Faulty exhaust pressure sensor C; Damaged or corroded wiring or connector at the sensor; Clogged or restricted exhaust pressure sensor tube or port; Exhaust leaks upstream of the sensor; PCM software issue or internal fault; Aftermarket or incorrect sensor installed; Extreme carbon buildup in the exhaust system affecting pressure readings

DTC codes / P2Exx · Hybrid propulsion / P2E55

P2E55Exhaust Pressure Sensor C Circuit Range/Performance

Q: What does code P2E55 mean?

Exhaust Pressure Sensor C Circuit Range/Performance. P2E55 means the powertrain control module (PCM) has detected that the exhaust pressure sensor C circuit is reporting a signal outside the expected range or behaving erratically during key-on or running tests. The PCM compares the sensor's voltage to a calculated model and flags a performance fault when the signal does not track exhaust pressure as expected.

P2E55 means the powertrain control module (PCM) has detected that the exhaust pressure sensor C circuit is reporting a signal outside the expected range or behaving erratically during key-on or running tests. The PCM compares the sensor's voltage to a calculated model and flags a performance fault when the signal does not track exhaust pressure as expected.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode in some vehicles
Poor fuel economy or rough running under load
Intermittent hesitation or stumble during acceleration
Failed emissions test due to incomplete monitors
Possible black smoke or excessive exhaust odor in severe cases

Common causes, most likely first

Faulty exhaust pressure sensor C
Damaged or corroded wiring or connector at the sensor
Clogged or restricted exhaust pressure sensor tube or port
Exhaust leaks upstream of the sensor
PCM software issue or internal fault
Aftermarket or incorrect sensor installed
Extreme carbon buildup in the exhaust system affecting pressure readings

How to diagnose and fix it

Connect a scan tool and record freeze-frame data and live sensor voltage to confirm the fault
Visually inspect the sensor, connector, and wiring for damage, corrosion, or loose pins
Check the sensor tube or port for blockage and clean it if restricted
Perform a key-on engine-off voltage check at the sensor connector and compare to specification
Test the sensor with a known pressure source or compare its reading to a mechanical gauge
Inspect for exhaust leaks upstream of the sensor using a smoke machine or visual check
If all checks pass, reprogram the PCM or replace the sensor as needed

What the exhaust pressure sensor C code hides

A clogged sensor tube is a frequent cause that mimics a failed sensor, so always check the tube before replacing parts.
Exhaust leaks upstream of the sensor can cause erratic readings that set this code without any sensor fault.
Some vehicles require a PCM relearn or software update after sensor replacement to prevent repeat codes.
The code can be set by a momentary glitch during key-on, so clearing it and test-driving may confirm if it is a hard fault.
Aftermarket sensors often have different voltage curves and can trigger this code even when new.

Can I keep driving with P2E55?

You can usually drive with this code, but avoid heavy acceleration or towing until it is diagnosed, as the PCM may be using inaccurate pressure data for fuel and emissions control. If the engine enters limp mode or runs poorly, seek service promptly.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.