Powertrain, generic (extended)

P2B6F Turbocharger/Supercharger A Temperature Sensor Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2B6F reports that the signal of turbocharger/supercharger temperature sensor A has fallen below its valid range. If the sensor is an NTC thermistor, whose resistance drops as it warms, a low voltage stands for a very high temperature, so the usual electrical causes are a signal wire shorted to ground or a sensor failed internally short. With an element whose resistance rises with heat (PTC) the relationship is reversed, and low means very cold. Because no manufacturer documents this code publicly, the sensor type depends on the application. Per CARB 13 CCR 1968.2 (e)(15), low and high out-of-range faults get separate codes. On a cold engine compare the displayed value with real conditions: a hot reading at rest points to a short. High reading: P2B70.

Likely causes

Signal wire shorted to ground, for example chafed near the exhaust
Sensor element shorted internally
Input circuit in the engine computer faulty

Symptoms

  • Warning lamp with stored code
  • Live data shows an extreme value even with the engine cold

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–400
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

turbocharger a temperature sensorwiring harnessecm

Related codes

P2B6EP2B70P2B71P2B90P2EC0

References: law.cornell.edu, en.wikipedia.org, patents.google.com.