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 a ground circuit located within the PCM. The PCM monitors the ignition positive driver circuit and has the ability to detect an electrical malfunction. If the PCM detects an electrical malfunction, DTC P0403 is set.
Conditions for Running the DTC
| • | None of the following DTCs are set: |
| • | Throttle position (TP) sensor DTCs |
| • | Vehicle speed sensor (VSS) DTCs |
| • | Intake air temperature (IAT) sensor DTCs |
| • | Manifold absolute pressure (MAP) sensor DTCs |
| • | Engine coolant temperature (ECT) sensor DTCs |
| • | Crankshaft position (CKP) sensor DTCs |
| • | Mass air flow (MAF) sensor DTCs |
| • | Idle speed DTCs |
| • | Misfire DTCs |
| • | Fuel injector fault DTCs |
| • | The system voltage is between 10 and 16 volts. |
Conditions for Setting the DTC
| • | The 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 illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has run and failed. |
| • | The PCM disables the EGR for the ignition cycle. |
| • | The PCM stores the conditions which were present when the DTC set as Freeze Frame and Fail Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns the MIL off during the third consecutive trip in which the diagnostic has run and passed. |
| • | The history DTC clears after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC may be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed. |
Diagnostic Aids
Inspect for the following conditions:
| • | A faulty connection at the PCM or the EGR valve. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connections. |
| • | Inspect the wiring harness for damage. If the harness appears to be OK, connect a digital multimeter (DMM) and test the circuit continuity while moving the connectors and wiring harnesses related to the EGR valve. A change in the display indicates the location of the malfunction. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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Listen for an audible click when the solenoid operates. Command the EGR between 0% to 10%. Repeat the commands as necessary.
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Verifies that the PCM is providing voltage to the solenoid.
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Tests for an open in the ground circuit to the solenoid.
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Tests if voltage is constantly being applied to the solenoid.
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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 | |
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 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 Repairing Connector Terminals 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 Repairing Connector Terminals 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 | -- |
|
Important: Perform the set up procedure for the PCM. 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 |
