P012D code meaning
Turbocharger/Supercharger Inlet Pressure Sensor A Circuit High
Powertrain system Generic code P01xx codes Check engine light
What P012D means
The turbocharger/supercharger inlet pressure sensor A sits ahead of the compressor – between air filter and turbocharger, or on GM's supercharged V8 between throttle and supercharger. It is an analogue 5 V pressure sensor used for the compressor pressure ratio, filter restriction and cross-checks with the other pressure sensors. P012D means the signal voltage is above its upper limit – typically the signal wire shorted to the 5 V reference or battery voltage, or an open sensor ground that lets the signal rise to the reference. GM's supercharged LT4/LT5 sets it above 97 % of the reference (about 124 kPa) with 320 of 400 samples failing, monitored continuously; two trips on the LT4, one on the 2019 LT5. FCA documented false settings on the 2019 Jeep Wrangler 2.0 turbo, fixed by new engine software. The control module substitutes a modelled or ambient value and may limit boost.
P012D at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P012D
- Check engine light on
- Reduced power or limp mode possible
- Often no noticeable symptoms
Common causes of P012D
- Most likelySignal wire shorted to 5 V reference or battery voltage
- PossibleSensor ground open or connector corroded
- PossibleSensor faulty internally
- Less likelyControl module software (false setting)
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 P012D 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. |
| 2D | The exact fault in that area. |
What to do next
- Note P012D 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 P012D
What does P012D mean?
P012D means "Turbocharger/Supercharger Inlet Pressure Sensor A Circuit High". The turbocharger/supercharger inlet pressure sensor A sits ahead of the compressor – between air filter and turbocharger, or on GM's supercharged V8 between throttle and supercharger. It is a generic code, so it means the same on every make.
Is it safe to drive with P012D?
Drive gently and only to a workshop. With P012D the car can go into limp mode (reduced power) to protect itself.
Will P012D fail an emissions test?
Yes, it can. P012D 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 P012D to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P012D 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.