Chassis, generic

C0092 4WD/AWD Power Transfer Unit Position Sensor B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Covers position sensor B of the power transfer unit actuator, the redundant or second-channel position feedback the controller cross-checks against sensor A (C0091). Dual position sensors let the controller detect a single faulty channel and keep metering the AWD coupling safely. This code is set when sensor B is out of range, open, shorted or does not track sensor A within tolerance. AWD coupling patents describe closed-loop control of the clutch actuator using position feedback, where losing a channel degrades control. A fault makes the position feedback untrustworthy, so the controller may default to a safe torque split or two-wheel drive and set the AWD/4WD warning lamp; braking and ABS are unaffected. The entry follows the SAE J2012 generic definition and dual-channel actuator position sensing.

Likely causes

Position sensor B failed or out of range
Sensor A/B signals do not correlate
Harness or connector fault

Symptoms

  • AWD/4WD warning lamp on
  • Default torque split or 2WD mode
  • Inconsistent AWD engagement

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€200–1,600
Time1–4 h

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

Parts involved

ptu pos sensor b

Related codes

C0091C0090C0093

References: patents.google.com, en.wikipedia.org.