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Floor/Defrost Mode Door Control Circuit/Performance (ATC)






B1046-FLOOR/DEFROST MODE DOOR CONTROL CIRCUIT/PERFORMANCE (ATC)





For a complete wiring diagram refer to Diagrams/Electrical.

Theory of Operation

The A/C Heater Control drives the Rear Mode Door Actuator via the (C53) Rear Mode Door Driver circuit and the (C154) Rear Common Door Driver circuit. The A/C Heater Control drives the Rear Blend Door Actuator via the (C54) Rear Blend Door Driver circuit and the (C154) Rear Common Door Driver circuit. In addition, the Rear Mode Door Actuator, the Rear Blend Door Actuator, and the Mode Door 2 (Floor to Defrost) 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.

- When Monitored:

With the ignition on.

- Set Condition:

If the A/C Heater Control detects a short on the (C53) Rear Mode Door Driver circuit, the (C54) Rear Blend Door Driver circuit, the (C801) Mode Door 2 Driver circuit, the (C154) Rear Common Door Driver circuit, or the (C808) Common Door Driver 3 circuit while attempting to drive the Rear Mode Door Actuator, the Rear Blend Door Actuator, or the Mode Door 2 (Floor to Panel) Actuator. This DTC has a maturing time of 5 seconds and a de-maturing time of 10 seconds. If the DTC's status changes from active to stored, it will stay in memory for 100 ignition cycles.





NOTE: The DTC must be active for the results of this test to be valid. Do not perform this test if the DTC is stored. Refer to HVAC System Test (ATC) for stored DTC test procedures. HVAC System Test (ATC)

Diagnostic Test

1.CHECK (C53) REAR MODE DOOR DRIVER CIRCUIT, (C54) REAR BLEND DOOR DRIVER CIRCUIT, (C808) COMMON DOOR DRIVER 3 CIRCUIT, (C154) REAR COMMON DOOR DRIVER CIRCUIT, & (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 (C53) Rear Mode Door Driver circuit.

Measure the voltage of the (C54) Rear Blend Door Driver circuit.

Measure the voltage of the (C808) Common Door Driver 3 circuit.

Measure the voltage of the (C154) Rear Common Door Driver circuit.

Measure the voltage of the (C801) Mode Door 2 Driver circuit.

Is the voltage above 0.2 volts on any of the circuits?

Yes

- Repair the circuit(s) with voltage above 0.2 volts for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 2

2.CHECK (C53) REAR MODE DOOR DRIVER CIRCUIT, (C54) REAR BLEND DOOR DRIVER CIRCUIT, (C808) COMMON DOOR DRIVER 3 CIRCUIT, (C154) REAR COMMON DOOR DRIVER CIRCUIT, & (C801) MODE DOOR 2 DRIVER
CIRCUIT FOR A SHORT TO GROUND






Turn the ignition off.

Measure the resistance of the (C53) Rear Mode Door Driver circuit between ground and the A/C Heater Control C1 harness connector.

Measure the resistance of the (C54) Rear Blend Door Driver circuit between ground and the A/C Heater Control C1 harness connector.

Measure the resistance of the (C808) Common Door Driver 3 Circuit between ground and the A/C Heater Control C1 harness connector.

Measure the resistance of the (C154) Rear Common Door Driver circuit between ground and the A/C Heater Control C1 harness connector.

Measure the resistance of the (C801) Mode Door 2 Driver circuit between ground and the A/C Heater Control C1 harness connector.

Is the resistance below 10k ohms on any of the circuits?

Yes

- Repair the circuit(s) with a resistance below 10k ohms for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 3

3.CHECK (C53) REAR MODE DOOR DRIVER CIRCUIT FOR A SHORT TO OTHER DOOR DRIVER CIRCUIT(S)





Measure the resistance between the (C53) Rear Mode Door Driver circuit and the (C54) Rear Blend Door Driver circuit, the (C808) Common Door Driver 3 circuit, the (C32) Recirculation Door Driver circuit, the (C34) Common Door Driver 1 circuit, the (C801) Mode Door 2 Driver circuit, the (C807) Common Door Driver 2 circuit, the (C29) Mode Door 1 Driver circuit, and the (C61) Front Blend Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 100 ohms between any of the circuits?

Yes

- Repair the circuit(s) with a resistance below 100 ohms for a short together.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 4

4.CHECK (C54) REAR BLEND DOOR DRIVER CIRCUIT FOR A SHORT TO OTHER DOOR DRIVER CIRCUIT(S)





Measure the resistance between the (C54) Rear Blend Door Driver circuit and the (C808) Common Door Driver 3 circuit, the (C32) Recirculation Door Driver circuit, the (C34) Common Door Driver 1 circuit, the (C801) Mode Door 2 Driver circuit, the (C807) Common Door Driver 2 circuit, the (C29) Mode Door 1 Driver circuit, and the (C61) Front Blend Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 100 ohms between any of the circuits?

