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 provides an overview of each diagnostic category.

DTC Descriptors

DTC P02E2: Intake Air (IA) Flow Valve Control Circuit Low Voltage

DTC P02E3: Intake Air (IA) Flow Valve Control Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open

Short to Voltage

Intake Throttle DC Motor Control 1

P02E3

P02E2

--

Intake Throttle DC Motor Control 2

P02E3

P02E2

--

Circuit/System Description

The intake throttle control motor is installed on the intake throttle valve body together with the position sensor. The intake throttle position sensor changes output voltage according to intake throttle valve position. The intake throttle position sensor provides a signal to the engine control module (ECM) on the signal circuit, which is relative to the position changes of the intake throttle valve.

Conditions for Running the DTC

P02E2

    • The battery voltage is between 10-16 volts.
    • The ignition is ON for longer than 2 seconds.
    • The intake throttle DC motor control command is OFF.

P02E3

    • The battery voltage is between 10-16 volts.
    • The ignition is ON for longer than 2 seconds.
    • The intake throttle actual position less than 1.5 percent.
    • The intake throttle DC motor control command is OFF.

Conditions for Setting the DTC

The ECM detects that the intake throttle motor drive voltage is continuously a high or low condition.

Action Taken When the DTC Sets

DTCs P02E2 and P02E3 are Type A DTCs.

Conditions for Clearing the DTC

DTCs P02E2 and P02E3 are Type A DTCs.

Diagnostic Aids

Inspect for any recent engine mechanical repairs. An incorrectly installed intake throttle valve will cause this DTC to set.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Controls Component Views
    •  Engine Control Module 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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

Verify the integrity of the intake throttle valve by inspecting for the following conditions:

    • Damaged components
    • Loose or improper installation

Circuit/System Testing

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Inspect the intake throttle body for the following conditions:
  2. • A throttle blade that is NOT in the rest position
    • A throttle blade that is binding when opening or closing
    • A throttle blade that is free to move in the open or closed positions WITHOUT spring pressure
    If a condition is found, replace the throttle body.
  3. Ignition ON and the intake throttle harness disconnected, measure for 0 volts on the motor control 1 and 2 circuits.
  4. If the voltage is more than 0 volts, test the affected motor control circuit for a short to voltage. If the circuits test normal, replace the ECM.
  5. Ignition ON, and the intake throttle body harness disconnected, probe the motor control 1 and 2 circuits with a test lamp connected to battery voltage. Verify the test lamp does not illuminate on either circuit.
  6. If the test lamp illuminates, test the affected motor control circuit for a short to ground. If the circuits test normal, replace the ECM.
  7. Ignition ON and the intake throttle connected, clear all DTCs.
  8. Ignition OFF, allow sufficient time for the ECM to power down before disconnecting the intake throttle harness connector.
  9. Using the peak Min Max function, measure the voltage on the motor control 1 circuit as the ignition is turned ON. Voltage should be within 1 volt of ignition voltage.
  10. If voltage is less than the specified range, test the motor control 1 circuit for high resistance. If the circuit tests normal, replace the ECM.
  11. Ignition ON and the intake throttle body connected, clear the DTCs.
  12. Ignition OFF, disconnect the intake throttle and connect a DMM between the motor control 2 circuit and ground.
  13. Using the peak Min Max function, measure the voltage on the motor control 2 circuit as the ignition is turned ON. Voltage should be within 1 volt of ignition voltage.
  14. If voltage is less than the specified range, test the motor control circuit for high resistance. If the circuit tests normal, replace the ECM.
  15. If all circuits test normal, replace the intake throttle.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming