DTC Descriptors
DTC P0403: Exhaust Gas Recirculation (EGR) Solenoid Control Circuit
Diagnostic Fault Information
Perform the
Diagnostic System Check - Engine Controls
prior to using this diagnostic procedure.
Circuit Description
A voltage is provided to the exhaust gas recirculation (EGR) valve by the ignition 1 voltage circuit through a fuse. Ground is provided to the EGR valve on the control circuit by a low side driver within the engine control module (ECM). The ECM
monitors the voltage on the control circuit of the EGR valve to determine if a failure is present. If ECM detects the voltage on the control circuit of the EGR valve is low while the valve is not commanded or high while the valve is being commanded, DTC P0403
sets.
Conditions for Running the DTC
| • | The engine is operating. |
| • | The ignition 1 voltage is more 10 volts. |
| • | DTC P0403 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
The ECM detects the voltage on the control circuit of the EGR valve is low while the valve is not commanded or high while the valve is being commanded for 25 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. |
Diagnostic Aids
Test the EGR valve for the following:
Excessive deposits on the EGR valve pintle that may interfere with the EGR valve pintle extending completely or cause the pintle to stick. Refer to
Exhaust Gas Recirculation Valve Replacement
.
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
- Engine idling, observe the DTC information with a scan tool. DTC P0403 should not set.
- If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector of the EGR valve.
- Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit and ground.
| ⇒ | If the test lamp does not illuminate, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition 1 circuit fuse is open, test all components connected
to the ignition 1 voltage circuit and replace as necessary. |
- Test for 3.0-4.5 volts between the control circuit and ground.
| ⇒ | If less than 3.0 volts, test the control circuit for a short to ground or open/high resistance. If the circuit/connections test normal, replace the ECM. |
| ⇒ | If greater than 4.5 volts, test the control
circuit for a short to voltage. If the circuit/connections test normal, replace the ECM. |
- Ignition OFF, connect a 5-amp fused jumper wire between the ignition 1 terminal of the solenoid and B+.
- Connect a jumper wire between the EGR valve control terminal of the solenoid.
- Start the engine and ground the EGR valve control terminal. The engine should stall, run rough, or engine speed will change.
| ⇒ | If the engine does not stall, replace the EGR valve. |
- If all circuits/connections test normal, replace the ECM.
Component Testing
- Ignition OFF, disconnect the harness connector of the EGR valve.
- Measure for 6-10 ohms of resistance between the terminals of the EGR valve.
| ⇒ | If the resistance is out of the specified range, replace the EGR valve |
Repair Instructions
