P012A
Turbocharger/Supercharger Inlet Pressure Sensor A Circuit
Turbo / boost control
Generic OBD-II
High
What it means
P012A means the ECM sees a fault in the circuit for the turbocharger/supercharger inlet pressure sensor — the sensor that reports pressure entering the compressor. It's an electrical circuit fault, usually the sensor, its wiring, or the connector. Without a trustworthy signal the ECM often limits boost, so you may notice reduced power or limp mode.
High
Can I keep driving? Driveable but likely down on power — the engine may drop into limp mode to protect itself until the sensor circuit is fixed.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power or limp mode
- Hesitation or sluggish acceleration
- Erratic boost behavior
Common causes
Most likely first
- Faulty turbocharger/supercharger inlet pressure sensorLikely
- Open or shorted wiring in the sensor circuitCommon
- Loose or corroded connector at the sensorCommon
- Poor sensor ground or reference voltageLess often
- Faulty ECM/PCM (rare — rule out sensor and wiring first)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to capture the conditions when the code set.
- Inspect the sensor connector and wiring for damage, corrosion, or chafing.
- Check reference voltage and the sensor signal on a scan tool; with the key on and engine off it should read close to barometric pressure.
- Test the sensor against spec and replace it if the signal is out of range.
- Repair wiring as needed. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P012A?+
You can drive short distances, but the engine may limit boost and power. Get the sensor circuit checked before relying on full performance.
Can I just clear P012A?+
It returns when the ECM next sees the bad signal. The sensor or its wiring needs to be repaired first.
Related codes
Often seen with P012A
Read & clear P012A yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX