Chassis, generic

C00A5 Driveline Control Module Transfer Case Unit Control Circuit Driver

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

C00A5 concerns the output stage in the driveline module that powers the transfer case actuator, typically a DC gearmotor that shifts range and mode or presses a multi-plate clutch. Bosch describes such a transfer case clutch driven by a DC motor with worm gear through an H-bridge, with motor speed, worm wheel position and motor current measured; Magna's shift patent regulates the gearmotor speed by PWM and switches to closed-loop position control near the end of travel. The code is set when the module sees a fault at its own driver, such as overcurrent, a short to ground or battery, an open load or thermal shutdown, the categories listed for H-bridge ICs like TI's DRV8873-Q1. The actuator itself is covered by C00A6. No manufacturer publishes a C00A5 case. The transfer case then usually holds its last state or drops to 2WD.

Likely causes

Shorted transfer case motor wiring or connector
Binding or worn transfer case motor causing overcurrent
Defective H-bridge in the driveline module

Symptoms

  • 4WD/AWD cannot be engaged or range shift refused
  • 4WD service warning in the cluster

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,300
Time0.5–4 h

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

Parts involved

driveline moduletransfer case

Related codes

C00A1C00A6C00A7C00A8

References: patents.google.com, patents.google.com, ti.com.