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 Descriptors

DTC P0661: Intake Manifold Tuning (IMT) Valve Solenoid Control Circuit Low Voltage
DTC P0662: Intake Manifold Tuning (IMT) Valve Solenoid Control Circuit High Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition 1 Voltage | * | P0661 | -- | --
IMT Valve Control Circuit | P0661 | P0661 | P0662 | --
*The Engine Cranks but Does Not Run and opens the fuse that supplies voltage to the IMT valve solenoid.

### Circuit/System Description

An ignition 1 voltage is supplied directly to the intake manifold tuning (IMT) valve solenoid. The engine control module (ECM) controls the IMT valve solenoid by grounding the control circuit via an internal driver switch. The primary function of the driver is to supply ground for the IMT valve solenoid. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the voltage on the control circuit.

### Conditions for Running the DTC

• | The ignition is ON.

• | DTCs P0661 and P0662 run continuously when the above condition is met.

### Conditions for Setting the DTC

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for more than 2 seconds.

### Action Taken When the DTC Sets

DTCs P0661 and P0662 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0661 and P0662 are Type B DTCs.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### Description and Operation

Air Intake System Description

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Ignition On, command the IMT valve solenoid ON and OFF with a scan tool. You should hear and feel an audible click.
2. If the vehicle passes the Circuit/System Verification Test, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records data list.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the IMT valve solenoid.
2. Ignition ON, load test for battery voltage between the ignition 1 voltage circuit of the IMT valve solenoid and ground.

⇒ | If less than B+, repair the ignition 1 voltage circuit of the IMT valve solenoid for a short to ground or an open/high resistance. Replace the fuse, if necessary.

3. With the ignition OFF, connect a test lamp between the control circuit and the ignition 1 voltage circuit of the IMT valve solenoid.
4. With the ignition ON, use a scan tool to command the IMT valve solenoid ON and OFF. The test lamp should turn ON and OFF with the command.

⇒ | If the test lamp remains ON all the time, test for a short to ground on the control circuit. If circuit/connections test normal, replace the ECM.

⇒ | If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the control circuit. If circuit/connections test normal, replace the ECM.

5. If all circuits/connections test normal, replace the IMT valve solenoid.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Intake Manifold Tuning Valve Actuator Solenoid Replacement

• | Control Module References for engine control module replacement, setup, and programming