P0235Powertrain
Powertrain · SAE
Turbocharger/Supercharger Boost Sensor A Circuit
Meaning
The turbocharger A boost pressure sensor (MAP/boost) outputs a signal outside the allowed operating range. The ECM cannot determine intake manifold pressure.
Common causes
- Short to ground or to supply voltage in the sensor wiring
- Open circuit in the 5 V reference supply or sensor ground
- Faulty or failed MAP/boost sensor
- Disconnected, corroded, or damaged connector
- Leak in the hose between sensor and boost duct
Symptoms
- Check-engine light on
- Engine power limited (limp-home mode)
- Black smoke or excessive exhaust
- Sluggish acceleration and reduced turbo response
- Increased fuel consumption
Severity
High: without a reliable boost pressure signal the ECM cannot optimise supercharging; undetected overboost risks engine damage.
What to do
- Check 5 V reference supply voltage and ground continuity at the sensor connector
- Measure signal voltage and compare against expected values at rest and under load
- Inspect wiring for shorts or opens
- Check boost hose integrity between manifold and sensor
- Replace the MAP/boost sensor if the electrical circuit is intact