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 Descriptors

DTC P02E1 11: Intake Air Flow Valve Control Performance Above Maximum Threshold
DTC P02E1 12: Intake Air Flow Valve Control Performance Below Minimum Threshold

### Circuit/System Description

A throttle plate actuator is used to achieve high exhaust gas recirculation rates. It increases the pressure difference between exhaust and intake so that the appropriate exhaust quantity can be mixed with the intake air. The ECM transmits the desired angle as a PWM signal to the throttle plate actuator. The throttle plate actuator operates the DC motor to control the throttle plate based on the PWM signal from the ECM. The throttle plate position is monitored by an internal position sensor.

### Conditions for Running the DTC

• | The ignition is ON, or the engine is running.

• | The DTCs run continuously when the above conditions are met.

### Conditions for Setting the DTC

The ECM detects the airflow deviation is above or below a calibrated amount during the regeneration process.

### Action Taken When the DTC Sets

DTC P02E1 is Type A DTC.

### Conditions for Clearing the DTC

DTC P02E1 is Type A 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. Ignition ON, command the throttle position from 0-95 percent with a scan tool. The throttle blade should respond to the scan tool commands.
2. Observe the DTC information with a scan tool. DTC P02E1 should not set.
3. 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. Ignition OFF, inspect for the following:

• | Intake system/charge air hoses for leaks/restrictions

• | Exhaust system/turbo charger for leaks/restrictions

• | Air filter for restrictions

⇒ | If a condition is found, repair as necessary.

2. Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the Q38 throttle body assembly.
3. Test for less than 5 Ω between the ground circuit terminal 1 and ground.

⇒ | If greater than the specified range, repair the ground circuit for an open/high resistance.

4. Install the MAIN fuse. Ignition ON, test for B+ between the battery voltage circuit terminal 2 and ground.

⇒ | If less than the specified range, repair the B+ circuit for an open/high resistance.

5. Connect a test lamp between the Q38 throttle blade control circuit terminal 3 and B+.
6. Command the throttle position from 0-95 percent with a scan tool. The test lamp should respond to the scan tool commands.

⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

7. If all circuits test normal, replace the throttle body assembly.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Throttle Body Assembly Replacement

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