B166C

B166C-LEFT TRAILER TOW LAMP CONTROL CIRCUIT HIGH





For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
- With the Trailer Tow Lamps activated.
- Set Condition:
- When the FCM detects a LOW condition.





Diagnostic Test

1. INTERMITTENT CONDITION
Turn the ignition on.
With the Scan Tool, clear all FCM DTC's.
Actuate the Trailer Tow Lamps.
With the Scan Tool read the DTC information.
Does the Scan Tool read: B166C-LEFT TRAILER TOW LAMP CONTROL CIRCUIT HIGH?

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 BODY VERIFICATION TEST Body Verification Test

2. LEFT TRAILER TOW RELAY
Turn the ignition off.
Remove and install a known good relay in place of the Left Trailer Tow Relay.
Do the Trailer Tow Lamps operate normally?

Yes

- Replace the Left Trailer Tow Relay.
- Perform BODY VERIFICATION TEST Body Verification Test

No

- Go To 3


3. FRONT CONTROL MODULE




Turn the ignition off.
Remove the Left Trailer Tow Relay from the MPD.
Remove the FCM from the Module Power Distribution.
Measure the voltage of the (L655) Left Trailer Tow Relay Output circuit and ground.
Is the voltage above 1.0 volts?

Yes

- Replace the Module Power Distribution center.
- Perform BODY VERIFICATION TEST Body Verification Test

No

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