• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition Voltage | P0661* | P0660 | -- | -- |
IMT Control Circuit | P0661 | P0660 | P0662 | -- |
*Opens the fuse that supplies voltage to the IMT solenoid. |
An intake manifold tuning (IMT) valve is used to change the intake manifold plenum configuration. When the IMT valve is open, the intake manifold is configured to one large plenum. When the IMT valve is closed, the intake manifold is configured to two smaller plenums. The IMT valve improves engine performance at low and high engine speeds.
Ignition voltage is supplied directly to the IMT solenoid. The engine control module (ECM) controls the solenoid by grounding the control circuit with a solid state device called a driver. The driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage.
• | The engine is operating. |
• | The IMT solenoid has been commanded ON and OFF at least once during the ignition cycle. |
• | The DTCs run continuously once the above condition is met. |
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 4 seconds, or a cumulative of 30 seconds.
DTCs P0660, P0661, and P0662 are Type C DTCs.
DTCs P0660, P0661, and P0662 are Type C DTCs.
If the condition is intermittent, move the related harnesses and connectors with the engine operating. Monitor the scan tool Circuit Test Status parameters for the component. The Circuit Test Status parameter will change from OK or Not Run to Fault if there is a condition with the circuit or a connection.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Control Module References for scan tool information
⇒ | If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary. |
Note: The control circuit for the IMT solenoid is pulled-up to voltage within the ECM, 2.0-3.0 V on the control circuit is normal.
⇒ | 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. |
⇒ | If the voltage is not within the specified range, replace the ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for engine control module replacement, setup, and programming |