Circuit Description
The powertrain control module (PCM) monitors the exhaust gas recirculation (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 can detect an electrical malfunction in the control circuit. If an electrical malfunction occurs DTC P0403 will set.
Conditions for Running the DTC
The system voltage is between 9 and 16 volts.
Conditions for Setting the DTC
| • | The PCM detects an electrical malfunction in the control circuit for the EGR valve. |
| • | The above condition is present for more 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/Failure Records data. |
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 following conditions.
Many situations may lead to an intermittent condition. Perform each inspection or test as directed.
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.
| • | Loose terminal connection |
| - | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| - | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair. |
| • | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
| • | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair. |
If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Listen for a click when the solenoid operates. Command the EGR between 0 percent to 10 percent. Repeat the commands as necessary.
-
This step verifies that the PCM is providing voltage to the solenoid.
-
This step tests for an open in the ground circuit to the solenoid.
-
This step tests if the voltage is constantly being applied to the solenoid.
-
The PCM utilizes an electrically Eerasable Pprogrammable read-only memory (EEPROM). When you replace the PCM, you must program the new PCM..
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the On Board (OBD) Diagnostic System Check? | -- | Go to Step 2 | |
Does the solenoid turn ON and OFF with each command? | -- | Go to Diagnostic Aids | Go to Step 3 | |
Does the test lamp turn ON and OFF with each command? | -- | Go to Step 4 | Go to Step 5 | |
Does the test lamp turn ON and OFF with each command? | -- | Go to Step 8 | Go to Step 10 | |
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 for an open. If you find a problem, repair the condition as necessary. 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. If you find a problem, repair the condition as necessary. 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 Testing for Intermittent Conditions and Poor Connections . If you find a problem, repair the condition as necessary. Refer to 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 Testing for Intermittent Conditions and Poor Connections . If you find a problem, repair the condition as necessary. Refer to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 |
10 | Test the ground circuit and the PCM connector for an open, and repair the condition as necessary. Refer to Wiring Repairs . Did you find and correct a problem? | -- | 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 | -- |
|
Important: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Did you complete the replacement? | -- | Go to Step 13 | -- | |
13 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
