FixVault

Test 63A - Diagnosing Parking Lamp Switch

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION  . For wiring diagrams, see appropriate article in ENGINE PERFORMANCE:
  1. Turn ignition off. Disconnect headlamp switch connector. Disconnect Body Control Module (BCM) connectors. Using scan tool in ohmmeter mode, check resistance of headlamp switch 8-pin connector terminal No. 5 (Orange/Dark Blue wire). If resistance is less than 5 ohms, repair short to ground in Orange/Dark Blue wire. If resistance is more than 5 ohms, go to next step.
  2. Using an external ohmmeter, check resistance of Orange/Dark Blue wire between headlamp switch connector terminal No. 5 and BCM Bone connector terminal No. 4. If resistance is more than 5 ohms, repair open Orange/Dark Blue wire. If resistance is less than 5 ohms, go to next step.
  3. Using scan tool in ohmmeter mode, check resistance of headlamp switch 8-pin connector terminal No. 2 (Black wire). If resistance is more than 5 ohms, repair open Black wire. If resistance is less than 5 ohms, go to next step.
  4. Using an external ohmmeter, check resistance between parking lamp/headlamp switch terminals No. 2 and No. 5. See Fig 1 . Slowly rotate dimmer switch from low to high. If resistance does not change from more than 9000 ohms to less than 2000 ohms, replace parking lamp/headlamp switch. If resistance changes from more than 9000 ohms to less than 2000 ohms, replace BCM.
Fig 1: Testing Parking Lamp/Headlamp Switch
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