U0594: Invalid Data Received From Hybrid/EV Powertrain Control Module
What to do
Have the twelve-volt battery tested first — before anybody starts on the hybrid system.
That sounds like odd advice for a hybrid fault, but it is the right one: a weak twelve-volt battery makes every module on an electrified car report nonsense at once, and it is the commonest cause of an alarming list of codes. It is also the cheapest thing to rule out.
Expect the car to protect itself — running on the engine only, refusing electric drive, reducing power, or declining to go into Ready. A car that will not start up is refusing to move on figures it cannot trust, which is the system working rather than failing.
Ask for all the stored codes to be read, not just this one. This module makes its decisions from what everything else tells it, so a code naming a battery, motor or converter is far more informative — and fixing that usually clears this.
What this code means
The hybrid/EV powertrain control module is broadcasting data that cannot be accepted as true. See U0400 for what an invalid-data code is and why the module it names is usually the messenger rather than the culprit.
This is the module that decides how an electrified vehicle drives — and because it coordinates rather than senses, an invalid-data code here has a particular meaning.
It arbitrates between the engine, the motors, the battery and the brakes: when the engine starts, how much torque comes from where, how hard regeneration pulls, whether the car may run on electricity alone. Every one of those decisions is made from data reported by other modules.
So this module publishing implausible values is very often downstream of something else. A battery module reporting an impossible state of charge, a motor controller reporting impossible torque, a converter reporting a voltage it is not producing — each makes this module's own output unreliable. Read the other stored codes first; on this code more than most, they are the diagnosis.
The vehicle's response is usually decisive rather than subtle. Hybrid systems fail safe by falling back: engine-only running where possible, no electric drive, reduced power, sometimes a refusal to enter Ready. A car that will not go into Ready is not being awkward — it is declining to move on numbers it cannot trust.
Twelve-volt supply is worth checking before anything expensive. A weak twelve-volt battery on a hybrid produces a cascade of implausible reports across every module, and it is the single most common cause of alarming multi-code presentations on these vehicles.
Likely causes
Start here
- Corroded or loose connector · specialist
- Damaged data bus wiring · moderate
Less common
- Water ingress into module · moderate
- Software updated on one module only · specialist
- Failed power or earth supply to the module · specialist
- Faulty battery energy 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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