P012C code meaning
Turbocharger/Supercharger Inlet Pressure Sensor A Circuit Low
Powertrain system Generic code P01xx codes Check engine light
What P012C means
The turbocharger/supercharger inlet pressure sensor A sits between the air filter and the compressor. The engine uses it for the compressor pressure ratio, to judge air filter restriction (ambient minus inlet pressure) and to cross-check the other pressure sensors. P012C means the signal voltage is below its lower limit – typically a signal wire shorted to ground, an open signal or 5 V reference wire, or a failed sensor. GM's supercharged V8 sets it below 3 % of the 5 V reference (about 0.15 V), with 320 of 400 samples failing, continuously monitored; two trips are normal, one in some 2019 applications. FCA documented false settings on the 2019 Jeep Wrangler 2.0 turbo that were cured by a software update. A substitute value is used and power may be limited.
P012C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 1 hours
- Clears after repairAfter a drive cycle
Symptoms of P012C
- Check engine light on
- Often no noticeable symptoms
- Power limitation possible
Common causes of P012C
- Most likelyConnector unplugged or corroded, signal or reference wire open
- PossibleSignal wire shorted to ground
- PossibleSensor failed internally
- Less likelyControl module software (false setting)
- Less likely5 V reference shorted by another sensor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Turbocharger inlet pressure sensor aSensor wiringSensor reference voltage
What each part of P012C 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. |
| 2C | The exact fault in that area. |
What to do next
- Note P012C 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 P012C
What does P012C mean?
P012C means "Turbocharger/Supercharger Inlet Pressure Sensor A Circuit Low". The turbocharger/supercharger inlet pressure sensor A sits between the air filter and the compressor. It is a generic code, so it means the same on every make.
Is it safe to drive with P012C?
Drive gently and only to a workshop. With P012C the car can go into limp mode (reduced power) to protect itself.
Will P012C fail an emissions test?
Yes, it can. P012C 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 P012C to fix?
Difficulty: easy. A typical repair takes 0.3 to 1 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P012C 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.