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Home >> Jeep >> 2007 >> Liberty Limited, RWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Headlights >> Lighting Systems - Exterior - Electrical Diagnostics >> Lamps/Lighting - Exterior >> DTC Troubleshooting >> Low Beam Headlamps Inoperative >> Diagnostic Test

Diagnostic Test

  1. 1) INTERMITTENT CONDITION 

    Turn the Low Beams on.

    Do the Low Beam Headlamps operate properly? 

    Yes 

    1. The condition is not present at this time. Monitor Scan Tool parameters while wiggling the related wire harness. Refer to any Technical Service Bulletins that may apply. Visually inspect the related wiring harness and connector terminals.
    2. Perform BODY VERIFICATION TEST .

    No 

    1. Go to step  2).
  2. 2) LOW BEAM RELAY 

    Remove the Low Beam Relay from the Junction Block.

    Install a known good relay in place of the Low Beam Relay.

    With the Scan Tool, actuate the Low Beam Relay.

    Do the Headlamps flash while actuating the Low Beam Relay? 

    Yes 

    1. Replace the Low Beam Relay.
    2. Perform BODY VERIFICATION TEST .

    No 

    1. Go to step  3).
  3. 3) OPEN FUSED B(+) CIRCUIT 
    Fig 1: Measuring Voltage Of Fused B(+) Circuit At Low Beam Relay Connector
    GC0046027Courtesy of CHRYSLER LLC

    Remove the Low Beam Relay from the Junction Block.

    Measure the voltage of the Fused B(+) circuit at the Low Beam Relay connector.

    Is the voltage above 10.0 volts? 

    Yes 

    1. Go to step  4).

    No 

    1. Repair the open fused B+ circuit.
    2. Perform BODY VERIFICATION TEST .
  4. 4) LOW BEAM RELAY CONTROL CIRCUIT 
    Fig 2: Measuring Voltage Between Of Fused B(+) Circuit & Low Beam Relay Control Circuit At Low Beam Relay Connector
    GC0046028Courtesy of CHRYSLER LLC

    Remove the BCM from the junction block.

    Connect a jumper wire between the Fused B(+) circuit and the Low Beam Relay Control circuit at the Low Beam Relay connector.

    Measure the voltage of the Low Beam Relay Control circuit to the BCM Junction Block connector.

    Is the voltage above 10.0 volts? 

    Yes 

    1. Go to step  5).

    No 

    1. Repair the Low Beam Relay Control circuit for an open condition.
    2. Perform BODY VERIFICATION TEST .
  5. 5) LOW BEAM HEADLAMP RELAY 

    Disconnect the jumper wire.

    Reinstall the Low Beam Relay in the Junction Block.

    Remove the BCM from the junction block.

    Measure the voltage of the Low Beam Relay Control circuit to the BCM internal connector.

    Is the voltage above 10.0 volts? 

    Yes 

    1. Replace the Body Control Module.
    2. Perform BODY VERIFICATION TEST .

    No 

    1. Replace the Low Beam Relay.
    2. Perform BODY VERIFICATION TEST .