What Does It Mean?
This is a generic powertrain diagnostic trouble code (DTC) that applies to OBD-II vehicles. This may include, but is not limited to, vehicles from Ford, Chevrolet/GM/Cummins, Dodge/Ram, Isuzu, Pontiac, Toyota, BMW, Mercedes, etc. Although generic, the exact repair steps may vary depending on the year, make, model, and powertrain configuration.
If your vehicle has stored a P045E code, it means the Powertrain Control Module (PCM) has detected a problem with the Exhaust Gas Recirculation (EGR) valve control system.
In the case of P045E, the valve appears (to the PCM) to be stuck in the open position. The designation “B” applies to a specific position or stage of the lowered EGR valve control system, which is explained below.
The EGR system is responsible for allowing the engine to consume some of the unburned fuel from the exhaust system. The EGR system is necessary to reduce harmful levels of nitrogen oxides (NOx) created as a byproduct of gasoline and diesel engine operation.
The focal point of the EGR system is an electronically controlled valve (EGR) that opens to allow exhaust gases to re-enter the engine’s intake. The PCM uses input signals from the Throttle Position Sensor (TPS), Vehicle Speed Sensor (VSS), and Crankshaft Position Sensor (CKP) to determine when conditions are suitable for opening/closing the EGR valve.
Vehicles that exhibit this type of code are equipped with a lowered EGR valve. The lowered EGR valve operates in stages depending on the degree of throttle opening, the amount of load placed on the engine, and the speed at which the vehicle is traveling.
In some models, the position of the EGR valve piston is also monitored by the PCM. If the desired position of the EGR valve (as commanded by the PCM) is different from the actual position, a P045E code will be stored and a Malfunction Indicator Lamp (MIL) may illuminate. Most vehicles will require several ignition cycles (with a fault) before the MIL illumination occurs.
Photo of the Exhaust Gas Recirculation (EGR) Valve:
P045E EGR Valve
How Severe Is This DTC?
The conditions that lead to a stored P045E code can also cause serious driving issues. For this reason, a P045E code should be addressed urgently.
What Are Some of the Symptoms of the Code?
Symptoms of a P045E fault code can include:
Irregular engine idle
Reduced fuel efficiency
Excessively lean exhaust
Other driveability codes may be stored
What Are Some of the Common Causes of the Code?
Causes
of this P045E code can include:
Faulty EGR valve
EGR valve piston clogged with carbon or other debris
Faulty EGR control solenoid/valve
Open or shorted wiring/connectors in the EGR B control circuit
Faulty DPFE sensor
Faulty EGR valve position sensor
PCM malfunction or PCM programming error
What Are the P045E Troubleshooting Steps?
A diagnostic scanner, a digital volt/ohmmeter, and a reliable source of vehicle information are among the tools needed to diagnose a P045E code.
A visual inspection of all wiring and connectors related to the EGR system is an ideal precursor to diagnosing a P045E code. Repair or replace any corroded or burnt components as necessary.
Continue by connecting the scanner to the diagnostic port and retrieving all stored codes and freeze frame data. Note all of this information as it will prove useful if the P045E is an intermittent code. Now, clear the codes and test drive the vehicle to see if the code resets.
If the code resets, connect the scanner and observe the data stream. Check the desired EGR position (usually measured as a percentage) and the actual EGR position, as shown on the data stream display. Within milliseconds, they should be identical. If the actual EGR position indicates it is open too far, suspect that a piece of carbon has clogged the piston opening or that the EGR valve is faulty.
Obviously, the simplest method to inspect the EGR plunger would be to remove the valve and take a look. Unfortunately, the location of the EGR valve on some models makes the removal (and reinstallation) of the EGR valve less than convenient. If the EGR valve can be easily removed for inspection, this would be my first step (especially if the vehicle in question has over 100,000 km). Carbon fouling and clogged passages are fairly common issues for high-mileage vehicles. If the piston appears to be obstructed, remove the blockage and test the EGR system again.
If no obstruction is discovered in the EGR valve piston opening, follow the manufacturer’s recommendations for testing the EGR actuator solenoids with the DVOM. Lowered EGR valves may use multiple solenoids to affect the full spectrum of EGR system operation.
If the EGR system for the vehicle in question uses an EGR valve position sensor, it is likely integrated into the valve itself. Follow the manufacturer’s recommendations, along with connector pinout charts and vehicle wiring diagrams found in your vehicle information source, to test individual components. Replace faulty parts as needed and test the system again.
The DVOM can be used to test individual circuits between the PCM connector and the EGR valve connector. All associated controllers must be disconnected from the circuit before testing begins.
Carbon deposits are caused by the high levels of detergent found in modern fuels.
Once repairs are made, allow the PCM to enter readiness mode before assuming they were successful.