P0235 code meaning
Turbocharger/Supercharger Boost Sensor A Circuit
Powertrain system Generic code P02xx codes Check engine light
What P0235 means
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. P0235 is the general fault of sensor A's circuit or signal, for modules that do not split low, high and range. GM, Ford and Saab do not use it; Audi documents it on the Q7 TDI together with over- and underboost, so there it also marks an implausible boost value, for example from a charge air leak or jammed turbo vanes. No manufacturer threshold for this code was found. 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.
P0235 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyEasy, DIY possible
- Typical labor0.5 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0235
- Check engine light on
- Clear loss of power, only base boost
- Boost reading implausible in a scan tool
Common causes of P0235
- Most likelyConnector at the boost sensor corroded or loose, broken wire
- PossibleBoost sensor faulty, often oily from crankcase ventilation
- PossibleCharge air leak or jammed turbo vanes causing an implausible value
- Less likely5 V reference shorted by another sensor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Boost pressure sensor aSensor wiringCharge air hoses
What each part of P0235 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 2 | Area: fuel and air metering (injector circuit). |
| 35 | The exact fault in that area. |
What to do next
- Note P0235 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0235
What does P0235 mean?
P0235 means "Turbocharger/Supercharger Boost Sensor A Circuit". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0235?
Drive gently and only to a workshop. With P0235 the car can go into limp mode (reduced power) to protect itself.
Will P0235 fail an emissions test?
Yes, it can. P0235 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0235 to fix?
Difficulty: easy. A typical repair takes 0.5 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0235 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.