For 1990-2009 cars
Engine Controls Components
Engine Controls Schematics
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 above 10 volts.

### Conditions for Setting the DTC

• | EGR Feedback is 0.4 volt greater than the EGR Closed Valve Pintle Position when the Desired EGR Position is commanded to 0%

• | The above condition is present for longer than 20 seconds.

### Action Taken When the DTC Sets

• | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.

• | The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been 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 the scan tool.

### Diagnostic Aids

• | Poor connection at PCM or EGR Valve.

| Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wore connection.

• | Damaged harness.

| Inspect the wiring harness for damage. If the harness appears to be OK, connect J 39200 DMM and check circuit continuity while moving connectors and wiring harnesses related to the EGR valve. A change in the display will indicate the location of the malfunction.

### 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 test lamp connected to a good ground.
5. With a scan tool, command the EGR between 0% and 10%.

Does the test lamp turn ON and OFF with each command?

--

Go to Step 4

Go to Step 5

4 |

1. Connect a 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 test lamp turn ON and OFF with each command?

--

Go to Step 8

Go to Step 10

5 | Does the 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 . 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 . 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 . 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 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Important: Perform the set up procedure for the PCM. 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