B160F

B160F-AMBIENT LIGHT SENSOR INPUT CIRCUIT PERFORMANCE (MTC)

For a complete wiring diagram REFER to DIAGRAMS/ELECTRICAL .


- When Monitored:
With the ignition on.

- Set Condition:
If the Ambient Light Sensor input is out of range.







NOTE: This DTC must be active for the results of this test to be valid. Do not perform this test if this DTC is stored. Refer to HVAC System Test (ATC) for stored DTC test procedures. Heating-A/C System Diagnostics


Diagnostic Test


1. CHECK (L24) 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 (L24) Auto Headlamps Signal circuit between the Sun Sensor harness connector and the A/C Heater Control C1 harness connector.
Is the resistance below 5 ohms?

Yes


- Go To 2


No


- Repair the (L24) Auto Headlamps Signal circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.


2. CHECK (L24) AUTO HEADLAMPS SIGNAL CIRCUIT FOR A SHORT TO GROUND
Measure the resistance between ground and the (L24) Auto Headlamps Signal circuit in the A/C Heater Control C1 harness connector.
Is the resistance above 10k ohms?

Yes


- Go To 3


No


- Repair the (L24) Auto Headlamps Signal circuit for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.


3. CHECK (C121) SENSOR GROUND CIRCUIT FOR AN OPEN
Measure the resistance of the (C121) Sensor Ground circuit between the Sun Sensor harness connector and the A/C Heater Control C1 harness connector.
Is the resistance below 5 ohms?

Yes


- Go To 4


No


- Repair the (C121) Sensor Ground circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.


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 (L24) Auto Headlamps Signal circuit and the (C121) 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 BODY VERIFICATION TEST - VER 1.Body Verification Test.


No


- Replace the A/C Heater Control.
- Perform BODY VERIFICATION TEST - VER 1.Body Verification Test.