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Home >> Jeep >> 2010 >> Commander Limited, RWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Front Control Module (FCM) - Electrical Diagnostics >> DTC Troubleshooting >> B1643-Rear Left Turn Control Circuit Low >> Diagnostic Test
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Diagnostic Test

  1. INTERMITTENT CONDITION 
    1. Turn the ignition on.
    2. Using the scan tool, erase all FCM DTCs.
    3. Turn the Left Turn Signals on.
    4. Using the scan tool, read DTCs.

      Does the scan tool display: B1643-REAR LEFT TURN CONTROL CIRCUIT LOW?

      Yes 

      • Go to step  2

      No 

  2. CHECK (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT IN BODY HARNESS FOR A SHORT TO GROUND 
    Fig 1: Checking Left Rear Turn Signal Control Circuit In Body Harness For A Short To Ground
    GC0120095Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the IPM C2 connector.
    3. Disconnect the Left Rear Turn Stop Tail Lamp connector.
    4. Measure the resistance of the (L63) Left Rear Turn Signal Control circuit between ground and the IPM C2 connector.

      Is the resistance below 5.0 Ohms?

      Yes 

      No 

      • Go to step  3
  3. CHECK (L63) LEFT REAR TURN SIGNAL CONTROL CIRCUIT IN IPM FOR A SHORT TO GROUND 
    Fig 2: Checking Left Rear Turn Signal Control Circuit In IPM For A Short To Ground
    GC0120096Courtesy of CHRYSLER LLC
    1. Disconnect the Front Control Module (FCM) from the IPM 49-way connector.
    2. Measure the resistance of the (L63) Left Rear Turn Signal Control circuit between ground and the IPM 49-way connector.

      Is the resistance below 5.0 Ohms?

      Yes 

      No