Floor/Defrost Mode Door Control Circuit High (ATC)

B1048-FLOOR/DEFROST MODE DOOR CONTROL CIRCUIT HIGH (ATC)

B1048-Floor/Defrost Mode Door Control Circuit High (ATC):

WHEN MONITORED
When the Actuator DTC Detection Test is executed.

SET CONDITION
If the (C801) Mode Door 2 Driver circuit is shorted to voltage.

POSSIBLE CAUSES
- (C801) mode door 2 driver circuit shorted to voltage
- A/C heater control

Theory Of Operation
The A/C Heater Control drives the Mode Door 2 (Floor to Defrost) Actuator via the (C801) Mode Door 2 Driver circuit and the (C808) Common Door Driver 3 circuit. The Mode Door 2 (Floor to Defrost) Actuator does not share the (C808) Common Door Driver 3 circuit with any other actuator. However, the Mode Door 2 (Floor to Defrost) Actuator, the Rear Mode Door Actuator, and the Rear Blend Door Actuator share a driver inside the A/C Heater Control. Due to the shared circuitry similar DTCs can set at the same time for multiple actuators depending upon the type of short, its location, and the direction the actuator is moving when the short is present.

Diagnostic Test

1. CHECK (C801) MODE DOOR 2 DRIVER CIRCUIT FOR A SHORT TO VOLTAGE




Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
Measure the voltage of the (C801) Mode Door 2 Driver circuit.

Q: Is the voltage above 0.2 volts?

YES: Repair the (C801) Mode Door 2 Driver circuit for a short to voltage. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 2

2. RUN THE ACTUATOR DTC DETECTION TEST
Turn the ignition off.
Reconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
With the scan tool in HVAC, select System Tests and then select Actuator DTC Detection. When the test is complete, select View DTCs.

Q: Does the scan tool only display: B1048-FLOOR/DEFROST MODE DOOR CONTROL CIRCUIT HIGH?

YES: Replace the A/C Heater Control in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO, Other DTC(s) Displayed
Diagnose and repair the other DTC(s). If multiple DTCs are present, beginning with the common circuits, diagnose and repair all short high DTCs and then all short low DTCs.
NO, And No Other DTCs Displayed
Using the wiring diagram as a guide, inspect the wiring and connectors for conditions causing an intermittent short. Repair as necessary. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test