P2C3D code meaning
Cylinder Head Temperature Sensor A/B Correlation
Powertrain system Generic code P2Cxx codes Check engine light
What P2C3D means
An engine with two head temperature sensors can check one against the other: after a long soak both should read close to each other and to coolant temperature, and while running their gap should stay inside an expected band. P2C3D means sensors A and B disagree beyond that limit although neither circuit shows a fault. No manufacturer publicly documents the code or its thresholds. From 2019, phased in until 2021, CARB asks makers that use extra component temperature sensors, also where those sensors sit in different coolant circuits, to have a monitoring plan approved. Ford's 2.7 L EcoBoost bulletins show that both PCM software and a revised CHT sensor can be to blame for implausible head readings. Compare both values on a cold engine; the one far from coolant temperature is suspect.
P2C3D at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P2C3D
- Check engine light without driveability complaints
- Clearly different values for head temperature A and B after a cold start
Common causes of P2C3D
- Most likelyOne of the two sensors has drifted out of tolerance
- PossibleContact resistance in one sensor circuit shifting its reading
- Less likelyEngine control software judging the pair too tightly
- Less likelyReal temperature difference from air pocket or poor flow in one head area
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cylinder head temperature sensor aCylinder head temperature sensor bECM
What each part of P2C3D means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| C | Area: hybrid propulsion. |
| 3D | The exact fault in that area. |
What to do next
- Note P2C3D and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2C3D
What does P2C3D mean?
P2C3D means "Cylinder Head Temperature Sensor A/B Correlation". An engine with two head temperature sensors can check one against the other: after a long soak both should read close to each other and to coolant temperature, and while running their gap should stay inside an expected band. It is a generic code, so it means the same on every make.
Is it safe to drive with P2C3D?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2C3D fail an emissions test?
Yes, it can. P2C3D is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2C3D to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P2C3D clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.