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 provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0405: Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low VoltageDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
5 Volt Reference | P0641, P0532, P0452, P0107 | P0405 | P0641 | -- |
Sensor Signal | P0405 | P0405 | P0406 | P0404, P042E |
Low Reference | -- | P0406 | -- | -- |
EGR Solenoid High Control | -- | P0403 | P0403 | -- |
EGR Solenoid Low Control | -- | P0403 | -- | -- |
Circuit Description
The control module tests the exhaust gas recirculation (EGR) system during deceleration. The control module does this by momentarily commanding the EGR valve to open while monitoring the signal circuit of the manifold absolute pressure (MAP) sensor. When the EGR valve is opened, the control module will expect to see a predetermined increase in MAP. If the expected increase in MAP is not detected, the control module records the amount of MAP difference that was detected and adjusts a calibrated fail counter towards a calibrated fail threshold level. The number of EGR flow test counts required to exceed the fail threshold may vary according to the amount of detected EGR flow error.
The EGR valve position sensor is monitored by the control module. The 5-volt reference circuit, the low reference circuit, and the EGR valve position signal circuit are used by the control module to determine the EGR valve position. The control module compares the EGR Position Sensor parameter with the desired EGR Position parameter when the valve is commanded open or closed.
The control module controls the 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 control module through the EGR solenoid low control circuit. The driver has the ability to detect an electrical malfunction on the EGR solenoid control circuits.
When the ignition switch is turned ON, the control module records the EGR Learned Minimum Position. The control module compares the EGR Learned Minimum Position parameter to the EGR Position Sensor parameter.
The control module is able to determine if the EGR valve position sensor signal voltage is too low.
Conditions for Running the DTC
| • | DTC P0641 or P0651 are not set. |
| • | The EGR flow test is not running. |
| • | The Ignition 1 Signal parameter is more than 11 volts. |
Conditions for Setting the DTC
| • | The EGR Position Sensor parameter is less than 4 percent of the 5-volt reference. |
| • | The above condition is met for more than 55 seconds. |
Action Taken When the DTC Sets
DTC P0405 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0405 is a Type B DTC.
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
Important: If DTC P0641 or P0651 are also set, diagnose those DTCs first.
| • | With the ignition ON and the engine OFF, command the EGR from 0-90 percent. The EGR Position Sensor parameter should remain within 3 percent of the Desired EGR Position parameter through the entire range. |
| • | 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 list. |
Circuit/System Testing
Important: You must complete the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, disconnect the EGR valve harness connector.
- Test for less than 5 ohms of resistance between the low reference circuit and ground.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit and ground.
- Verify the EGR Position parameter is less than 1 percent.
- Install a 3A fused jumper wire between the signal circuit and the 5-volt reference circuit . The EGR Position Sensor parameter should display more than 90 percent.
- If all circuits test normal, replace the EGR Valve.
| ⇒ | If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground, short to EGR control circuits or an 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 greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
| ⇒ | 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 ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
