P012A: Turbocharger/Supercharger Inlet Pressure Sensor A Circuit

What does P012A mean?

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. P012A is the general circuit fault. Ford's 2023 diesels use a digital SENT sensor here and set P012A when its error flag is raised or the value exceeds a limit for 5 s; lost communication is reported separately (U068B). FCA's 2019 Jeep Wrangler 2.0 turbo could set P012A, P012C and P012D falsely and was fixed with new engine software, so the software level is worth checking before replacing parts. GM's supercharged V8 uses only P012B–P012D. A substitute value, usually ambient pressure, is used.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Check engine light on
• Often no noticeable symptoms
• Power limitation possible

Common causes

• High Connector or wiring open, corroded or shorted
• Medium Sensor faulty (SENT sensor reports internal error)
• Medium Control module software (false setting)
• Low Engine control module faulty

Likelihood is a general estimate across vehicles; your make and model may differ.