P2B90 code meaning
Turbocharger/Supercharger B Temperature Sensor Circuit Low
Powertrain system Generic code P2Bxx codes Check engine light
What P2B90 means
P2B90 means the signal of temperature sensor B has dropped below the lowest value the engine computer accepts. What that says about temperature depends on the element: an NTC thermistor loses resistance when hot, so a low signal reads as extreme heat, whereas a platinum resistor of the kind Heraeus patented for turbo protection (US8328419B2) gains resistance with heat, so a low signal reads as extreme cold. Electrically both point the same way: a signal wire touching ground or a shorted element. No manufacturer publishes this code, so the sensor type of a given engine must be taken from its service data. CARB 13 CCR 1968.2 (e)(15) keeps low and high faults apart. The high counterpart is P2B91, the matching code for sensor A is P2B6F.
P2B90 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2B90
- Warning lamp with stored code
- Sensor B shows a fixed extreme value even on a cold engine
Common causes of P2B90
- Most likelySignal wire shorted to ground, for example melted insulation
- PossibleSensor element shorted internally
- Less likelyFaulty input stage in the engine computer
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Turbocharger b temperature sensorWiring harnessECM
What each part of P2B90 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 90 | The exact fault in that area. |
What to do next
- Note P2B90 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 P2B90
What does P2B90 mean?
P2B90 means "Turbocharger/Supercharger B Temperature Sensor Circuit Low". P2B90 means the signal of temperature sensor B has dropped below the lowest value the engine computer accepts. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B90?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2B90 fail an emissions test?
Yes, it can. P2B90 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 P2B90 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P2B90 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.