Manual Temperature Control

B160F - Ambient Light Sensor Input Circuit Performance

For a complete wiring diagram, refer to.

• When Monitored: With the ignition on.

• Set Condition: If the ambient light sensor input is out of range.






• This DTC must be active for the results of this test to be valid. Do not perform this test if this DTC is stored.

Test Step 1 - Check Auto Headlamps Signal Circuit for an Open

• Turn the ignition OFF.

• Disconnect the A/C heater control C1 harness connector.

• Disconnect the sun sensor harness connector.

• Measure the resistance of the auto headlamps signal circuit between the sun sensor harness connector and the A/C heater control C1 harness connector.

Is the resistance less than 5 ohms?

Yes

• Go to Test Step 2 => [ Test Step 2 - Check Auto Headlamps Signal Circuit for a Short to
Ground ]
No

• Repair the auto headlamps signal circuit for an open.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 2 - Check Auto Headlamps Signal Circuit for a Short to Ground

• Measure the resistance between ground and the auto headlamps signal circuit in the A/C heater control C1 harness connector.

Is the resistance more than 10k ohms?

Yes

• Go to Test Step 3 => [ Test Step 3 - Check Sensor Ground Circuit for an Open ]

No

• Repair the auto headlamps signal circuit for a short to ground.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 3 - Check Sensor Ground Circuit for an Open

• Measure the resistance of the sensor ground circuit between the sun sensor harness connector and the A/C heater control C1 harness connector.

Is the resistance less than 5 ohms?

Yes

• Go to Test Step 4 => [ Test Step 4 - Check the Sun Sensor ]

No

• Repair the sensor ground circuit for an open.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

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.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

No

• Replace the A/C heater control.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test