Headlamp Switch Input Open-BCM

HEADLAMP SWITCH INPUT OPEN-BCM

For a complete wiring diagram Consult Diagrams/Electrical

Diagnostic Test

1. CONDITION PRESENT
Turn the ignition on.
With the scan tool, clear all BCM DTC's.
Turn the headlamps to the ON position.
With the scan tool, read DTCs.
Does the scan tool display HEADLAMP SWITCH INPUT OPEN?

Yes

- Go To2

No

- Go To5

2. HEADLAMP SWITCH OPEN

Turn the ignition off.
Disconnect the Headlamp Switch harness connector.
Connect a jumper wire between the (L307) Headlamp Switch MUX circuit and the (L900) Headlamp Switch MUX Return circuit in the Headlamp Switch harness connector.
Turn the ignition on.
With the scan tool, select Body, Body Controller and read the Headlamp Switch volts.
Does the scan tool Headlamp Switch Sensor voltage read less than 0.5 Volts?

Yes

- Replace the Headlamp Switch.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test

No

- Go To3

3. (L307) HEADLAMP SWITCH MUX CIRCUIT OPEN

Turn the ignition off to the lock position.
Disconnect the Body Control Module C5 harness connector.
Disconnect the Headlamp Switch harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the (L900) Headlamp Switch MUX Return circuit from the Body Control Module connector to the Headlamp Switch harness connector.
Is the resistance above 5.0 ohms?

Yes

- Repair the (L900) Headlamp Switch MUX Return circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test

No

- Replace the Body Control Module.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test

5. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle the wiring while checking for shorts and open circuits.
Were there any problems found?

Yes

- Repair as necessary.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test

No

- Test Complete.