What it means
EGR temperature sensor B signal jumps or drops out intermittently. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
EGR temperature sensor B monitors exhaust temperature at its location in the EGR passage. The control module checks the signal for stability and sets P041E when it jumps or drops out intermittently, often as vibration disturbs a connector or a harness routed near a moving or vibrating part.
Common causes
Most likely first.
- Intermittent connector
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check engine light on
- Possible EGR-related drivability issues
How to diagnose it
- Read freeze-frame data and review live sensor B readings to see whether the signal dropped out during vibration, engine movement, or a change in EGR operation.
- Inspect sensor B's connector for loose fit, corrosion, damaged pins, or a seal that could allow moisture in.
- Trace the sensor B harness and check for rubbing, heat damage, or contact with vibrating components.
- With live data displayed, gently move the connector and harness to see whether the reading becomes erratic.
- Check sensor B and circuit continuity against the manufacturer's specification, including the connector terminals that may lose contact intermittently.
Common fixes
- Secure the sensor B connector and harness so vibration cannot pull or rub them.
- Clean or repair loose or corroded connector terminals.
- Replace damaged wiring or connector seals that allow intermittent contact.
- Replace sensor B if its signal remains erratic with a sound, stable circuit.
Can I keep driving?
Short trips may be possible if the engine runs smoothly, but address the intermittent fault soon because it can become a persistent EGR control problem. Stop driving if severe roughness or stalling develops.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.