Diagnostic Test

WARNING: This page is about a different car, the 2016 Jeep Wrangler and 2015 Jeep Wrangler. However, it is still accessible from the selected car via links, so may be relevant.

TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all DTCs
3. Turn on the Left Turn Signal.
4. With the scan tool, read DTCs.
  Does the scan tool display active: B166C-LEFT TRAILER TOW LAMP CONTROL CIRCUIT HIGH?
  
  Yes
  - Go To 2
  No
  - The condition that caused this symptom is currently not present. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals. Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
(L673) LEFT TRAILER TOW LAMP CONTROL CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the TIPM C6 harness connector.
3. Disconnect the Left Trailer Tow Lamp harness connectors.
4. Measure the resistance of the (L673) Left Trailer Tow Lamp Control circuit between the Left Trailer Tow Lamp harness connectors and the TIPM C6 harness connector.
  Does the Ohm meter read open circuit?
  
  Yes
  - Repair the (L673) Left Trailer Tow Lamp Control circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 3
(L673) LEFT TRAILER TOW LAMP CONTROL CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage on the (L673) Left Trailer Tow Lamp Control circuit.
  Is there any voltage present?
  
  Yes
  - Repair the (L673) Left Trailer Tow Lamp Control circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace the Totally Integrated Power Module (TIPM) in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .