P046C

DTC P046C

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P046C

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Exhaust Gas Recirculation (EGR) Position Sensor Performance

Diagnostic Fault Information






Typical Scan Tool Data






Circuit/System Description

The engine control module (ECM) uses the exhaust gas recirculation (EGR) position sensor to determine the position of the EGR valve. The ECM sends a reference voltage through the 5-volt reference circuit to the EGR position sensor. The ECM provides a voltage return path for the sensor through the low reference circuit. A variable voltage signal, based on the EGR valve position, is sent from the sensor to the ECM through the EGR position sensor signal circuit. The ECM compares the actual EGR position with the desired EGR position when the EGR valve is commanded open or closed.

The EGR valve is controlled by the ECM through the EGR motor high control and the EGR motor low control circuits. The ECM supplies voltage that is near ignition voltage to the high and low control circuits at all times. The ECM will pulse width modulate the low control circuit to ground when EGR is desired. The lower the pulse width, the more the valve will open. The ECM will pulse width modulate the high control circuit to ground when the EGR valve is desired closed.

Conditions for Running the DTC

* Engine speed is greater than 600 RPM.

* The Battery voltage is greater than 11 V.

* The Air Intake Heater duty cycle is less than 5 %.

* The EGR Valve is active.

* The EGR Valve offset learning from the previous drive cycle is complete.

* EGR offset learning is not active.

* DTC P046C runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the difference between the actual EGR position and the desired EGR position is greater than 5 % or less than -5 % for greater than 8 s.

Action Taken When the DTC Sets

DTC P046C is a Type B DTC.

Conditions for Clearing the DTC

DTC P046C is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics [1][2]Electrical Diagrams

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, observe the scan tool DTC information. Verify DTC P0403, P0406, or P06A3 is not set.

• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

2. Ignition ON, observe the scan tool Desired EGR Position and the EGR Position Sensor parameters. Command the EGR valve from 0-40 % with a scan tool. The parameters should increment and remain within 3 % throughout the commanded range.

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.

Circuit/System Testing

Ignition OFF, remove the Q14 EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement Exhaust Gas Recirculation Valve Replacement. Inspect the Q14 EGR valve for the following conditions:

* A sticking, binding or frozen EGR valve

* Any coking, soot build up, debris or damage that can cause the EGR valve to stick partially open or closed

• If a condition is found, clean or replace the Q14 EGR Valve as necessary.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Exhaust Gas Recirculation Valve Replacement Exhaust Gas Recirculation Valve Replacement

* Control Module References Control Module References for ECM replacement, setup and programming