GM Service Manual Online
For 1990-2009 cars only

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

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ignition 1 Voltage

1

P0660

P0660

--

IMT Valve Control Circuit

P0660

P0660

P0660

--

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 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 more than 10 volts.
    •  DTC P0660 runs continuously once the above condition is met.

Conditions for Setting the DTC

The ECM detects an open or short to ground or voltage on the control circuit of the IMT valve solenoid.

Action Taken When the DTC Sets

DTC P0660 is a Type C DTC.

Conditions for Clearing the DTC

DTC P0660 is a Type C DTC.

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, 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 Data List.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector of the IMT valve solenoid.
  2. Important: The test lamp is used to load the circuit and may not illuminate.

  3. Connect a test lamp between the ignition 1 voltage circuit of the IMT valve solenoid and ground.
  4. Ignition ON, load test for battery voltage between the ignition 1 voltage circuit of the IMT valve solenoid and ground.
  5. 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.
  6. With the ignition OFF, connect a test lamp between the control circuit and the ignition 1 voltage circuit of the IMT valve solenoid.
  7. 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.
  8. 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.
  9. If all circuits/connections test normal, replace the IMT valve solenoid.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming