P012B

Turbocharger/Supercharger Inlet Pressure Sensor A Circuit Range/Performance

Turbo / boost control Generic OBD-II High

What it means

P012B means the turbo or supercharger inlet pressure sensor "A" is reading a value that doesn't match expected conditions — it's out of range or implausible. Because the ECM uses this signal to manage boost, it may limit power or enter a reduced-power mode until the sensor, its wiring, or a boost leak is sorted out.

High

Can I keep driving? You can drive gently, but boost may be limited and the engine can drop into reduced-power mode; fix it before hard acceleration or towing.

Real-world scan data

Seen in

667

scans in the past year

Found in

0.1%

of scans

0.2%

of scans that found faults

Appears alongside · share of P012B scans

P2263in 90.0% of scans

P1525in 88.6% of scans

P0201in 88.5% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Reduced power or boost / limp mode
Hesitation or poor acceleration under load

Common causes

Most likely first

Faulty turbocharger/supercharger inlet pressure sensorLikely
Open, shorted, or corroded wiring or connector at the sensorCommon
Boost or vacuum leak giving the sensor an implausible readingCommon
Intercooler or intake restriction affecting inlet pressureLess often
Faulty ECM/PCM (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and compare the inlet-pressure reading to actual/barometric pressure on a scan tool.
Inspect the sensor connector and wiring for damage or corrosion.
Check the intake and boost plumbing for leaks or restriction.
Replace the sensor if it reads out of range with good wiring; repair leaks.
Clear and retest under load.

FAQ

Quick answers

Is it safe to drive with P012B?+

Light driving is usually fine, but the ECM may cap boost or cut power to stay safe. Avoid hard acceleration or towing until it's repaired.

Can I just clear P012B?+

It returns once the ECM sees the implausible pressure signal again. The sensor, its wiring, or a boost leak has to be addressed first.

Read & clear P012B yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX