U0110: Lost Communication With Drive Motor Control Module A
Do not keep driving
Do not attempt to investigate this yourself, and do not let a workshop without hybrid or electric vehicle training attempt it either. The system this module controls runs at several hundred volts, which is lethal rather than merely unpleasant, and the orange cables are marked that colour for exactly this reason. Proper isolation before any work is not optional.
Expect the vehicle to lose electric drive. On a hybrid the engine may still run and get you a short distance; on an electric vehicle it will not move at all. Have it recovered to somewhere qualified rather than driven.
The reassuring part: the actual fault is usually in the ordinary low-voltage wiring, its connectors or a power supply — none of which requires touching the high-voltage side — so this is often far less serious than it sounds. It simply has to be established by someone equipped to do it safely.
What this code means
The drive motor control module has stopped being heard from. The general reasoning is at U0100.
This is a hybrid and electric vehicle module, and it controls the inverter that turns battery direct current into the alternating current that drives the motor. Losing communication with it removes electric propulsion entirely. On a full hybrid the engine may still run and the vehicle may limp; on a series hybrid or an electric vehicle there is no alternative and the car does not move.
The safety context is different from anything else in this family and must not be treated as ordinary electrical work. The circuits this module commands run at several hundred volts direct current, which is lethal in a way that nothing in a conventional vehicle is. The orange cabling is a warning, not decoration.
Do not investigate this yourself, and do not let an unqualified workshop investigate it either. High-voltage systems require specific training, insulated tools and a documented isolation procedure before anything is touched. That is not caution for its own sake — the energy available is enough to kill instantly, and it is present whether or not the vehicle appears to be switched on.
With that said, the ordinary causes still apply: the low-voltage supply to the module, its earth, its connectors and the data bus are what fail, and none of those requires touching the high-voltage side to check.
Likely causes
Start here
- Damaged data bus wiring · specialist
- Corroded or loose connector · specialist
- Failed power or earth supply to the module · specialist
Less common
- Another module holding the bus down · specialist
- Faulty power inverter · specialist
- Low system voltage · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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