GM Service Manual Online
For 1990-2009 cars only

Object Number: 1350460  Size: MF
Engine Controls Component Views
Engine Controls Schematics
Engine Controls Schematic Icons

Circuit Description

The DTC P0403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit diagnostic detects faults in the EGR valve electrical circuit. The powertrain control module (PCM) controls the EGR valve with a solid state device called a driver. The driver supplies the EGR solenoid with 12 volts that is pulse width modulated (PWM) through the EGR solenoid high control circuit. A ground path is provided by the PCM through the EGR solenoid low control circuit. The driver has the ability to detect an electrical malfunction on the EGR solenoid control circuits. If the PCM determines that the driver has detected an electrical malfunction on one of these circuits, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC.

DTC P0403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit

Conditions for Running the DTC

    • DTC P0030, P0050, P0097, P0098, P0107, P0108, P0117, P0118, P0135, P0155, P0335, P0336, P0401, P0404, P0406, P0641, P0651, P1128, P1129, P2238, P2239, P2241, P2242, P2243, P2245, P2247, P2249, P2252, P2253, P2255, P2256, P2413, P2414, P2415, P2630, and P2631 are not set.
    • The engine is running.
    • The EGR is operating between 2-98 percent duty cycle.
    • DTC P0403 runs continuously once the above conditions have been met.

Conditions for Setting the DTC

    • The PCM detects an electrical malfunction in the EGR solenoid control circuit.
    • The above condition is present for more than 5 seconds.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step checks for an open in the EGR solenoid control circuit. The PCM provides a 12 volt bias signal on the solenoid control circuit that is pulled low when the solenoid is OK and has a good ground.

  2. This step tests whether the PCM is actually commanding ON the EGR valve.

  3. After replacing the PCM a new minimum throttle position and idle speed must be established.

Step

Action

Values

Yes

No

Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Start and run the engine until the coolant temperature is 85°C (185°F).
  2. Command the EGR from 0 percent to 100 percent with a scan tool. Refer to Scan Tool Output Controls .
  3. Observe the EGR position sensor parameter with the scan tool.

Is the EGR Sensor parameter within the specified value?

3.0-3.2 V

Go to Step 3

Go to Step 4

3

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Intermittent Conditions

4

  1. Turn OFF the ignition.
  2. Disconnect the EGR valve.
  3. Measure the resistance of the EGR solenoid with a DMM.

Is the solenoid resistance within the specified value?

6.3-7.0 ohms at 20°C (68°F)

Go to Step 5

Go to Step 11

5

  1. Connect the DMM to the EGR solenoid control circuit and ground.
  2. Turn ON the ignition, with the engine OFF.

Is the voltage near the specified value?

12 V

Go to Step 6

Go to Step 7

6

  1. Connect a test lamp between the EGR solenoid control circuit and the EGR solenoid ground circuit.
  2. Command the EGR valve from 0-100 percent with the scan tool.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 8

7

Test the EGR solenoid high control circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

8

Test the EGR solenoid ground circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct a condition?

--

Go to Step 13

Go to Step 12

9

Test for an intermittent and for a poor connection at the EGR valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

10

Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

11

Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement .

Did you complete the replacement?

--

Go to Step 13

--

12

  1. Replace the PCM. Refer to Powertrain Control Module Replacement .
  2. Perform the idle learn procedure. Refer to Idle Learn .

Did you complete the replacement?

--

Go to Step 13

--

13

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 14

14

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK