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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 >> B1634-Left Hi Beam Control Circuit High >> Diagnostic Test
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Diagnostic Test

  1. INTERMITTENT CONDITION 
    1. Turn the ignition on.
    2. With the scan tool, clear all FCM DTCs.
    3. Turn the Headlamps on.
    4. With the scan tool, read the DTC information.

      Does the scan tool display B1634-LEFT HI BEAM CONTROL CIRCUIT HIGH?

      Yes 

      • Go to step  2

      No 

      • Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
      • Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  2. LEFT HIGH BEAM BULB 
    1. Turn the ignition off.
    2. Inspect the Left High Beam Bulb Assembly.

      Is the inoperative bulb OK?

      Yes 

      • Go to step  3

      No 

  3. (L33) HIGH BEAM CONTROL CIRCUIT OPEN 
    Fig 1: Checking High Beam Control Circuit
    GC0120081Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the FCM C2 harness connector.
    3. Measure the resistance of the (L33) High Beam Control circuit.

      Is the resistance above 5.0 Ohms?

      Yes 

      No