Blend Door Control Circuit Open (MTC)

B104F-BLEND DOOR CONTROL CIRCUIT OPEN (MTC)





For a complete wiring diagram refer to Diagrams/Electrical.

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) Front Common Door Driver circuit. All of the front door actuators share the (C34) Front Common Door Driver circuit. Inside the A/C Heater Control, each door actuator has its own unique driver, but all share a single common door driver circuit. Due to the shared circuitry similar DTCs can set at the same time for multiple actuators depending upon the location of the open circuit and the direction the actuator is moving when the open is present.

- When Monitored:

With the ignition on.

- Set Condition:

If Front Blend Door Actuator's electrical circuit is open. 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: DTC B104F must be active for the results of this test to be valid. Do not perform this test if DTC B104F is stored. Refer to HVAC System Test (MTC) for stored DTC test procedures. HVAC System Test (MTC)

Diagnostic Test

1.CHECK FOR ACTIVE CONTROL CIRCUIT/PERFORMANCE DTCs

Turn the ignition on.

With the scan tool, read active HVAC DTCs.

Does the scan tool display any active: XXXX CONTROL CIRCUIT/PERFORMANCE DTCs?

Yes

- Diagnose and repair the DTC(s).

No

- Go To 2

2.CHECK FRONT BLEND DOOR ACTUATOR CIRCUIT RESISTANCE





Turn the ignition off.

Disconnect the A/C Heater Control C1 harness connector.

Measure the resistance between the (C61) Front Blend Door Driver circuit and the (C34) Front Common Door Driver circuit in the A/C Heater Control C1 harness connector.

Is the resistance above 70 ohms?

Yes

- Go To 3

No

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

3.CHECK (C61) FRONT BLEND DOOR DRIVER CIRCUIT FOR AN OPEN





Disconnect the Front Blend Door Actuator harness connector.

Measure the resistance of the (C61) Front Blend Door Driver circuit between the A/C Heater Control C1 harness connector and the Front Blend Door Actuator harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 4

No

- Repair the (C61) Front Blend Door Driver circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

4.CHECK (C34) FRONT COMMON DOOR DRIVER CIRCUIT FOR AN OPEN





Measure the resistance of the (C34) Front Common Door Driver circuit between the A/C Heater Control C1 harness connector and the Front Blend Door Actuator harness connector.

Is the resistance below 5.0 ohms?

Yes

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

No

- Repair the (C34) Front Common Door Driver circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test