Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
DTC Descriptors
DTC P0403: Exhaust Gas Recirculation (EGR) Solenoid Control CircuitDTC P0404: Exhaust Gas Recirculation (EGR) Open Position Performance
DTC P0405: Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage
DTC P0406: Exhaust Gas Recirculation (EGR) Position Sensor Circuit High Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ignition 1 Voltage | P0403 | P0404 | P0643 | -- |
5-Volt Reference | P0106, P0404, P0405, P0462, P0642, P2077 | P0404, P0405 | -- | -- |
EGR Position Sensor Signal | P0403, P0405 | P0403, P0406 | P0403, P0406 | -- |
EGR Solenoid Control | P0403, P0404 | P0403 | P0403, P0404 | -- |
Low Reference | -- | P0404, P0406 | -- | -- |
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine operating in Closed Loop Parameter Normal Range: 0.6-0.8 Volts | |||
Ignition 1 Voltage | -- | -- | -- |
5-Volt Reference | 0.2 Volts | 0.1 Volts | 0.7 Volts |
EGR Position Sensor Signal | 0 Volts | 5 Volts | 5 Volts |
EGR Solenoid Control | 4.6 Volts | -- | -- |
Low Reference | -- | 5 Volts | -- |
Circuit Description
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.
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 utilizes the following circuits:
| • | An ignition 1 voltage circuit |
| • | A 5-volt reference circuit |
| • | An EGR solenoid control circuit |
| • | A signal circuit |
| • | A low reference circuit |
Conditions for Running the DTC
P0403
| • | Ignition is ON or the engine is running |
| • | The ignition voltage is between 9-25 volts. |
| • | The DTC runs continuously once the above conditions are met. |
P0404
| • | DTCs P0400, P0401, P0403, P0405, and P0406 are not set. |
| • | Engine is running. |
| • | Engine speed is between 1,696-2,592 RPM. |
| • | Calculated airflow is between 49-191 kg/h. |
| • | Engine coolant temperature is greater than 70°C (158°F). |
| • | The DTC runs continuously once the above conditions are met. |
P0405, and P0406
| • | Ignition is ON or the engine is running |
| • | The DTCs run continuously once the above conditions are met. |
Conditions for Setting the DTC
P0403
The ECM detects an open, short to ground or voltage on the control circuit of the EGR valve for greater than 10 seconds.
P0404
The ECM detects the low limit learned value of the EGR position sensor is less than 0.1 volt or greater than 1.7 volts for greater than 20 seconds.
P0405
The ECM detects the EGR position sensor is less than 0.3 volt for greater than 20 seconds.
P0406
The ECM detects the EGR position sensor is greater than 4.6 volts for greater than 20 seconds.
Action Taken When the DTC Sets
DTCs P0403, P0405, and P0406 are Type A DTCs.
DTC P0404 is a Type B DTC.
Conditions for Clearing the DTC
DTCs P0403, P0405, and P0406 are Type A DTCs.
DTC P0404 is a Type B DTC.
Diagnostic Aids
If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected.
Reference Information
Schematic Reference
Connector End View Reference
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
Circuit/System Verification
- Ignition ON, observe the DTC information with a scan tool. Verify DTCs P0642 or P0643 are not set.
- Observe the scan tool EGR position sensor voltage parameter. The reading should be between the range 0.6-0.8 Volts.
- Command the EGR valve ON with a scan tool . The scan tool EGR position sensor voltage should fluctuate between 0.6-4.3 Volts.
- 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.
| ⇒ | If DTC P0642 or P0643 is set, refer to DTC P0642, P0643, P0698, or P0699 . |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the EGR valve.
- Test for less than 5 ohms of resistance between the low reference circuit and ground.
- Ignition On, test for B+ between the ignition 1 voltage circuit and ground.
- Test for 4.8-5.2 volts between the 5-volt reference circuit and ground.
- Connect a test lamp between the control circuit and B+.
- Command the EGR valve ON with a scan tool. Verify there is less than 1 volt between the control circuit and ground.
- Verify the scan tool EGR position sensor parameter is greater than 4.9 volts.
- Install a 3-A fused jumper wire between the signal circuit and the low reference circuit. Verify the EGR position sensor parameter is less than 0.2 volt.
- If all circuits test normal, test or replace the EGR valve.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than B+, test the ignition 1 voltage circuit for a short to ground or an open/high resistance. |
Important: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.
| ⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
| ⇒ | If test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. |
Important: Voltage fluctuation is normal.
| ⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
Component Testing
- Ignition OFF, disconnect the harness connector at the EGR valve.
- Test for 6-12 ohms of resistance between the ignition 1 voltage terminal and control circuit terminal.
| ⇒ | If not within the specified range, replace the EGR valve. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for engine control module replacement, setup, and programming |
