U0293: Lost Communication With Hybrid/EV Powertrain Control Module
Do not keep driving
The vehicle will most likely refuse to move, and that is deliberate. This module is the one that decides how the engine and the electric motors work together. Without it, nothing is coordinating them — and a hybrid running with nothing in charge would be genuinely unsafe, so the car shuts the powertrain down instead. It is protecting itself and you, not broken beyond use.
Have it recovered rather than trying to persuade it to move.
The single most useful thing to ask for first is a 12-volt battery test. Hybrids and electric cars still have an ordinary 12-volt battery to run their computers, and a weak one makes modules all over the vehicle stop talking at once — which produces exactly this code along with a frightening list of others. It is common, it is cheap, and it is regularly missed while much more expensive things are investigated.
Do not let an expensive module be replaced before the basics are ruled out — its power supply, its earth, the network wiring, and whether other modules are silent too. And do not investigate anything orange yourself; those voltages are lethal.
What this code means
The hybrid or electric powertrain control module has stopped being heard from. See U0200 for the block's framing and U0100, whose reasoning about what a lost communication code means applies to every code in this family.
This is the supervisory module of a hybrid or electric powertrain, and losing it is closer to U0100 in seriousness than to anything else in the U02xx block.
Its job is arbitration. On a hybrid, something has to decide moment by moment how much torque comes from the engine and how much from the motors, when to charge the pack and when to draw from it, when to start and stop the engine, and how much regeneration to apply for a given brake pedal position. No individual module can make those calls — they are decisions about the whole system, and this is the module that makes them.
With it silent, nothing arbitrates. The individual components are all present and none of them knows what it should be doing. The universal response is to shut the powertrain down into its safest available state, which on most vehicles means it will not move, and this code is marked accordingly.
That is protection rather than damage, and the distinction is worth making to an owner facing a vehicle that will not go. A hybrid powertrain with unarbitrated components would be genuinely dangerous — torque arriving from two sources with nothing coordinating them — so refusing to move is the correct behaviour.
The diagnosis is U0100's diagnosis and it should be insisted on. The module's power and earth, the network wiring, whether other modules are also silent, and whether one failed module is holding the bus down — all of those come before the module itself, which on a hybrid is among the most expensive parts on the vehicle and normally requires programming to the car before it will function.
One consideration is specific to hybrids and electric vehicles and is genuinely common: the 12-volt battery. These vehicles depend on a healthy 12-volt supply to wake and run their control modules, and a weak 12-volt battery produces a cascade of lost-communication codes across the whole vehicle that looks catastrophic and is not. Testing it is the first thing, not the last — see U0298, where the reason it goes flat is set out.
And the high-voltage caution stands: orange cabling, lethal voltages, and nothing to be investigated at home.
Likely causes
Start here
- Failed power or earth supply to the module · moderate
- Damaged data bus wiring · moderate
- Another module holding the bus down · specialist
- Corroded or loose connector · easy
- Blown fuse or failed supply · easy
Less common
- Fault stored in the hybrid powertrain control module · specialist
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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