P0237Turbocharger/Supercharger Boost Sensor A Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Boost sensor A measures the absolute pressure between charge air cooler and throttle – GM calls it TIAP, Ford TIP – usually combined with an intake air temperature sensor; its voltage rises with pressure. With the ignition on and the engine stopped it must read the same as manifold and barometric pressure. P0237 means the signal voltage is below its lower limit: GM below 14.4 % of 5 V (about 50 kPa) for roughly 4 s with the warning light in the first trip, Ford below 0.19 V for 5 s, Saab's V6 below 0.30 V for 1 s. Causes are a signal wire shorted to ground, an open 5 V reference or a failed sensor. Saab's 1.6 turbo only lights a service lamp for this code. With a sensor fault boost control is switched off and only the base boost of the wastegate spring remains, with a clear loss of power.
- What you may notice
- Check engine light on
- Clear loss of power, only base boost
- Boost reading implausible in a scan tool
- Likely causes
- LikelySignal or 5 V reference wire open or shorted to ground
- LikelyConnector unplugged or corroded
- PossibleSensor faulty internally
- Rare5 V reference pulled down by another sensor
- RareEngine module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €30 – €200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.