Chassis, generic

C00A8 4WD/AWD Transfer Case Unit Actuator Position Sensor B

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C00A8 is the second position signal of the transfer case actuator. Whether B is a redundant copy of A or tracks a different part, the motor or the cam, is not published by any maker; BorgWarner, for example, puts a contact probe on the shift drum cam instead of the motor because a torsion spring sits in between, and reads five plateaus from 2WD high to 4WD low. Stellantis lists C00A8-13, circuit open, in TSB 08-237-23 and in 08-122-24, which replaced 08-239-23 for 2023 Wagoneer and Grand Wagoneer built 16 to 24 June 2023: the MIL must be on, and a loose shift motor connector is the cause, verified by pushing, pulling and pushing the plug again. Ford SSM 52152 names C00A8:11 and :13 on 2020–2023 Explorer/Aviator. Magna's Hall sensor patent shows a sensor that can be exchanged from outside.

Likely causes

Shift motor connector not latched (Stellantis 2023)
Harness damage at the heat shield near the transfer case (Ford)
Position sensor B defective

Symptoms

  • MIL illuminated (Stellantis), wrench indicator (Ford)
  • 4WD Service light, four-wheel drive not available

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–900
Time0.3–3 h

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

Parts involved

transfer case actuator pos b

Related codes

C00A7C00A6C00A5U0403

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, patents.google.com.