Automatic Headlamps

NOTE:

Be certain that the headlamps can be turned ON and OFF manually before attempting to diagnose and repair the Automatic Headlamps. If not, diagnose and repair those problems before attempting to repair the Automatic Headlamps.

NOTE:

The Automatic Headlamp switch is integral to the left multi-function switch/Steering Control Module (SCM), which communicates with the ElectroMechanical Instrument Cluster (EMIC)/Cab Compartment Node (CCN) over the Local Interface Network (LIN) data bus. Before performing any of the following tests, determine whether the other functions of the left multi-function switch/SCM are operational. If the other left multi-function switch/SCM functions are ineffective, diagnose and repair that problem before attempting to repair the Automatic Headlamps.

CONDITION	POSSIBLE CAUSES	CORRECTION
HEADLAMPS DO NOT ILLUMINATE OR EXTINGUISH AUTOMATICALLY	1. AUTO position not selected with the control knob of the left multi-function switch.	1. Select the AUTO position with the control knob of the left multi-function switch.
	2. Engine not running.	2. Start the engine.
	3. Ineffective automatic headlamp (sun) sensor circuits.	3. Check the automatic headlamp (sun) sensor circuits between the sensor and the Automatic Temperature Control (ATC) control head for opens or shorts. Repair the open or shorted circuits if required.
	4. Ineffective automatic headlamp (sun) sensor.	4. Use a diagnostic scan tool to test automatic headlamp (sun) sensor operation. Refer to the appropriate diagnostic information.
	5. Ineffective ATC control head inputs or outputs.	5. Use a diagnostic scan tool to test the ATC control head inputs and outputs. Refer to the appropriate diagnostic information.
	6. Ineffective ElectroMechanical Instrument Cluster (EMIC) (also known as the Cabin Compartment Node/CCN) inputs or outputs.	6. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.
	7. Ineffective TIPM inputs or outputs.	7. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.