Operation CHARM: Car repair manuals for everyone.

Manual Temperature Control






B10A2 - Left Blend Door Control Circuit/Performance

For a complete wiring diagram, refer to.

Theory of Operation

The A/C heater control monitors the door driver circuits during actuator operation for shorts to ground, shorts to battery, and shorts to other door driver circuits. If detected, the A/C heater control reports these types of faults as control circuit/performance DTCs.

When Monitored: When actuator movement is requested.

Set Condition: If the A/C heater control detects a short to ground or to voltage on the recirculation door driver, the passenger blend door driver, the driver blend door driver, the mode door driver, or the common door driver 2 circuits while attempting to drive the recirculation door driver.






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 => Non-DTC Based Diagnostics for stored DTC test procedures.

Test Step 1 - Check Recirculation Door 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 recirculation door driver circuit in the A/C heater control C1 harness connector.

Is the voltage less than 0.2 volts?

Yes

Go to Test Step 2 => [ Test Step 2 - Check Passenger Blend Door Driver Circuit for a Short
to Voltage ]

No

Repair the recirculation door driver circuit for a short to voltage.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 2 - Check Passenger Blend Door Driver Circuit for a Short to Voltage






Measure the voltage of the passenger blend door driver circuit in the A/C heater control C1 harness connector.

Is the voltage less than 0.2 volts?

Yes

Go to Test Step 3 => [ Test Step 3 - Check Mode Door Driver Circuit for a Short to Voltage ]

No

Repair the passenger blend door driver circuit for a short to voltage.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 3 - Check Mode Door Driver Circuit for a Short to Voltage

Measure the voltage of the mode door driver circuit in the A/C heater control C1 harness connector.

Is the voltage less than 0.2 volts?

Yes

Go to Test Step 4 => [ Test Step 4 - Check Driver Blend Door Driver Circuit for a Short
to Voltage ].

No

Repair the mode door driver circuit for a short to voltage.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 4 - Check Driver Blend Door Driver Circuit for a Short to Voltage






Measure the voltage of the driver blend door driver circuit in the A/C heater control C1 harness connector.

Is the voltage less than 0.2 volts?

Yes

Go to Test Step 5 => [ Test Step 5 - Check Common Door Driver 2 Circuit for a Short to Voltage ]

No

Repair the driver blend door driver circuit for a short to voltage.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 5 - Check Common Door Driver 2 Circuit for a Short to Voltage

Measure the voltage of the common door driver 2 circuit in the A/C heater control C1 harness connector.

Is the voltage less than 0.2 volts?

Yes

Go to Test Step 6 => [ Test Step 6 - Check Recirculation Door Driver Circuit for a Short
to Ground ]

No

Repair the common door driver 2 circuit for a short to voltage.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 6 - Check Recirculation Door Driver Circuit for a Short to Ground

Turn the ignition OFF.

Measure the resistance between ground and the recirculation door driver circuit in the A/C heater control C1 harness connector.

Is the resistance more than 10k ohms?

Yes

Go to Test Step 7 => [ Test Step 7 - Check Passenger Blend Door Driver Circuit for a Short
to Ground ]

No

Repair the recirculation door driver circuit for a short to ground.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 7 - Check Passenger Blend Door Driver Circuit for a Short to Ground

Measure the resistance between ground and the passenger blend door driver circuit in the A/C heater control C1 harness connector.

Is the resistance more than 10k ohms?

Yes

Go to Test Step 8 => [ Test Step 8 - Check Driver Blend Door Driver Circuit for a Short
to Ground ]

No

Repair the passenger blend door driver circuit for a short to ground.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 8 - Check Driver Blend Door Driver Circuit for a Short to Ground






Measure the resistance between ground and the driver blend door driver circuit in the A/C heater control C1 harness connector.

Is the resistance more than 10k ohms?

Yes

Go to Test Step 9 => [ Test Step 9 - Check Mode Door Driver Circuit for a Short to Ground ]

No

Repair the driver blend door driver circuit for a short to ground.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 9 - Check Mode Door Driver Circuit for a Short to Ground

Measure the resistance between ground and the mode door driver circuit in the A/C heater control C1 harness connector.

Is the resistance more than 10k ohms?

Yes

Go to Test Step 10 => [ Test Step 10 - Check Common Door Driver 2 Circuit for a Short to
Ground ]

No

Repair the Mode door driver circuit for a short to ground.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 10 - Check Common Door Driver 2 Circuit for a Short to Ground

Measure the resistance between ground and the common door driver 2 circuit in the A/C heater control C1 harness connector.

Is the resistance more than 10k ohms?

Yes

Go to Test Step 11 => [ Test Step 11 - Check Recirculation Door Driver Circuit for a Short
to Other Door Driver Circuits ]

No

Repair the common door driver 2 circuit for a short to ground.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 11 - Check Recirculation Door Driver Circuit for a Short to Other Door Driver Circuits

Measure the resistance between the recirculation door driver circuit and the passenger blend door driver circuit, driver blend door driver circuit, the common door driver 2 circuit, and the mode door driver circuit in the A/C heater control C1 harness connector.

Is the resistance more than 100 ohms between the recirculation door driver circuit and all door driver circuits?

Yes

Go to Test Step 12 => [ Test Step 12 - Check Recirculation Door Actuator Circuit Resistance ]

No

Repair the circuits with a resistance less than 100 ohms for a short to the recirculation door driver circuit.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 12 - Check Recirculation Door Actuator Circuit Resistance






Measure the resistance between the recirculation door driver circuit and the common door driver 2 circuit in the A/C heater control C1 harness connector.

Is the resistance between 30 and 40 ohms?

Yes

Go to Test Step 13 => [ Test Step 13 - Check Passenger Blend Door Actuator Circuit Resistance ]

No

Replace the recirculation door actuator.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 13 - Check Passenger Blend Door Actuator Circuit Resistance






Measure the resistance between the passenger blend door driver circuit and the common door driver 2 circuit in the A/C heater control C1 harness connector.

Is the resistance between 30 and 40 ohms?

Yes

Go to Test Step 14 => [ Test Step 14 - Check Mode Door Actuator Circuit Resistance ]

No

Replace the passenger door actuator.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 14 - Check Mode Door Actuator Circuit Resistance

Measure the resistance between the mode door driver circuit and the common door driver 2 circuit in the A/C heater control C1 harness connector.

Is the resistance between 30 and 40 ohms?

Yes

Go to Test Step 15 => [ Test Step 15 - Check Driver Blend Door Actuator Circuit Resistance ]

No

Replace the mode door actuator.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 15 - Check Driver Blend Door Actuator Circuit Resistance






Measure the resistance between the driver blend door driver circuit and the common door driver 2 circuit in the A/C heater control C1 harness connector.

Is the resistance between 30 and 40 ohms?

Yes

Go to Test Step 16 => [ Test Step 16 - Run the Actuator Calibration Test ]

No

Replace the mode door actuator.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 16 - 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 B1058 - Recirculation Door Control Circuit/Performance?

Yes

Replace the A/C heater control.

Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

No, Other DTCs Displayed

Diagnose and repair the other DTCs. Refer to the table of contents in this section for a complete list of all HVAC related symptoms.

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 the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test