Loose, corroded or damaged connector at the EGR temperature sensor B; Chafed, broken or heat-damaged wiring to the sensor, causing intermittent open or short circuits; Failing EGR temperature sensor B giving an unstable signal; Poor sensor reference supply or ground shared with other sensors; Heavy carbon build-up or a faulty EGR valve or cooler causing unstable temperature readings; Internal engine control unit fault or outdated software, where a known issue is documented for the model.

P041E

EGR Temperature Sensor B Circuit Intermittent/Erratic.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
4: AreaAuxiliary emission controls
1E: FaultThe specific fault in that area

What it means

P041E means the engine control unit has seen the signal from EGR temperature sensor 'B' drop out, jump or behave erratically when it should change smoothly with exhaust gas temperature. The control unit uses this sensor to check that exhaust gas recirculation is flowing and cooling as expected. Which sensor is 'B' (and where it sits, for example before or after the EGR cooler) depends on the engine, so check the model-specific data.

Symptoms

Engine warning light on
Possible reduced power or limp mode on some models
Rough running or hesitation if EGR operation is affected
Other EGR or emissions-related codes stored alongside it
Failed or pending emissions test readiness

Possible causes

Loose, corroded or damaged connector at the EGR temperature sensor Blikely
Chafed, broken or heat-damaged wiring to the sensor, causing intermittent open or short circuitslikely
Failing EGR temperature sensor B giving an unstable signallikely
Poor sensor reference supply or ground shared with other sensorspossible
Heavy carbon build-up or a faulty EGR valve or cooler causing unstable temperature readingspossible
Internal engine control unit fault or outdated software, where a known issue is documented for the modelrare

How to diagnose

Read all stored and pending codes and note the freeze frame data (engine temperature, load, speed) to see when the fault occurred.
Check for related EGR, exhaust temperature or sensor supply codes, as these point towards a shared wiring or supply problem.
Inspect the sensor connector and wiring along its whole length for corrosion, looseness, heat damage and rubbing, and wiggle-test them with live data on screen.
Watch the EGR temperature sensor B live data when cold, warm and with the EGR commanded; look for spikes or dropouts and compare with sensor A if fitted.
Check the sensor supply voltage and ground at the connector against the manufacturer's specification for the model.
Test the sensor resistance or signal against the manufacturer's temperature chart, if one is available for the engine.
Inspect the EGR valve, cooler and pipework for carbon build-up, leaks or damage, following the model-specific procedure.
Check for manufacturer software updates or technical bulletins relating to this code on the vehicle.

How to fix

Clean, secure or replace the corroded or loose connector terminals.
Repair or replace damaged wiring between the sensor and the control unit.
Replace the EGR temperature sensor B if its readings are erratic or out of specification.
Repair the sensor supply or ground fault if it is found.
Clean or replace the EGR valve or cooler if a fault there is confirmed as the cause.
Update the control unit software only if an outdated or faulty calibration is a documented cause for this vehicle.

Can I keep driving?

Low severity

The car can usually be driven for a short time, so book it in soon. If it goes into limp mode, runs roughly or shows additional warnings, have it checked promptly.

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