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U01BE Lost Communication With Drive Motor A Clutch Actuator

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Some electrified drivetrains can uncouple a drive motor from its wheels so that an idle motor is not spun by the road. The Chevrolet Corvette E-Ray has such a disconnect: GM bulletin 24-NA-273 (January 2025, 2024–2025 models with LT2 engine) ties U01BE with a lit MIL to an internal microchip fault in the M162 drive motor disconnect clutch actuator, and the remedy is a new actuator. A Rivian patent shows why the actuator matters: before engagement the motor speed is matched to the output speed, and the control system judges from the motor's reaction whether the clutch has engaged. With the actuator silent, the system can neither couple the motor nor confirm its state, so electric drive on that axle is lost. U04BF covers invalid data from the actuator.

Likely causes

Internal electronic fault in the clutch actuator (GM M162 replaced)
Connector or wiring fault at the actuator on the drive unit
Actuator without supply voltage or ground

Symptoms

  • MIL on
  • Electric drive on one axle or all-wheel drive unavailable
  • Reduced acceleration

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€300–2,000
Time1–4 h

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

Parts involved

drive motor a clutchcan bus

Related codes

U04BFU0110U0411

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