GM Service Manual Online
For 1990-2009 cars only

Object Number: 388517  Size: SF
Cell 20: Power, Ground, MIL, and DLC
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The PCM monitors the EGR valve pintle position input to ensure that the valve responds properly to commands from the PCM. The Linear EGR valve is controlled by using an ignition positive driver and ground circuit within the PCM. The driver has the ability to detect an electrical malfunction in the ignition positive or ground circuit. If an electrical malfunction occurs, the driver signals the PCM to set DTC P0403.

Conditions for Running the DTC

System voltage is between 10.0 volts and 18.0 volts.

Conditions for Setting the DTC

    •  The PCM detects an electrical malfunction in the control circuit for the EGR Valve.
    •  The condition is present for more than 20 second.

Action Taken When the DTC Sets

    • The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure.
    • The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

    • The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using a scan tool.

Diagnostic Aids

Inspect for the follong conditions:

Important: :  Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

    •  Poor terminal connection.
         Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Intermittents and Poor Connections Diagnosis , and Connector Repairs Wiring Systems.
    •  Damaged harness.
         Inspect the wiring harness for damage. If the harness appears to be OK, observe the sensor display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the sensor display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems.
    •  Inspect the PCM and the engine grounds for clean and secure connections.

If the DTC is determined to be intermittent, reviewing the Fail Records can be useful in determining when the DTC was last set.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table:

  1. Listen for an audible click when the solenoid operates. Command the EGR between 0% to 10%. Repeat the commands as necessary.

  2. Verifies that the PCM is providing voltage to the solenoid.

  3. Tests for an open in the ground circuit to the solenoid.

  4. Tests if voltage is constantly being applied to the solenoid.

  5. The PCM utilizes Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.

Step

Action

Value(s)

Yes

No

1

Did you perform the On-Board (OBD) Diagnostic System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn on the ignition, with the engine off.
  2. With a scan tool, command the EGR from 0% to 10%.

Does the solenoid turn on and off with each command?

--

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn off the ignition.
  2. Disconnect the EGR.
  3. Turn on the ignition, with the engine off.
  4. Probe the control circuit of the solenoid with a J 35616-200 test lamp connected to a good ground.
  5. With a scan tool, command the EGR between 0% and 10%.

Does the J 35616-200 test lamp turn on and off with each command?

--

Go to Step 4

Go to Step 5

4

  1. Connect a J 35616-200 test lamp between the control circuit of the solenoid and the ground circuit of the solenoid.
  2. With a scan tool, command the EGR between 0% and 10%.

Does the J 35616-200 test lamp turn on and off with each command?

--

Go to Step 8

Go to Step 10

5

Does the J 35616-200 test lamp remain illuminated with each command?

--

Go to Step 7

Go to Step 6

6

Test the control circuit of the solenoid for a short to ground or an open. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 9

7

Test the control circuit of the solenoid for a short to voltage. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 9

8

Inspect for poor connections at the EGR. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

9

Inspect for poor connections at the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

10

Repair the ground circuit of the solenoid. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 13

--

11

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

Did you complete the replacement?

--

Go to Step 13

--

12

Important: :  The replacement PCM must be reprogramed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Did you complete the replacement?

--

Go to Step 13

--

13

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK