P2E56
Moderate Severity (Level 3)Exhaust Pressure Sensor C Circuit Low
P2E56 usually means exhaust Pressure Sensor C Circuit Low.
Can you still drive with P2E56?
⚠️Short-distance driving is usually OK, but have this diagnosed within a week to prevent further damage.
Typical repair cost: $80 – $1200
Severity Level 3 — Moderate
This code indicates a moderate issue that may affect vehicle performance and fuel economy. Continued driving is possible in most cases, but prompt diagnosis and repair are recommended to prevent further damage.
Common Symptoms
- Engine performance reading zero or abnormally low
- Check Engine Light illuminated
- Diagnostic trouble code (DTC) stored in module memory
- Fault may be intermittent — code may clear itself and reappear
- Reduced vehicle functionality related to the powertrain/engine system
Possible Causes
- Failed engine sensor or actuator — internal resistance has increased, outputting a signal lower than specification
- Damaged wiring or corroded connector in the powertrain/engine system circuit introducing high resistance
- Short to ground in the powertrain/engine system signal wire — wire chafed through, signal voltage pulled low
- Loose or oxidized ground connection for the engine sensor or actuator — clean the ground and retest before replacing parts
- Low system voltage (weak battery or failing alternator) causing sensor reference voltage to sag
Common Fixes
- Scan vehicle with a professional-grade OBD2 scanner to read all stored codes and freeze frame data — note the conditions when the code set ($20-129 at shop, free at auto parts store for basic scan)
- Visually inspect the powertrain/engine system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $52 diagnostic fee at shop)
- Test engine sensor or actuator with a multimeter at the connector — compare readings to factory service manual specs. If out of spec, replace engine sensor or actuator ($80-1200)
- Check the reference voltage supply to engine sensor or actuator — should be steady 5V (or 12V) — if low, trace back to PCM/BCM voltage regulator ($121-649 if module repair needed)
- Perform a voltage drop test on the ground side of the powertrain/engine system circuit — more than 0.1V drop means a bad ground that must be cleaned/repaired ($96-157 at shop)
Estimated Repair Cost
These are estimated costs based on generic repair data. Actual costs may vary depending on your vehicle, location, and labor rates.
Frequently Asked Questions
What does P2E56 mean?
P2E56 stands for "Exhaust Pressure Sensor C Circuit Low". P2E56 usually means exhaust Pressure Sensor C Circuit Low.
Can you drive with P2E56?
Short-distance driving is usually OK, but have this diagnosed within a week to prevent further damage.
How much does it cost to fix P2E56?
Repair costs for P2E56 typically range from $80 to $1200, depending on your vehicle make, model, and local labor rates. Common fixes include: Scan vehicle with a professional-grade OBD2 scanner to read all stored codes and freeze frame data — note the conditions when the code set ($20-129 at shop, free at auto parts store for basic scan); Visually inspect the powertrain/engine system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $52 diagnostic fee at shop); Test engine sensor or actuator with a multimeter at the connector — compare readings to factory service manual specs. If out of spec, replace engine sensor or actuator ($80-1200).
Will P2E56 clear itself?
Related Repair Costs
Explore Repair Costs
Related OBD-II Codes
These codes are in the same range as P2E56 and often share similar causes and fixes.
Worried about repair costs?
Get transparent estimates and verify your mechanic's quote before authorizing repairs.
Related Discussions
See what other car owners are saying about this code and related repairs.
View P2E56 discussions in the community