Yes

- Repair the circuit(s) with a resistance below 100 ohms for a short together.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 5

5.CHECK (C154) REAR COMMON DOOR DRIVER CIRCUIT FOR A SHORT TO OTHER DOOR DRIVER CIRCUIT(S)





Measure the resistance between the (C154) Rear Common Door Driver circuit and the (C808) Common Door Driver 3 circuit, the (C32) Recirculation Door Driver circuit, the (C34) Common Door Driver 1 circuit, the (C801) Mode Door 2 Driver circuit, the (C807) Common Door Driver 2 circuit, the (C29) Mode Door 1 Driver circuit, and the (C61) Front Blend Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 100 ohms between any of the circuits?

Yes

- Repair the circuit(s) with a resistance below 100 ohms for a short together.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 6

6.CHECK (C808) COMMON DOOR DRIVER 3 CIRCUIT FOR A SHORT TO OTHER DOOR DRIVER CIRCUIT(S)





Measure the resistance between the (C808) Common Door Driver 3 circuit and the (C32) Recirculation Door Driver circuit, the (C34) Common Door Driver 1 circuit, the (C807) Common Door Driver 2 circuit, the (C29) Mode Door 1 Driver circuit, and the (C61) Front Blend Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 100 ohms between any of the circuits?

Yes

- Repair the circuit(s) with a resistance below 100 ohms for a short together.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 7

7.CHECK (C801) MODE DOOR 2 DRIVER CIRCUIT FOR A SHORT TO OTHER DOOR DRIVER CIRCUIT(S)





Measure the resistance between the (C801) Mode Door 2 Driver circuit and the (C32) Recirculation Door Driver circuit, the (C34) Common Door Driver 1 circuit, the (C807) Common Door Driver 2 circuit, the (C29) Mode Door 1 Driver circuit, and the (C61) Front Blend Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 100 ohms between any of the circuits?

Yes

- Repair the circuit(s) with a resistance below 100 ohms for a short together.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 8

8.CHECK REAR MODE DOOR ACTUATOR CIRCUIT RESISTANCE





Measure the resistance between the (C53) Rear Mode Door Driver circuit and the (C154) Rear Common Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 30 ohms?

Yes

- Go To 9

No

- Go To 10

9.CHECK (C53) REAR MODE DOOR DRIVER CIRCUIT FOR A SHORT TO (C154) REAR COMMON DOOR DRIVER CIRCUIT





Disconnect the Rear Mode Door Actuator harness connector.

Measure the resistance between the (C53) Rear Mode Door Driver circuit and the (C154) Rear Common Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the (C53) Rear Mode Door Driver circuit for a short to the (C154) Rear Common Door Driver circuit.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Replace the Rear Mode Door Actuator.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

10.CHECK REAR BLEND DOOR ACTUATOR CIRCUIT RESISTANCE





Measure the resistance between the (C54) Rear Blend Door Driver circuit and the (C154) Rear Common Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 30 ohms?

Yes

- Go To 11

No

- Go To 12

11.CHECK (C54) REAR BLEND DOOR DRIVER CIRCUIT FOR A SHORT TO (C154) REAR COMMON DOOR DRIVER CIRCUIT





Disconnect the Rear Blend Door Actuator harness connector.

Measure the resistance between the (C54) Rear Blend Door Driver circuit and the (C154) Rear Common Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the (C54) Rear Blend Door Driver circuit for a short to the (C154) Rear Common Door Driver circuit.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Replace the Rear Blend Door Actuator.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

12.CHECK MODE DOOR 2 (FLOOR TO DEFROST) ACTUATOR CIRCUIT RESISTANCE





Measure the resistance between the (C801) Mode Door 2 Driver circuit and the (C808) Common Door Driver 3 circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 30 ohms?

Yes

- Go To 13

No

- Go To 14

13.CHECK (C801) MODE DOOR 2 DRIVER CIRCUIT FOR A SHORT TO (C808) COMMON DOOR DRIVER 3 CIRCUIT





Disconnect the Mode Door 2 (Floor to Defrost) Actuator harness connector.

Measure the resistance between the (C801) Mode Door 2 Driver circuit and the (C808) Common Door Driver 3 circuit in the A/C Heater Control C1 harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the (C801) Mode Door 2 Driver circuit for a short to the (C808) Common Door Driver 3 circuit.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Replace the Mode Door 2 (Floor to Defrost) Actuator.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

14.RUN THE ACTUATOR CALIBRATION TEST

Reconnect the A/C Heater Control C1 harness connector.

Turn the ignition on.

With the scan tool, erase HVAC DTCs.

Turn the ignition off, wait 10 seconds, and then turn the ignition on.

With the scan tool, select System Tests and then select Actuator Calibration Test. When the test is complete, select View DTCs.

Does the scan tool only display: B1046-FLOOR/DEFROST MODE DOOR CONTROL CIRCUIT/PERFORMANCE?

Yes

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

No, Other DTC(s) Displayed

- Diagnose and repair the other DTC(s).

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