What it means
The ECM detects a circuit high 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 specific point in the exhaust system. P2E57 means the control module sees sensor C's circuit signal above its expected range, often because the signal is shorted to battery voltage or the sensor circuit is open, and engine performance or emissions control may be affected.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- Connector pins corroded - high contact resistance
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 live readings for sensor C, comparing its high signal with other pressure data under similar conditions.
- Inspect sensor C's connector and harness for disconnection, heat damage, corrosion, or insulation rubbed through to a power wire.
- Check the sensor C signal wire for a short to battery voltage using the manufacturer's wiring information.
- Test the sensor C circuit for an open and check the sensor itself according to the manufacturer's procedure.
- Repair the identified fault and confirm sensor C reports plausibly and the code does not return.
Common fixes
- Reconnect or secure a loose sensor C connector.
- Repair a sensor C signal wire shorted to battery voltage or an open circuit.
- Clean or replace damaged sensor C connector terminals.
- Replace exhaust pressure sensor C if it is open or fails the manufacturer's test.
Can I keep driving?
If reduced power is present, avoid heavy loads and high-speed driving until sensor C's circuit is repaired. Continued operation with an unreliable exhaust pressure signal can affect emissions control; stop if the vehicle becomes unsafe to drive.
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.