P2B71 code meaning
Turbocharger/Supercharger A Temperature Sensor Circuit Range/Performance
Powertrain system Generic code P2Bxx codes Check engine light
What P2B71 means
P2B71 covers a reading from temperature sensor A on the turbocharger or supercharger that is electrically valid yet does not fit the operating state. Typical plausibility tests compare the value after a long engine-off soak with other temperature sensors, or check it against a model; Cummins patent US8082736B2 shows how a turbine-side temperature can be derived from pressure signals, which gives the computer such a reference. CARB 13 CCR 1968.2 (e)(15.2.1) asks for two-sided rationality checks on input sensors where feasible. No manufacturer documents this code publicly, so limits and timing are unknown. Usual culprits are a drifting element, poor contact or a sensor that sits loose in its bore. Open or shorted wiring sets P2B6E to P2B70 instead; sensor B has P2B92.
P2B71 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P2B71
- Warning lamp, often without noticeable driving change
- Turbo temperature in live data differs clearly from other temperatures after a cold start
- Boost may be trimmed back as a precaution
Common causes of P2B71
- Most likelySensor element aged by heat and reading off
- PossibleContact resistance at the connector distorting the signal
- Less likelySensor loose or not fully seated in its bore
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Turbocharger a temperature sensorWiring harnessECM
What each part of P2B71 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. |
| 71 | The exact fault in that area. |
What to do next
- Note P2B71 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 P2B71
What does P2B71 mean?
P2B71 means "Turbocharger/Supercharger A Temperature Sensor Circuit Range/Performance". P2B71 covers a reading from temperature sensor A on the turbocharger or supercharger that is electrically valid yet does not fit the operating state. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B71?
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 P2B71 fail an emissions test?
Yes, it can. P2B71 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 P2B71 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will P2B71 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.