Circuit Description
The engine control module (ECM) controls the exhaust gas recirculation (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 ECM 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 ECM determines that the driver has detected an electrical malfunction on one of these circuits, DTC P0403 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit
Conditions for Running the DTC
| • | The engine is cranking or running. |
| • | The Ignition 1 Signal parameter is between 9-18 volts. |
| • | DTC P0403 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
The ECM detects an electrical malfunction in the EGR solenoid high control circuit or the EGR solenoid low control circuit for more than 10 seconds.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the 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.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the EGR Position Sensor parameter remain within 3 percent of the Desired EGR Position parameter when commanded with a scan tool? | Go to Step 3 | Go to Step 4 |
3 |
Did the DTC fail this ignition? | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections |
4 |
Does the test lamp turn ON at 10 percent and OFF at 0 percent when commanded with a scan tool? | Go to Step 5 | Go to Step 6 |
5 |
Does the test lamp illuminate? | Go to Step 10 | Go to Step 9 |
Does the test lamp remain illuminated when the EGR valve is commanded to 0 percent with a scan tool? | Go to Step 8 | Go to Step 7 | |
7 | Test the EGR solenoid high control circuit for a short to ground or for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 11 |
8 | Test the EGR solenoid high control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 11 |
9 | Test the EGR solenoid low control circuit for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 11 |
10 | 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 . Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
11 | Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
12 | Replace the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement . Did you complete the replacement? | Go to Step 14 | -- |
13 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | -- |
14 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 15 |
15 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |
