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 Descriptor

DTC P02E0: Diesel Intake Air (IA) Flow Control Circuit

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

IA Flow Valve 5-Volt Reference Voltage

P0642

P02E9

P02E8

P0336, P0643

IA Flow Valve Sensor Signal

P02E8

P02E7

P02E8

P02E9

IA Flow Valve Low Reference

--

P02E7

P02E8, P02E9

--

IA Flow Valve Motor Control 1

P02E0

--

P02E0

P02E0

IA Flow Valve Motor Control 2

P02E0

--

P02E0

P02E0

Circuit/System Description

The intake air (IA) valve is a normally open valve and is only operated during a DPF regeneration. The position of the IA valve is controlled by the engine control module (ECM). The IA valve system uses a position sensor located within the valve assembly to monitor the position of the valve. The position sensor has the following circuits:

    • 5-volt reference circuit
    • Low reference circuit
    • Signal circuit

The IA valve uses a motor to move the valve to a closed position and spring tension returns it to the open position. The motor has the following circuits:

    • Motor control 1 circuit
    • Motor control 2 circuit

Conditions for Running the DTC

    • The ECM is powered up for more than 0.5 second.
    • The IA valve duty cycle is greater than 10 percent.
    • DTC P02E0 runs continuously.

Conditions for Setting the DTC

    • The IA valve duty cycle is greater than 10 percent.
    • The IA valve control circuit is less than 25 mA.

Action Taken When the DTC Sets

    • DTC P02E0 is a Type B DTC.
    • Diesel particulate filter (DPF) regeneration is inhibited.

Conditions for Clearing the DTC

DTC P02E0 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. Command the IA valve from 100 percent to 0 percent. The IAF Valve Commanded Position and the IAF Valve Position parameter should match.
  2. After the engine has been running, turn OFF the ignition. Observe the IA Valve Position parameter fluctuates between 0 percent and 100 percent several times.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. With the ignition OFF, disconnect the ECM and the IAF valve. Test the following circuits for a short to voltage, short to ground, or open/high resistance:
  2. • AI Motor Control 1 circuit terminal A
    • AI Motor Control 2 circuit terminal B
         ⇒If a condition is found repair the affected circuit.
  3. Connect the ECM. Ignition ON, and the IAF disconnected, measure for 12 volts between the following circuits and ground:
  4. • IA Motor Control 1 circuit terminal A
    • IA Motor Control 2 circuit terminal B
         ⇒If voltage is less than 12 volts on either circuit, replace the ECM.
         ⇒If the voltage is 12 volts on both circuits, replace the IAF valve.

Repair Instructions

    •  Intake Air Valve Replacement
    •  Control Module References for ECM replacement, setup and programming

Repair Verification

  1. Install any components or connectors that have been removed or replaced during diagnosis.
  2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
  3. Clear the DTCs.
  4. Turn OFF the ignition for 90 seconds.
  5. Duplicate the Conditions for Running the DTC and use the Freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
  6. Perform the Diesel Particulate Filter (DPF) Service Regeneration.