Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Recirculation Door Control A | 1 | 1 | 1 | -- |
Recirculation Door Control B | 1 | 1 | 1 | -- |
1. Recirculation Actuator Inoperative | ||||
Circuit/System Description
The recirculation actuator is a 2-wire bi-directional electric motor. There are 2 control circuits that enable the actuator to operate. The control circuits use either a 0 or 12-volt value to coordinate the actuator movement. When the actuator is at rest, both control circuits have a value of 0 volts. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 volts. The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction.
Diagnostic Aids
Inspect the air temperature door and the mode actuator for the following conditions:
| • | A misaligned recirculation actuator |
| • | Broken or binding linkages or recirculation door |
| • | An obstruction that prevents the recirculation door from operating within its full range of motion |
| • | Missing seals to the recirculation door |
| • | Misaligned seals to the recirculation door |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the operation of the drive shaft of the recirculation actuator while using the recirculation control switch. The drive shaft of the recirculation actuator should rotate.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the recirculation actuator.
- Ignition ON, connect a test lamp between the control circuit terminal A and control circuit terminal B. Place the actuator switch in each direction. The test lamp should briefly illuminate when commanding the actuator from one direction to the other.
- If all circuits test normal, test or replace the recirculation actuator.
| ⇒ | If the test lamp is always OFF, test both control circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the HVAC control module. |
| ⇒ | If the test lamp is always ON, test both control circuits for a short to voltage. If the circuits test normal, replace the HVAC control module. |
Component Testing
- Install a 10-amp fused jumper wire between the control terminal A and 12 volts. Momentarily install a jumper wire between the control terminal B and ground. The recirculation actuator shaft should rotate.
- Reverse the jumper wires; the recirculation actuator shaft should rotate.
| ⇒ | If the function does not perform as specified, replace the recirculation actuator. |
| ⇒ | If the function does not perform as specified, replace the recirculation actuator. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for HVAC replacement, setup, and programming |
