P012F code meaning
Engine Coolant Temperature / Engine Oil Temperature Correlation
Powertrain system Generic code P01xx codes Check engine light
What P012F means
P012F compares the coolant temperature sensor with the engine oil temperature sensor. The documented user is Ford's Power Stroke diesel. After a calibration update for the 6.0 litre engine, Ford uses it to monitor oil cooler efficiency: if the oil gets much hotter than the coolant at certain speed and load, the oil-to-coolant heat exchanger is probably clogged, and P012F sets together with the wrench lamp. On the 6.7 litre (2015–2018) several bulletins treat P012F as a false setting – partly below 5 °C ambient – cured by reprogramming the engine module. Ford's 2023 diesels run the cold-start comparison of coolant against oil temperature (35 °C limit after 6 h) under P0196 instead. GM does not use the code, and the code does not say which sensor or which system is at fault.
P012F at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 10 hours
- Clears after repairAfter a drive cycle
Symptoms of P012F
- Check engine light and/or wrench lamp (Ford)
- Raised oil temperature with a clogged oil cooler
- Often no driving symptoms when software is the cause
Common causes of P012F
- Most likelyOil cooler (oil-to-coolant heat exchanger) clogged – oil much hotter than coolant
- PossibleEngine module software (false setting, especially in cold weather)
- PossibleCoolant or oil temperature sensor inaccurate, or its wiring faulty
- Less likelyThermostat stuck open or low coolant
- Less likelyBlock heater in use (only coolant preheated)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Engine coolant temperature sensorEngine oil temperature sensorOil cooler
What each part of P012F means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| 2F | The exact fault in that area. |
What to do next
- Note P012F 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 P012F
What does P012F mean?
P012F means "Engine Coolant Temperature / Engine Oil Temperature Correlation". P012F compares the coolant temperature sensor with the engine oil temperature sensor. It is a generic code, so it means the same on every make.
Is it safe to drive with P012F?
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 P012F fail an emissions test?
Yes, it can. P012F 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 P012F to fix?
Difficulty: hard. A typical repair takes 0.5 to 10 hours of work. This is a job for a workshop.
Will P012F 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.