Spark

DTC P0403-P0406 or P042E - Without FX3

Voltage is provided to the exhaust gas recirculation (EGR) valve by the ignition 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.

The ECM monitors the position of the EGR valve through the EGR valve position sensor. The EGR valve position sensor sends a feedback voltage on the signal circuit to the ECM. The EGR position sensor voltage varies depending on the position of the EGR valve.

The EGR valve utilises the following circuits:

P0403, P0405, or P0406

P0404 (TEST 1)

P0404 (TEST 2)

P0403

The ECM detects a short circuit to battery, a short circuit to ground, or an open circuit on the EGR solenoid control circuit.

P0404 (TEST 1)

The ECM detects that the learned value of the EGR position sensor is less than 0.1613 V or greater than 4.9756 V.

P0404 (TEST 2)

The ECM detects that the EGR solenoid pulse width modulation control limit is out of range.

P0405

The ECM detects that the EGR position sensor signal voltage is less than 0.0342 V

P0406

The ECM detects that the EGR position sensor signal voltage is greater than 4.8904 V.

DTC P0403, P0404, P0405, and P0406 are Type E DTCs.

DTC P0403, P0404, P0405, and P0406 are Type E DTCs.

If a shared 5 V reference circuit is shorted to ground or shorted to a voltage, other 5 V reference circuits may be affected.

Schematic Reference

Engine Controls Schematics : Siemens ECM - LPG with LCP → Siemens ECM - Gas without FX3 or LCP → Delphi ECM - FX3

Connector End View Reference

Component Connector End Views

Description and Operation

Exhaust Gas Recirculation (EGR) System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Note: The scan tool EGR position sensor parameter will display less than 5 V when the EGR is commanded to 100%.

1. Ignition ON, verify that the scan tool EGR Position Sensor parameter is greater than 4.0 V while commanding the EGR valve to 100%.
2. Engine running, verify that the scan tool EGR Position Sensor parameter is less than 1.0 V.
3. Operate the vehicle within the Conditions For Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the Q14 Exhaust Gas Recirculation (EGR) Valve.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal E and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse F6UB is open, test all components connected to the ignition circuit and replace as necessary.

3. Connect a test lamp between the control circuit terminal A and the ignition circuit terminal E.
4. Command the EGR solenoid valve from 0-100% with a scan tool. The test lamp should respond to the scan tool commands.

⇒	If test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

5. Ignition OFF, test for less than 1 Ω between the low reference circuit terminal B and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

6. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal D and ground.

⇒	If less than the specified range, test the 5 V reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

7. Verify the scan tool EGR position sensor parameter is greater than 4.8 V.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

8. Install a 3A fused jumper wire between the signal circuit terminal C and the low reference circuit terminal B. Verify the scan tool EGR Position Sensor parameter is less than 0.2 V.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

9. If all circuits test normal, test or replace the Q14 Exhaust Gas Recirculation (EGR) Valve.

1. Ignition OFF, disconnect the harness connector at the Q14 Exhaust Gas Recirculation (EGR) Valve.
2. Test for 6-10 Ω of resistance between the ignition terminal E and control terminal A.

⇒	If not within the specified range, replace the Q14 Exhaust Gas Recirculation (EGR) valve.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.