What it means
The ECM detects a circuit 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 so the control module can manage engine and emissions functions. P2E54 sets when the module detects an electrical fault in sensor C's circuit and cannot rely on its reading, which may trigger reduced engine performance.
Common causes
Most likely first.
- Sensor failed
- Wiring or connector fault
Symptoms
- Check-engine light may be on
- Reduced engine performance
- Increased emissions or failed emissions test
How to diagnose it
- Read freeze-frame data and stored codes, then compare live exhaust pressure sensor C data with other relevant pressure readings under the same conditions.
- Locate sensor C using the vehicle's service information and inspect its connector and harness for heat damage, chafing, corrosion, or a loose plug.
- Check the sensor C circuit connections and wiring continuity against the manufacturer's wiring diagram.
- Test the sensor C power, ground, and signal circuits using the manufacturer's procedure to isolate a circuit fault from a failed sensor.
- Repair the identified fault and confirm that sensor C data responds plausibly and the code does not return.
Common fixes
- Reconnect or secure the sensor C connector.
- Repair damaged or heat-affected wiring in the sensor C circuit.
- Clean or replace corroded sensor C terminals.
- Replace exhaust pressure sensor C if its circuit is intact but the sensor fails testing.
Can I keep driving?
If the engine has reduced power, avoid heavy loads and high-speed driving until the fault is diagnosed; stop if performance becomes unsafe. A faulty exhaust pressure signal can affect emissions control and may worsen engine or exhaust-system operation.
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.