B1012

B1012-DEFROST SWITCH REQUEST INPUT CIRCUIT/PERFORMANCE

For a complete wiring diagram Refer to the Wiring Information.

Theory of Operation

The switch input changes when the switch is pushed down. A stored DTC indicates that the defrost switch was stuck in a pushed position for more than 10 minutes, but has since returned to its normal state. An active DTC indicates that the defrost switch is stuck in a pushed position.

- When Monitored:
With the ignition on.

- Set Condition:
If the defrost switch is detected in a pushed position for more than 10 minutes.





1. VERIFY THE DTC IS STILL ACTIVE
1. Turn the ignition on.
2. With the scan tool, erase HVAC DTCs.
3. Turn the ignition off, wait 10 seconds, and then turn the ignition on. Wait 10 minutes before proceeding.
4. With the scan tool, read HVAC DTCs.

Does the scan tool display this DTC?

Yes

- Go To 2.

No

- The condition that caused this symptom is currently not present. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals. Repair as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

2. CHECK FOR NORMAL DEFROST SWITCH AND STATUS INDICATOR FUNCTION
1. Set the Blower control to any position except Off.
2. Set the Mode control to any position except Auto.
3. Press the Defrost switch on and off several times while observing the Defrost status indicator.

Does the Defrost status indicator turn on and off?

Yes

- Go To 4.

No

- Go To 3.

3. INSPECT FOR OBJECT OR SUBSTANCE CAUSING THE DEFROST SWITCH TO STAY OR STICK IN A PUSHED POSITION
1. Inspect the A/C Heater Control for anything that would cause the Defrost switch to stay or stick in a pushed position.

Is anything present that would cause the Defrost switch to stay or stick in a pushed position?

Yes

- Repair as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Go To 4.

4. INSPECT THE A/C HEATER CONTROL FOR DAMAGE
1. Inspect the A/C Heater Control for damage.

Is the A/C Heater Control damaged?

Yes

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

No

- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.