What it means
The ECM detects a range/performance fault on the exhaust pressure sensor c circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Exhaust pressure sensor C measures pressure at a particular point in the exhaust system for engine and emissions control. P2E55 means the control module sees a signal from sensor C that is present but outside the expected range or response pattern, so it may limit engine performance or emissions functions.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
Symptoms
- Check-engine light may be on
- Reduced engine performance
- Increased emissions or failed emissions test
How to diagnose it
- Review freeze-frame data and compare live sensor C pressure readings with other relevant pressure data at similar engine conditions.
- Inspect sensor C and its pressure connection for a loose mounting, blockage, leaks, or damage that could make its reading unrepresentative.
- Check the sensor C connector and harness for heat damage, corrosion, chafing, or loose terminals.
- Compare sensor C's response as engine conditions change with the manufacturer's specification.
- If the pressure connection and wiring are sound but the reading remains out of range, test sensor C and replace it if it fails.
Common fixes
- Secure sensor C and correct a displaced mounting.
- Clear a confirmed obstruction or repair a leak in sensor C's pressure connection.
- Repair damaged or corroded sensor C wiring or connector terminals.
- Replace sensor C if it has drifted outside the manufacturer's specification.
Can I keep driving?
Limit heavy-load driving if the engine has reduced power, and address the fault soon because inaccurate exhaust pressure data can affect emissions control. Stop if the engine loses power enough to make driving unsafe.
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.