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 P245A 00: Exhaust Gas Recirculation (EGR) Cooler Bypass Control Circuit Open

DTC P245B 00: Exhaust Gas Recirculation (EGR) Cooler Bypass Solenoid Valve Control Circuit Malfunction

DTC P245C 02: Exhaust Gas Recirculation (EGR) Cooler Bypass Solenoid Valve Control Circuit Short to Ground

DTC P245D 01: Exhaust Gas Recirculation (EGR) Cooler Bypass Solenoid Valve Control Circuit Short to Battery

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ignition

P245A 00

P245A 00

--

--

Output Control

P245C 02

P245A 00

P245D 01

P245B 00

Circuit/System Description

The exhaust gas recirculation (EGR) cooler bypass solenoid valve is controlled by the engine control module (ECM). At engine cold start, the EGR cooler bypass allows hot exhaust gas to heat the intake air in the manifold. Once the engine operating temperature is reached, the ECM will close the EGR cooler bypass.

Conditions for Running the DTC

Ignition is on.

Conditions for Setting the DTC

P245A 00

The ECM detects an open in the output circuit.

P245B 00

The ECM detects a high resistance at the output circuit.

P245C 02

The ECM detects a short to ground at the output circuit.

P245D 01

The ECM detects a short to battery at the output circuit.

Action Taken When the DTC Sets

DTCs P245A-P245D are Type C DTCs

Conditions for Clearing the DTC

DTCs P245A-P245D are Type C DTCs

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

Special Tools

J 23738-A Mityvac

For equivalent regional tools, refer to Special Tools.

Circuit/System Verification

  1. Disconnect the vacuum source from the EGR Cooler Bypass valve.
  2. Connect the J 23738-A Mityvac to the EGR Cooler Bypass valve vacuum supply hose. Engine running, verify the vacuum is greater than -50 kPa (-7.25 PSI).
  3. If less than the specified range, inspect the vacuum supply hose and filter for a leak or restriction. If the supply hose is normal, replace the vacuum pump.
  4. Connect the vacuum source to the EGR Cooler Bypass valve. Connect the J 23738-A Mityvac to the EGR Cooler Bypass valve vacuum port on the EGR Cooler Bypass valve. Engine running, command the EGR Cooler Bypass valve OFF with a scan tool. Verify the vacuum is at 0 kPa (0 PSI).
  5. If greater than the specified range, replace the EGR Cooler Bypass valve.
  6. Command the EGR Cooler Bypass valve ON with a scan tool. Verify the vacuum is greater than -50 kPa (-7.25 PSI).
  7. If less than the specified range, replace the EGR Cooler Bypass valve.
  8. If all other components test normal, test or replace the EGR Cooler Bypass valve.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the EGR Cooler Bypass valve.
  2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 2 and ground.
  3. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the EGR Cooler Bypass valve.
  4. Verify that a test lamp does not illuminate between the ignition circuit terminal 2 and the control circuit terminal 1.
  5. If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).
  6. Command the EGR Cooler Bypass valve ON with a scan tool. Verify the test lamp corresponds to the commanded states of the scan tool.
  7. If the test lamp is always off, test the control circuit for an open circuit or short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM).
  8. If all circuits test normal, test or replace the EGR Cooler Bypass valve.

Component Testing

Static Test

  1. Ignition OFF, disconnect the harness connector at the EGR Cooler Bypass valve.
  2. Test for 1.2-3.5 Ω between the control terminal 1 and the ignition terminal 2 of the EGR Cooler Bypass valve.
  3. If not within the specified range, replace the EGR Cooler Bypass valve.
  4. Test for infinite resistance between each terminal and the EGR Cooler Bypass valve case.
  5. If not the specified value, replace the EGR Cooler Bypass valve.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Exhaust Gas Recirculation Valve Cooler Replacement