Diagnosis And Testing - Sun Sensor
Disable the airbag system before attempting any steering wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the negative battery (ground) cable, then wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to take the proper precautions may result in an accidental airbag deployment and possible serious or fatal injury.
The sun sensor assembly is located so that the sun rays will hit the sensors in the same way that it will hit the driver and the passenger. It is important that the area in front of the sun sensor assembly be unobstructed. Check for the following:
- Any items laying on top of the instrument panel are not covering the sun sensor.
- Any stickers on the windshield are not directly in front of the sun sensor.
- Windshield wipers are properly adjusted.
- Defroster grille and sun sensor are properly installed. The sun sensor lens should protrude above the defroster grille.
If the vehicle exhibits a lack of passenger comfort in sunny weather such as in the early afternoon, inspect the position of the sun sensor assembly. The sun sensor lens should protrude above the defroster grille to insure proper operation. If the sun sensor is not properly positioned, perform the following procedure:
- Confirm that the defroster grille is properly installed. If not, repair as required.
- Remove the defroster grille and verify that the sun sensor is properly installed to the instrument panel. Refer to SENSOR, SUN, INSTALLATION .
- Reinstall the defroster grille.
The A/C heater module continually monitors the sun sensor through hard-wired circuits and will store Diagnostic Trouble Codes (DTCs) for any problem it detects. The sun sensor can be tested in the vehicle with a scan tool. Refer to the DIAGNOSTIC CODE INDEX .