Test Step 4 - Check the Sun Sensor

• Reconnect the A/C heater control C1 harness connector.
• Turn the ignition ON.
• Using the scan tool, observe the auto headlamp signal while connecting a jumper wire between the auto headlamps signal circuit and the sensor ground circuit in the sun sensor harness connector.

Does the Auto Headlamp signal change from approximately 5 volts to 0 volts?

Yes

• Replace the sun sensor. Refer to REMOVAL AND INSTALLATION .
• Perform the HVAC Verification Test. Refer to HVAC .

No

• Replace the A/C heater control. Refer to REMOVAL AND INSTALLATION .
• Perform the HVAC Verification Test. Refer to HVAC .