P2E57

Code

Generic P — Powertrain

Exhaust Pressure Sensor C Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 23 EN: 34 RU: 23

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Page language: EN

Causes

Damaged or failed exhaust pressure sensor (sensor C)
Short circuit to battery voltage on the sensor signal wire
Incorrect or missing sensor reference voltage (5 V) from ECU
Corroded, loose or damaged connector or wiring (pins, insulation, chafing)
Poor ground or intermittent ground connection
Faulty ECU or module driver (less common)

Symptoms

Check Engine Light (MIL) illuminated and code P2E57 stored
DPF/exhaust regen faults, inability to perform regeneration or frequent regen attempts
Reduced engine performance or derate in some vehicles
Poor fuel economy or increased emissions
Possible stored freeze-frame data and related emissions codes

What to check

Read freeze frame and live data with a capable scan tool; note exhaust pressure sensor C values at key ON and during idle/boost
Visual inspection of sensor, connector and wiring for damage, corrosion, melted insulation, or pin push-out
Backprobe and measure sensor signal voltage with key ON (engine OFF) and compare to expected reference
Measure reference voltage (typically ~5.0 V) and ground at the sensor connector
Perform voltage drop/continuity checks between sensor connector and ECU connector for signal, reference and ground
Wiggle test wires while monitoring live data to find intermittent faults

Signal parameters

Sensor reference voltage: typically ~5.0 V (check factory data for exact value)
Normal sensor output: roughly 0.5–4.5 V proportional to exhaust/differential pressure (vehicle-specific)
High-circuit symptom: signal higher than maximum expected (often >4.8–5.0 V) or near battery voltage if shorted to 12 V
Low/no-signal: ~0 V if shorted to ground or open circuit; resistance to ground may be infinite for open circuit

Diagnostic algorithm

Retrieve freeze-frame and all related codes; record live sensor values (key ON engine OFF and during idle/run).
Visually inspect the sensor, connector, and harness for damage, contamination, or loose pins. Repair as needed.
With connector disconnected, measure reference voltage and ground at the sensor connector with key ON. Confirm reference ~5 V and good ground.
Backprobe the sensor signal wire with connector reconnected. Measure signal voltage with key ON (engine OFF). A voltage above the expected maximum suggests a short to battery or internal sensor fault.
Check continuity/resistance between sensor signal pin and the ECU signal input pin. Inspect for short to battery (signal to B+) and short to ground (signal to chassis) using an ohmmeter/power-off tests.
If wiring and connector are good, substitute a known-good sensor or temporarily replace sensor to verify fault clears.
If fault persists after sensor replacement, inspect/repair wiring harness or pins, and if necessary test/replace the ECU or module driver (verify with manufacturer procedures before ECU replacement).
Clear codes and perform a test drive/regeneration cycle to confirm repair. Re-scan for return of the code.

Likely causes

Open/shorted or chafed wiring between sensor and ECU (short to 12V)
Failing or internally shorted exhaust pressure sensor
Corroded/contaminated connector at the sensor
Bad sensor reference or ground due to harness damage or connector issue

Fault status

⚠️ Status

Fault sets MIL and stores code when exhaust pressure sensor C signal is higher than expected. Freeze-frame and live data captured by ECU. Condition may prevent or inhibit DPF regeneration or trigger derate strategies depending on vehicle.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-1.5 hours