• | 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 | P2009* | P2008 | -- | P2076 |
IMT/IMRC Control Circuit | P2009, P2076 | P2008 | P2010 | P2076 |
IMT/IMRC Signal Circuit | P2077 | P2076, P2077, P2078 | P2076, P2077, P2078 | P2076 |
IMT/IMRC Ground | -- | P2076, P2077, P2078 | -- | P2076 |
*Opens the fuse that supplies voltage to the IMT/IMRC 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 IMT valve also contains a position sensor which is used to detect the actual position of the IMT valve in relation to its commanded position. The ECM supplies the IMT position sensor with a 5-volt signal circuit and the position sensor uses a common ground circuit. The position sensor enables the ECM to detect a physically broken or stuck IMT valve.
• | The ignition is ON or 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 IMT driver and the position sensor signal do not match for greater than 4 seconds, or for cumulative of 50 seconds.
DTCs P2076, P2077, and P2078 are Type B DTCs.
DTCs P2076, P2077, and P2078 are Type B DTCs.
If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool circuit test status parameters for the component. A 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 a DTC is set, refer to DTC P2008, P2009, or P2010. |
⇒ | If no audible click is heard, refer to Intake Manifold Runner Control System Diagnosis. |
⇒ | If greater than the specified range, test for an open/high resistance in the ground circuit. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the control module. |
⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the control module. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for engine control module replacement, setup, and programming |