For 1990-2009 cars

### 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 Actuator Control A | 1 | 1 | 1 | --
Recirculation Actuator Control B | 1 | 1 | 1 | --
1. HVAC Recirculation Malfunction

### 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 recirculation door and recirculation actuator for the following:

• | A misaligned recirculation actuator.

• | Broken or binding linkages or recirculation door.

• | An obstruction that prevents the recirculation actuator from operating within the full range of motion.

• | Missing seals to the recirculation door.

### Reference Information

#### Schematic Reference

HVAC Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

• | Air Delivery Description and Operation

• | Air Temperature Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

1. Ignition ON, connect a test lamp between control circuit terminal 5 and control circuit terminal 6.
2. Command the recirculation actuator door in both directions with the HVAC controls. The test lamp should turn ON and OFF when commanded in both directions

⇒ | If the test lamp does not illuminate in both directions, test both control circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the HVAC control module.

3. If all circuits test normal, test or replace the recirculation actuator.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Heater and Air Conditioning Control Replacement

• | Recirculation Actuator Replacement