B166B

B166B-LEFT TRAILER TOW LAMP CONTROL CIRCUIT LOW





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
- With the Trailer Tow Lamps activated.
- Set Condition:
- When the Front Control Module (FCM) detects a low condition in the Left Trailer Tow Lamp Relay Control circuit.






1. INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool , clear all FCM DTCs.
3. Turn the Trailer Tow Lamps on.
4. With the scan tool read the DTCs.

Does the Scan Tool read: B166B-LEFT TRAILER TOW LAMP CONTROL CIRCUIT LOW?

Yes

- Go To 2

No

- The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. (L655) LEFT TRAILER TOW BRAKE LAMP RELAY CONTROL CIRCUIT
1. Turn the ignition off.
2. Disconnect the 49 way FCM IPM harness connector.
3. Measure the resistance between ground and the (L655) Left Trailer Tow Brake Lamp Relay Control circuit.

Is the resistance below 5.0 Ohms?

Yes

- Replace the Front Control Module (FCM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair the (L655) Left Trailer Tow Brake Lamp Relay Control circuit for a short to ground condition.
- Perform the BODY VERIFICATION TEST. Body Verification Test.