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.

### DTC Descriptor

DTC 10: Intake/Mode Door Error
DTC 11: Intake/Mode Door Error

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Intake Air Sensor Signal | 10, 11 | 10, 11 | 10, 11 | --
Ground | -- | 10, 11 | -- | --

### Circuit/System Description

The intake air sensor monitors the intake/mode door angle and its movement.

### Conditions for Running the DTC

• | The engine must be running.

• | The Heating Ventilation and Control module (HVAC) must be ON.

### Conditions for Setting the DTC

This DTC will set if the output of the mix door indicator indicates that the door opening angle is out of range or does not change value when the door should be moving. This would indicate a short circuit an open in the sensor or the associated wiring harness, a door motor that is not operating, or a malfunction of the HVAC module.

### Action Taken When the DTC Sets

• | The HVAC system stays in a default mode until the fault is cleared.

• | The diagnostic code remains on the display.

### Conditions for Clearing the DTC

The diagnostic code automatically clears after the fault has been rectified.

### Reference Information

#### Schematic Reference

HVAC Schematics

#### Connector End View Reference

HVAC Connector End Views

#### Description and Operation

Automatic HVAC Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Verification

Engine running, observe the HVAC control display. The HVAC control unit should be able to be adjusted to the desired mode.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the intake/mode door motor.
2. Test for less than 2 ohms of resistance between the ground circuit terminal 2 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, test for 5.5-6.5 volts between the 6-volt reference circuit terminal 3 and ground.

⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the FATC controller.

⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the HVAC controller.

4. Ignition ON, connect a test lamp between the supply voltage circuit terminal 1 and ground. The test lamp should turn ON.

⇒ | If the test lamp does not illuminate, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC controller.

5. If all circuits test normal, test or replace the intake/mode door motor.

### Component Testing

#### Static Test

Important: If continuity readings are inconsistent do not perform the static test.

1. Ignition OFF, disconnect the harness connector at the intake/mode door motor.
2. Test for 0-2 ohms of resistance between terminal 1 and terminal 2.

⇒ | If not within the specified range, replace the intake/mode door motor.

3. Test for infinite resistance between each terminal and the intake/mode door motor case.

⇒ | If not the specified value, replace the intake/mode door motor.

#### Dynamic Test

Important: Apply power and ground to the intake/mode door motor for no more than 5 seconds at a time or the component could be damaged.

Important: When performing the following tests, make sure that the device is not all ready in the position the test is attempting to produce.

1. Ignition OFF, disconnect the harness connector at the intake/mode door motor.
2. Install a 2A fused jumper wire between the control terminal 1 and 12 volts. Install a jumper wire between the control terminal 2 and ground. Momentarily install a jumper wire between the control terminal 3 and ground. The intake/mode door motor should move.

⇒ | If the function does not perform as specified, replace the intake/mode door motor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Heater and Air Conditioning Control Replacement for HVAC module replacement, setup and programming.

• | Mode Actuator Replacement