Diagnosis And Testing: Headlamps

WARNING: This page is about a different car, the 2006 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: As part of the exterior lighting failsafe feature, upon ignition ON, all exterior park lamps and the headlamp low beams will illuminate regardless of the headlamp switch position if the CCN cannot detect an input from the headlamp switch, or if there is a loss of data bus communication.

HEADLAMP DIAGNOSIS

CONDITION	POSSIBLE CAUSES	CORRECTION
HEADLAMP DOES NOT ILLUMINATE	1. Ineffective or missing bulb.	1. Test and replace headlamp bulb as required.
	2. Ineffective ground circuit.	2. Test and repair open headlamp ground circuit as required.
	3. Ineffective feed circuit.	3. Test and repair open headlamp low beam or high beam feed circuit as required.
	4. Ineffective switch.	4. Test and replace headlamp switch as required.
	5. Ineffective TIPM inputs or outputs.	5. Use a diagnostic scan tool to test the TIPM inputs and outputs as required. Refer to the appropriate diagnostic information. Check for TIPM DTC's.
HEADLAMP DOES NOT EXTINGUISH	1. Ineffective switch.	1. Test and replace left multi-function switch as required.
	2. Ineffective feed circuit.	2. Test and repair shorted headlamp low beam or high beam feed circuit as required.
	3. Ineffective CCN inputs or outputs.	3. Use a diagnostic scan tool to test the CCN inputs and outputs as required. Refer to the appropriate diagnostic information.
	4. Ineffective TIPM inputs or outputs.	4. Use a diagnostic scan tool to test the TIPM inputs and outputs as required. Refer to the appropriate diagnostic information.
HEADLAMPS ILLUMINATE WITH IGNITION ON AND HEADLAMP SWITCH OFF (FAIL-SAFE OPERATION)	1. Ineffective circuits between headlamp switch and instrument cluster.	1. Test and repair left multi-function switch mux and return circuits as required.
	2. Loss of data bus communication.	2. Use a diagnostic scan tool to test the data bus. Refer to the appropriate diagnostic information.
	3. Ineffective switch.	3. Test and replace the left multi-function switch as required.
	4. Ineffective CCN inputs or outputs.	4. Use a diagnostic scan tool to test the CCN inputs and outputs as required. Refer to the appropriate diagnostic information.
HEADLAMPS WILL NOT SWITCH FROM HIGH TO LOW BEAMS, OR FROM LOW TO HIGH BEAMS	1. Ineffective circuits between left multi-function switch and CCN.	1. Test and repair wash/beam select mux and multi-function switch return circuits as required.
	2. Ineffective switch.	2. Test and replace the left multi-function switch as required.
	3. Ineffective CCN inputs or outputs.	3. Use a diagnostic scan tool to test the CCN inputs and outputs as required. Refer to the appropriate diagnostic information.
	4. Ineffective TIPM inputs or outputs.	4. Use a diagnostic scan tool to test the TIPM inputs and outputs as required. Refer to the appropriate diagnostic information.