P049D

DTC P049D

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 P049D
- Exhaust Gas Recirculation (EGR) Position Not Learned

Circuit/System Description

The offset of the EGR valve is checked after the offset learning has been completed in afterun/post drive. The difference between the maximum and minimum EGR valve offset values is calculated by the Engine Control Module (ECM). If the difference is above a calibrated threshold or the offset learned value is not within a calibrated range, a fault is recognized. While the offset learning is active, the EGR valve is checked for a jammed valve. If the valve is stuck during opening or closing for a calibrated time, a fault is reported. If either of these conditions occur, the DTC will be set.

Conditions for Running the DTC

* DTC P0403, P0405, P0406, or P140F is not set.
* The ignition is OFF and the engine is in afterun/post drive.
* The EGR Valve offset learning procedure is active or complete for current drive cycle.
* The Engine Coolant Temperature (ECT) is between 5-123°C (41-253°F).
* Battery voltage is greater than 10 V.
* The DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

* The ECM detects that the difference between the minimum and maximum EGR valve learned offset values is greater than 30%.
OR
* The ECM detects that the offset learned value for the EGR valve is not within a calibrated range.
OR
* The ECM detects a jammed EGR valve during opening or closing the valve for greater than 5 s.

Action Taken When the DTC Sets

DTC P049D is a Type B DTC.

Conditions for Clearing the DTC

DTC P049D is a Type B DTC.

Reference Information
Schematic Reference

Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
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 (Programming and Relearning)

Circuit/System Verification

Note: Occasionally, when using an EGR device control, Engine Reduced Power and Clean Exhaust Filter messages may occur after a short delay when commanding large EGR positions. The messages are a result of ECM protecting hardware during device control mode. No DTCs will be stored and the Diesel Particulate Filter does not need to be service cleaned. Exiting device control will restore normal function.

1. Ignition ON, observe the scan tool Desired EGR Position and the EGR Position Sensor parameters. Command the EGR valve from 0 to 40 % with a scan tool. The parameters should respond and remain within 3 % throughout the commanded range.
2. Engine running command the EGR Valve to 40 % with a scan tool, then increase the engine speed to 2,500 RPM. The engine should run rough.
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

Note: Perform the Circuit System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, remove the Q14 EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement (Exhaust Gas Recirculation Valve Replacement).
2. 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, replace the Q14 EGR Valve.

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 (Programming and Relearning) for ECM replacement, programming and setup