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Error Code P045E is defined as Exhaust Gas Recirculation B Control Stuck Open.
This code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II, especially those made from 1996 up to the present. These vehicles may include (but are not limited to) Vehicle brands may include (but are not limited to) Ford, Chevrolet, GM, Cummins, Dodge, Ram, Isuzu, Pontiac, Toyota, BMW, Mercedes, etc. Specifications on the definition, troubleshooting, and repairs, of course, vary from one make and model to another.
Error Code P045E means the PCM (powertrain control module, also known as ECM or engine control module in other vehicle makes) has determined a problem in the EGR (exhaust gas recirculation) valve control system, as it appears to be stuck in open position. Designation “B” applies to a specific position or stage of the step-down EGR valve control system.
The EGR works by allowing the engine to consume a part of the unburned fuel from the exhaust system; it’s an important system to lessen harmful NOx (Nitrogen Oxide) levels which is a byproduct of gasoline and diesel operation.
The EGR’s focal point is the electronically controlled EGR valve, which allows exhaust gas to re-enter the engine intake. The TPS (Throttle Position Sensor), VSS(Vehicle Speed Sensor), and CKP (Crankshaft Position Sensor) send input signals to the PCM, which the latter uses to determine when the conditions are right to open/close the EGR valve.
Vehicles with this kind of system also come with a step-down EGR valve, which operates in stages according to the degree which the throttle is opened, the load of the engine, and the speed of the vehicle.
In other models, the PCM also monitors the position of the EGR valve plunger. If the desired position (as directed by the PCM) is different from the actual position, then the Error Code P045E will be stored, and Check Engine light will be activated. Most vehicles will require multiple ignition cycles (with failure) before Check Engine light lights up.
Depending on the conditions that lead to this error code, symptoms can also lead to drivability issues, which is also the reason why this code must be addressed as soon as possible. Common symptoms include:
- Increase fuel consumption
- Rough engine idle
- Excessively lean exhaust
Common causes for this code include:
- Defective EGR valve
- Clogged EGR valve plunger (due to carbon or debris buildup)
- Defective EGR control solenoid/valve
- Open or shorted wiring or connectors in EGR B control circuit
- Defective DPFE sensor
- Bad EGR valve position sensor
- Defective or programming error in PCM
How to Check
As with other error codes, diagnosing this code starts with the use of a diagnostic scanner, digital volt/ohmmeter, and a dependable vehicle information source.
The technicians usually proceed by checking the whole EGR system related to the connectors and wiring. Burned or corroded components must be repaired or replaced.
Then, technicians continue their diagnosis by connecting the scanner to the diagnostic port and retrieving the stored codes, as well as the freeze frame data. They write this information down as it can determine whether to the problem is intermittent or not. Then, they will clear the code and then take the vehicle for a test drive to see if the code is reset.
If the code is reset, technicians will then connect the scanner and observe the data stream. They will check the desired EGR position (typically measured in percentage) and the actual EGR position as shown on the data stream. Within a matter of milliseconds, they must be identical. If the actual position of the EGR shows that it’s opened too far, then there must be a piece of carbon clogging the plunger opening or the EGR valve is defective.
The easiest way to check the EGR plunger is to remove the valve and check it. Unfortunately though, on some vehicle makes and models, the EGR valves are pretty hard to remove and reinstall. If the EGR is easy to remove for inspection, then this must be the first step, especially for vehicles with more than 100K miles. Carbon fouling and passage clogging are the most common cause of this problem, which usually happens in vehicles with high mileage. If the plunger seems to be weakened, the technician will remove the obstruction and then retest EGR system.
If there is no obstruction, the technician will proceed on following the recommendations from the manufacturer and test the EGR actuator solenoids using DVOM. Step down EGR valves may use multiple solenoids to affect the full spectrum of EGR system operation.
If the EGR valve for the vehicle uses EGR valve position sensor, then it must be integrated into the valve itself. The technician will then follow the recommendations set by the manufacturer, as well as the connector pinout chards and vehicle wiring diagrams found in the vehicle information source, to test individual components. If this is the case, defective parts must be replaced, and the system must be retested.
How to Fix
Common repairs include;
- Repair or replacement of burned or corroded connector or wiring in the EGR system
- Replacement of defective parts of the EGR valve position sensor
The DVOM can be sued to test the individual circuits between the PCM connector and the EGR valve connector. Before testing, all controllers that are related must be disconnected from the circuit.
Carbon deposit from the high level of detergent found in modern fuels is the leading cause of this code.
After doing all the diagnosis and repairs, the PCM must enter readiness mode before assuming the repair is successful.