Diagnostic Test

INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all Front Control Module (FCM) DTCs.
3. Actuate the Trailer Tow Lamps.
4. With the scan tool read the DTCs.
  Does the scan tool read: B1670-RIGHT TRAILER TOW LAMP CONTROL CIRCUIT HIGH?
  
  Yes
  - Go to step 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. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
TRAILER TOW RELAY
1. Turn the ignition off.
2. Remove and install a known good relay in place of the Right Trailer Tow Relay.
  Do the Trailer Tow Lamps operate normally?
  
  Yes
  - Replace the Right Trailer Tow Relay in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Go to step 3
FRONT CONTROL MODULE (FCM)

Fig 1: Checking Right Trailer Tow Relay Output Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Remove the Right Trailer Tow Relay from the PDC.
3. Disconnect the 49 way FCM IPM harness connector.
4. Measure the voltage of the (L656) Right Trailer Tow Relay Output circuit and ground.
  Is the voltage above 1.0 volt?
  
  Yes
  - Replace the Integrated Power Module (IPM) in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Replace the Front Control Module (FCM) in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .