Manual Temperature Control
B1040 - Panel Mode Door 1 Control Circuit/Performance
For a complete wiring diagram, refer to.
Theory of Operation
The A/C heater control drives the mode door actuator via the mode door driver circuit and the common door driver 2 circuit. The mode door 1 actuator shares the common door driver 2 circuit with the passenger blend door actuator circuit, the driver blend door actuator circuit, and the recirculation door actuator circuit.
• When Monitored: With the ignition on.
• Set Condition: If the A/C heater control detects a short on the mode door driver circuit or the common door driver 2 circuit while attempting to drive this actuator.
• The DTC must be active for the results of this test to be valid. Do not perform this test if the DTC is stored. Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test For stored DTC test procedures.
Test Step 1 - Check Mode 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 mode door driver circuit in the A/C heater control C1 harness connector.
Is the voltage more than 0.2 volts?
Yes
• Repair the mode door 1 driver circuit for a short to voltage.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 2 => [ Test Step 2 - Check Driver Blend Door Actuator Circuit for a Short
to Voltage ]
Test Step 2 - Check Driver Blend Door Actuator Circuit for a Short to Voltage
• Measure the voltage between ground and the driver blend door actuator circuit in the A/C heater control C1 harness connector.
Is the voltage more than 0.2 volts?
Yes
• Repair the driver blend door actuator circuit for a short to voltage.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 8 => [ Test Step 8 - Check Recirculation Door Actuator Circuit for a Short
to Ground ]
Test Step 3 - Check Recirculation Door Actuator Circuit for a Short to Voltage
• Measure the voltage between ground and the recirculation door actuator circuit in the A/C heater control C1 harness connector.
Is the voltage more than 0.2 volts?
Yes
• Repair the recirculation door actuator circuit for a short to voltage.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 9 => [ Test Step 9 - Check Passenger Blend Door Actuator Circuit for a Short
to Ground ]
Test Step 4 - Check Passenger Blend Door Actuator Circuit for a Short to Voltage
• Measure the voltage between ground and the passenger blend door actuator circuit in the A/C heater control C1 harness connector.
Is the voltage more than 0.2 volts?
Yes
• Repair the passenger blend door actuator circuit for a short to voltage.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 5 => [ Test Step 5 - Check Common Door Driver 2 Circuit for a Short to Voltage ]
Test Step 5 - Check Common Door Driver 2 Circuit for a Short to Voltage
• Measure the voltage between ground and the common door driver 2 circuit in the A/C heater control C1 harness connector.
Is the voltage more than 0.2 volts?
Yes
• 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
No
• Go to Test Step 6 => [ Test Step 6 - Check Mode Door 1 Driver Circuit for a Short to Ground ]
Test Step 6 - Check Mode Door 1 Driver Circuit for a Short to Ground
• Turn the ignition OFF.
• Measure the resistance between ground and the mode door driver circuit in the A/C heater control C1 harness connector.
Is the resistance less than 10k ohms?
Yes
• 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
No
• Go to Test Step 7 => [ Test Step 7 - Check Driver Blend Door Actuator Circuit for a Short
to Ground ]
Test Step 7 - Check Driver Blend Door Actuator Circuit for a Short to Ground
• Measure the resistance between ground and the driver blend door actuator circuit in the A/C heater control C1 harness connector.
Is the resistance less than 10K ohms?
Yes
• Repair the driver blend door actuator circuit for a short to ground.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 8 => [ Test Step 8 - Check Recirculation Door Actuator Circuit for a Short
to Ground ]
Test Step 8 - Check Recirculation Door Actuator Circuit for a Short to Ground
• Measure the resistance between ground and the recirculation door actuator circuit in the A/C heater control C1 harness connector.
Is the resistance less than 10K ohms?
Yes
• Repair the recirculation door actuator circuit for a short to ground.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 9 => [ Test Step 9 - Check Passenger Blend Door Actuator Circuit for a Short
to Ground ]
Test Step 9 - Check Passenger Blend Door Actuator Circuit for a Short to Ground
• Measure the resistance between ground and the passenger blend door actuator circuit in the A/C heater control C1 harness connector.
Is the resistance less than 10K ohms?
Yes
• Repair the passenger blend door actuator circuit for a short to ground.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 10 => [ Test Step 10 - Check Common Door Driver 2 Circuit for a Short to
Ground ]
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 less than 10k ohms?
Yes
• 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
No
• Go to Test Step 11 => [ Test Step 11 - Check Mode Door Driver Circuit for a Short to Other
Door Driver Circuits ]
Test Step 11 - Check Mode Door Driver Circuit for a Short to Other Door Driver Circuits
• Measure the resistance between the mode door driver circuit and the common door driver 2 circuit, the recirculation door driver circuit, the passenger blend door driver circuit, and the driver blend door driver circuit in the A/C heater control C1 harness connector.
Is the resistance less than 100 ohms between the Mode Door 1 Driver circuit and any of the other door driver circuits?
Yes
• Repair the circuits with a resistance less than 100 ohms for a short to the mode door driver circuit.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 12 => [ Test Step 12 - Check Mode Door Actuator Circuit Resistance ]
Test Step 12 - 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 13 => [ Test Step 13 - Check Passenger 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 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 Driver Blend Door Actuator Circuit Resistance ]
No
• Replace the passenger blend door actuator.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
Test Step 14 - 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 15 => [ Test Step 15 - Check Recirculation Door Actuator Circuit Resistance ]
No
• Replace the driver blend door actuator.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
Test Step 15 - 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
• Replace the A/C heater control.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Replace the recirculation door actuator.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test