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 Descriptor

DTC P065E: Intake Manifold Tuning (IMT) Valve Performance.

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
5 Volt Reference | P0642 | -- | P065E | P0643 | --
IMT Valve Position Sensor Signal | P065E | P065E | P065E | P065E | P065E
Low Reference | -- | -- | P065E | -- | --

### Circuit/System Description

The intake manifold tuning (IMT) valve system uses variable air induction tuning in order to achieve maximum performance and efficiency over the entire operating range of the engine. The characteristic torque curve of a normally aspirated engine depends mainly on how the engines average pressure changes over the engine speed range. The average pressure is proportional to the volume of the air mass present in the cylinder when the inlet valve is closed. The design of the inlet system determines how large an air mass can be drawn into a cylinder at a given engine speed. An 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 2 smaller plenums. The 2 intake manifold plenum sizes result in different torque curves, which improves performance at low and high engine speeds. During low speed, high load conditions the IMT valve is closed, creating a longer runner path inside the plenum, which increases torque. During higher engine speeds and loads, the IMT valve opens creating a shorter runner path inside the plenum, which increases horsepower.

The IMT valve actuator solenoid has the following circuits:

• | Ignition 1 voltage

• | IMT Valve Actuator Solenoid Control

An IMT valve position sensor is mounted on the intake manifold. The IMT valve position sensor is a hall effect sensor and has the following circuits:

• | 5 volt reference

• | Low reference

• | Signal

The purpose of this diagnostic is to verify the open/closed position of the IMT valve by using the voltage signal supplied by the sensor to the ECM when it is commanded ON and OFF.

### Conditions for Running the DTC

• | DTC P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0642, P0643, P0652, P0653, P0652, P0653, P0661, P0662, P2227, P2228, or P2229 is not set.

• | The engine is running for greater than 3 seconds.

• | The engine speed is between 608-6,208 RPM.

• | The intake air temperature (IAT) is warmer than -10°C (14°F).

• | This DTC runs continuously within the enabling conditions.

### Conditions for Setting the DTC

• | The commanded ON or OFF position of the IMT valve is stable for greater than 0.5 second, and the ECM detects less than 1 volt on the IMT valve position sensor signal circuit, when the IMT valve is commanded OFF.

| OR

• | The commanded ON or OFF position of the IMT valve is stable for greater than 0.5 second, and the ECM detects greater than 4 volts on the IMT valve position sensor signal circuit, when the IMT valve is commanded ON.

### Action Taken When the DTC Sets

DTC P065E is a Type B DTC.

### Conditions for Clearing the MIL/DTCs

DTC P065E is a Type B DTC.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### 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

Control Module References for scan tool information.

### Circuit/System Verification

1. Verify that DTC P0642, P0643, P0652, or P0653 is not set.

⇒ | If any of the DTCs are set, refer to DTC P0642, P0643, P0652, or P0653.

2. Use the scan tool output controls to command the IMT Valve Actuator Solenoid parameter ON and OFF. Verify that the diaphragm arm moves at least once when there is sufficient vacuum in the storage tank.
3. Use the scan tool output controls to command the IMT Valve Actuator Solenoid parameter ON and OFF. An audible click should be heard and felt.
4. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

1. Verify that the IMT valve position sensor is properly attached and tightened at the intake manifold.
2. Ignition OFF for 90 seconds, disconnect the harness connector at the IMT valve position sensor.
3. Test for less than 5 ohms between the low reference circuit terminal 2 and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.

⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

5. Test for less than 0.10 volt between the signal circuit terminal 1 and ground.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

6. Ignition OFF for 90 seconds, test for 80k-120k ohms between the signal circuit terminal and ground.

⇒ | If not within the specified range, test the signal circuit for a short to ground or an open. If the circuit tests normal, replace the ECM.

7. Disconnect the harness connector X1 at the ECM.
8. Test for less than 5 ohms between the signal circuit terminal 1 and the ECM terminal 7 X1.

⇒ | If greater than the specified range, test the signal circuit for a high resistance.

9. If the circuits test normal, replace the intake manifold.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Intake Manifold Replacement

• | Control Module References for ECM replacement, setup, and programming