LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 2009 >> Commander Overland, RWD >> Repair and Diagnosis (Single Page) >> Brakes >> Brakes Control Systems >> Front Control Module (FCM) - Electrical Diagnostics >> DTC Troubleshooting >> B166D-Left Trailer Tow Lamp Control Circuit Open >> Diagnostic Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Test

  1. INTEGRATED POWER MODULE 
    1. Turn the ignition off.
    2. Replace the Trailer Tow Left Turn relay with and known good relay.
    3. Using the scan tool, clear all FCM DTCs.
    4. Activate the Left Turn Signal.
    5. Using the scan tool, read the Wiper DTCs.

      Does the scan tool read: B166D-LEFT TRAILER TOW LAMP CONTROL CIRCUIT OPEN?

      Yes 

      No