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DTC P0404-P0406 — LNP or LNQ

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 Descriptors

DTC P0404 00: Exhaust Gas Recirculation (EGR) Open Position Performance

DTC P0405 00: Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage

DTC P0406 00: Exhaust Gas Recirculation (EGR) Position Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Control

P1407 00

P0404 00

P1407

P0404 00

Ground

-

P0405 00

-

P0404 00

Circuit/System Description

The exhaust gas recirculation (EGR) valve is controlled by the engine control module (ECM) through the EGR solenoid. A reference voltage is supplied to the EGR valve solenoid. The ECM controls the solenoid by grounding the control circuit.

Conditions for Running the DTC

    • The ignition is ON or the engine is running.
    • The DTCs run continuously when the above conditions are met.

Conditions for Setting the DTC

P0404 00

The ECM detects a stuck valve.

P0405

The EGR position sensor voltage is less than 0.26 V for more than 1 s.

P0406

The EGR position sensor voltage is more than 4.75 V for more than 3 s.

Action Taken When the DTC Sets

DTCs P0404 00, P0405 00, and P0406 00 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0404 00, P0405 00, and P0406 00 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON, observe the scan tool EGR Position Sensor parameter. The reading should be between 0.25-4.75 V.
  2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the Q14 Exhaust Gas Recirculation Valve.
  2. Ignition OFF, test for less than 5 Ω between the low reference circuit terminal 3 and ground.
  3. 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.
  4. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.
  5. If less than the specified range, test the 5 V reference circuit for a short to ground or an 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.
  6. Verify the scan tool EGR Position Sensor parameter is less than 0.3 V.
  7. If greater than the specified range, test the signal circuit terminal 5 for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.
  8. Install a 3 A fused jumper wire between the signal circuit terminal 5 and the 5 V reference circuit terminal 1. Verify the scan tool EGR Position Sensor parameter is greater than 4.8 V.
  9. If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
  10. If all circuits test normal, test or replace the Q14 Exhaust Gas Recirculation Valve.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Exhaust Gas Recirculation Valve Replacement
    • Control Module References for ECM replacement, setup, and programming
   


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