EGR B valve stuck open or not seating because of carbon build-up; Faulty EGR B valve actuator or internal position sensor; Wiring or connector fault in the EGR B control or feedback circuit, such as a short, chafing, corrosion or poor terminal tension; Sticking or worn valve mechanism, for example a seized or broken valve spindle or linkage; Vacuum control fault on vacuum-operated systems, such as a leaking line, a faulty solenoid or a faulty vacuum source; Control unit driver fault or outdated software calibration, where one is known to apply to the model.

P045E

EGR B Control Stuck Open.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
4: AreaAuxiliary emission controls
5E: FaultThe specific fault in that area

What it means

P045E is the generic code for the EGR B control being stuck open. The engine control unit has seen that the second exhaust gas recirculation valve or circuit is passing flow when it has been commanded closed, or that its position feedback does not match the commanded closed position. Which valve counts as 'B' and how the fault is detected depends on the make, model and engine.

Symptoms

Engine management light on
Rough or unstable idle
Stalling or near-stalling when coming to rest
Hesitation or poor response at low throttle
Hard starting or rough running just after start-up
Possible increase in smoke or fuel consumption on some engines

Possible causes

EGR B valve stuck open or not seating because of carbon build-uplikely
Faulty EGR B valve actuator or internal position sensorlikely
Wiring or connector fault in the EGR B control or feedback circuit, such as a short, chafing, corrosion or poor terminal tensionpossible
Sticking or worn valve mechanism, for example a seized or broken valve spindle or linkagepossible
Vacuum control fault on vacuum-operated systems, such as a leaking line, a faulty solenoid or a faulty vacuum sourcepossible
Control unit driver fault or outdated software calibration, where one is known to apply to the modelrare

How to diagnose

Read all stored and pending codes and freeze frame data to see load, speed and temperature when the fault set, and note any related EGR, air flow or boost codes.
Check for technical service bulletins or known EGR issues for the specific model and engine.
Visually inspect the EGR B valve, its wiring, connector and any vacuum lines for damage, heat or oil contamination, corrosion and loose fittings.
With a scan tool, compare commanded and actual EGR B position at idle and while commanding the valve closed, and check that the reading follows the command.
Check the supply, earth and signal circuits at the valve connector against the manufacturer's data, including voltage drop under load.
On vacuum-operated systems, test the vacuum supply, control solenoid and valve diaphragm for leaks and correct operation.
Remove the valve and inspect it for carbon build-up, a stuck valve or a broken spindle, and check the passages for blockage, following the procedure for the model.
After repair, clear the codes and road test while monitoring EGR position and confirming the fault does not return.

How to fix

Clean carbon deposits from the valve and passages if the valve is serviceable and then seats fully closed; replace the valve if it cannot be restored.
Replace the EGR B valve or actuator if its motor, position sensor or valve mechanism is faulty.
Repair or replace damaged wiring, connectors and terminals in the EGR B circuit.
Replace leaking vacuum lines or a faulty control solenoid on vacuum-operated systems.
Update the control unit software only where the manufacturer lists an outdated calibration as a known cause for this fault.

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but have it checked soon. A valve stuck open can cause stalling and poor running, and carbon build-up may worsen and affect emissions and engine wear.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.