailer Lighting Control Module.
- If greater than 5.2 V
1. Ignition OFF, disconnect the X1 harness connector at the K68 Trailer Lighting Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit terminal 1 and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V, replace the K68 Trailer Lighting Control Module.
- Go to next step: If between 4.8 - 5.2 V
Test or replace the B211 Rear Multifunction Carrier Position Switch.