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 provide an overview of each diagnostic category.

### DTC Descriptor

DTC P0660: Intake Manifold Tuning (IMT) Valve Solenoid Control Circuit

### Circuit/System Description

An ignition 1 voltage is supplied directly to the intake manifold tuning (IMT) valve solenoid or variable geometry induction system (VGIS). 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 engine is operating.

• | The ignition 1 voltage is between 7-16 volts.

• | DTC P0660 runs continuously once 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 greater than 10 seconds.

### Action Taken When the DTC Sets

DTC P0660 is a Type B DTC.

### Conditions for Clearing the DTC

DTC P0660 is a Type B DTC.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Controls Connector End Views

• | Engine Control Module 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. Engine idling, command the IMT valve ON with a scan tool. The IMT valve vacuum actuator should move to the closed position.
2. If the vehicle passes the Circuit/System Verification test, then 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 List.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the IMT valve solenoid.
2. Ignition ON, verify a test lamp illuminates between the ignition 1 voltage circuit and ground.

⇒ | If the test lamp does not illuminate, repair the ignition 1 voltage circuit 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.
4. Engine idling, command the IMT valve solenoid ON and OFF with a scan tool. The test lamp should turn ON when the solenoid is commanded OFF, and OFF when the solenoid is commanded ON.

⇒ | 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 ECM replacement, setup, and programming