P012C
Turbocharger/Supercharger Inlet Pressure Sensor A Circuit Low
Forced induction (turbo/supercharger)
Generic OBD-II
High
What it means
P012C means the turbocharger/supercharger inlet pressure sensor 'A' is sending a signal that's too low — usually a short to ground, an open, or a failed sensor. Because the ECM uses this reading to manage boost, it will often limit power or enter limp mode until the sensor circuit is repaired.
High
Can I keep driving? Drivable but expect reduced power — the ECM often limits boost or enters limp mode when this pressure signal is out of range.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power or limp/failsafe mode
- Sluggish acceleration or lack of boost
- Turbo inlet pressure reads at or near zero on a scan tool
Common causes
Most likely first
- Faulty turbocharger/supercharger inlet pressure sensor 'A'Likely
- Signal circuit shorted to ground or openCommon
- Loose or corroded connector at the sensorCommon
- Poor sensor ground or reference voltageLess often
- Faulty ECM (rare — confirm sensor and wiring first)Less often
How to diagnose & fix
Work through it in order
- Read the live inlet-pressure value — a circuit-low fault typically shows an implausibly low or zero reading.
- Inspect the sensor connector and harness for a short to ground, open, or corrosion.
- Check the sensor's 5V reference and ground with the key on.
- Back-probe the signal wire to decide whether the sensor or the wiring is at fault.
- Replace the inlet pressure sensor if it reads low with good wiring, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P012C?+
Short-term, yes, but the engine may limit boost or run in limp mode, so power will be down. Get the sensor circuit fixed before extended driving.
Can I just clear P012C?+
It returns as soon as the ECM sees the low signal again. Repair the sensor or wiring before clearing.
Related codes
Often seen with P012C
Read & clear P012C 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