Manual Temperature Control

B1055 - Rear Blend Door Control Circuit Open

For a complete wiring diagram, refer to.

Theory of Operation

The A/C heater control drives the rear mode door actuator via the rear mode door driver circuit and the rear common door driver circuit. The A/C heater control drives the rear blend door actuator via the rear blend door driver circuit and the common door driver circuit.

• When Monitored: With the ignition on.

• Set Condition: If the rear blend door actuator electrical circuit is open.






• DTC B1055 must be active for the results of this test to be valid. Do not perform this test if DTC B1055 is stored. Refer to HVAC system test (ATC) for stored DTC test procedures.

Test Step 1 - Check for an Active Control Circuit/Performance DTCs

• Turn the ignition ON.

• With the scan tool, read active HVAC DTCs.

Does the Scan Tool Display any Active Control Circuit/Performance DTCs?

Yes

• Diagnose and repair the DTCs. If present, diagnose and repair all rear blend and rear mode door control circuit/performance DTCs first, then all other control circuit/performance DTCs next. Refer to the table of contents in this section for a complete list of all HVAC related symptoms.

No

• Go to Test Step 2 => [ Test Step 2 - Check Rear Blend Door Driver Circuit for an Open ]

Test Step 2 - Check Rear Blend Door Driver Circuit for an Open

• Turn the ignition OFF.

• Disconnect the A/C heater control C1 harness connector.

• Disconnect the rear blend door actuator harness connector.

• Measure the resistance of the rear blend door driver circuit between the A/C heater control C1 harness connector and the rear blend door actuator harness connector.

Is the resistance less than 5.0 ohms?

Yes

• Go to Test Step 3 => [ Test Step 3 - Check Common Door Driver Circuit for an Open ]

No

• Repair the rear blend door driver circuit for an open.

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

Test Step 3 - Check Common Door Driver Circuit for an Open

• Measure the resistance of the common door driver circuit between the A/C heater control C1 harness connector and the rear blend door actuator harness connector.

Is the resistance less than 5.0 ohms?

Yes

• Go to Test Step 4 => [ Test Step 4 - Check Rear Blend Door Actuator Circuit Resistance ]

No

• Repair the rear common door driver circuit for an open.

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

Test Step 4 - Check Rear Blend Door Actuator Circuit Resistance

• Reconnect the rear blend door actuator harness connector.

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

Is the resistance between 30 and 40 ohms?

Yes

• Replace the rear blend door actuator.

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

No

• Replace the A/C heater control.

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