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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 >> B1668-Reverse Lamp Control Circuit High >> Diagnostic Test
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Diagnostic Test

  1. TEST FOR INTERMITTENT CONDITION 
    1. Turn the ignition on.
    2. Clear all FCM DTC's.
    3. Shift the transmission into reverse.
    4. With the scan tool, read DTC's.

      Does the scan tool read: B1668-REVERSE LAMP CONTROL CIRCUIT HIGH?

      Yes 

      • Go to step  2

      No 

  2. (L1) BACK-UP LAMP FEED CIRCUIT SHORT TO VOLTAGE 
    Fig 1: Checking Back-Up Lamp Feed Circuit Short To Voltage
    GC0120115Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the IPM C2 harness connector.
    3. Turn the ignition on.
    4. Measure the voltage on the (L1) Back-up Lamp Feed circuit.

      Is the voltage greater than 10.0 volts?

      Yes 

      No