Climate Control Motor(S) Common 1 Control Circuit Low (ATC)
B105F-CLIMATE CONTROL MOTOR(S) COMMON 1 CONTROL CIRCUIT LOW (ATC)B105F-Climate Control Motor(s) Common 1 Control Circuit Low (ATC):
WHEN MONITORED
When the Actuator DTC Detection Test is executed.
SET CONDITION
If the (C34) Common Door Driver 1 circuit is shorted to ground.
POSSIBLE CAUSES
- (C34) Common door driver 1 circuit shorted to ground
- (C34) Common door driver 1 circuit shorted to other door driver circuit(s)
- Front blend door actuator
- Recirculation door actuator
- A/C heater control
Theory Of Operation
The A/C Heater Control drives the Front Blend Door Actuator via the (C61) Front Blend Door Driver circuit and the (C34) Common Door Driver 1 circuit. The A/C Heater Control drives the Recirculation Door Actuator via the (C32) Recirculation Door Driver circuit and the (C34) Common Door Driver 1 circuit. The Front Blend Door Actuator and the Recirculation Door Actuator share the (C34) Common Door Driver 1 circuit and they 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 (C34) COMMON DOOR DRIVER 1 CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance of the (C34) Common Door Driver 1 circuit between ground and the A/C Heater Control C1 harness connector.
Q: Is the resistance below 10k ohms?
YES: Repair the (C34) Common Door Driver 1 circuit for a short to ground. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 2
2. CHECK (C34) COMMON DOOR DRIVER 1 CIRCUIT FOR A SHORT TO OTHER DOOR DRIVER CIRCUITS
Measure the resistance between the (C34) Common Door Driver 1 circuit and the (C54) Rear Blend Door Driver circuit, the (C808) Common Door Driver 3 circuit, the (C154) Rear Common Door Driver circuit, the (C53) Rear Mode Door Driver circuit, the (C801) Mode Door 2 Driver circuit, the (C807) Common Door Driver 2 circuit, and the (C29) Mode Door 1 Driver circuit in the A/C Heater Control C1 harness connector.
Q: Is the resistance below 10k ohms between the (C34) Common Door Driver 1 circuit and any of the other door driver circuits?
YES: Repair the circuits with a resistance below 10k ohms for a short to the (C34) Common Door Driver 1 circuit. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 3
3. CHECK FRONT BLEND DOOR ACTUATOR CIRCUIT RESISTANCE
Measure the resistance between the (C61) Front Blend Door Driver circuit and the (C34) Common Door Driver 1 circuit in the A/C Heater Control C1 harness connector.
Q: Is the resistance below 30 ohms?
YES: Go To 4
NO: Go To 5
4. CHECK (C61) FRONT BLEND DOOR DRIVER CIRCUIT FORA SHORT TO (C34) COMMON DOOR DRIVER 1 CIRCUIT
Disconnect the Front Blend Door Actuator harness connector.
Measure the resistance between the (C61) Front Blend Door Driver circuit and the (C34) Common Door Driver 1 circuit in the A/C Heater Control C1 harness connector.
Q: Is the resistance below 10k ohms?
YES: Repair the (C61) Front Blend Door Driver Circuit for a short to the (C34) Common Door Driver 1 circuit. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace the Front Blend Door Actuator in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
5. CHECK RECIRCULATION DOOR ACTUATOR CIRCUIT RESISTANCE
Measure the resistance between the (C32) Recirculation Door Driver circuit and the (C34) Common Door Driver 1 circuit in the A/C Heater Control C1 harness connector.
Q: Is the resistance below 30 ohms?
YES: Go To 6
NO: Go To 7
6. CHECK (C32) RECIRCULATION DOOR DRIVER CIRCUIT FOR A SHORT TO (C34) COMMON DOOR DRIVER 1 CIRCUIT
Disconnect the Recirculation Door Actuator harness connector.
Measure the resistance between the (C32) Recirculation Door Driver circuit and the (C34) Common Door Driver 1 circuit in the A/C Heater Control C1 harness connector.
Q: Is the resistance below 10k ohms?
YES: Repair the (C32) Recirculation Door Driver circuit for a short to the (C34) Common Door Driver 1 circuit. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace the Recirculation Door Actuator in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
7. RUN THE ACTUATOR DTC DETECTION TEST
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: B105F-CLIMATE CONTROL MOTOR(S) COMMON 1 CONTROL CIRCUIT LOW?
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