U0598: Invalid Data Received From AC/DC Converter Control Module B
What to do
Have this looked at by someone qualified on hybrid and electric systems — this is the high-voltage side of the car, and the orange cabling is not something to investigate at home.
The symptom that tells you most is the twelve-volt battery. On a hybrid or EV there is no alternator: a converter steps the big battery down to run the lights, the computers and everything ordinary. So a small battery that keeps going flat on an electric car is usually a converter fault, not a battery fault — and replacing the battery does not fix it.
Expect the car to protect itself: reduced power, no electric-only running, or a refusal to charge. That is the system declining to act on numbers it cannot trust.
If the car has been through deep water, or had any high-voltage component replaced recently, say so. Both are common triggers, and the second is often a software mismatch rather than a failed part.
What this code means
AC/DC converter control module B is broadcasting data that cannot be accepted as true. It is the second on-board charging path, used where a vehicle charges at higher power or from two supplies. See U0400 for what an invalid-data code is and why the module it names is usually the messenger rather than the culprit.
Converters are how an electrified vehicle moves energy between voltages and forms, and each type does a different job — the names are not interchangeable.
- DC/DC steps the traction battery's hundreds of volts down to the twelve-volt system. It replaces the alternator entirely, which is why a hybrid or EV with a flat twelve-volt battery is a DC/DC problem rather than a charging one.
- AC/DC rectifies incoming alternating current when charging from a mains supply — the on-board charger.
- DC/AC inverts battery direct current into the alternating current a traction motor needs, and back again under regeneration.
- AC/AC conditions alternating current between forms, in the specific architectures that need it.
A second unit — the B in these titles — means either a redundant converter or a second circuit serving a separate load, and on a vehicle with two, a fault on one is genuinely useful: everything the two share is proven good.
What makes converter data worth trusting carefully is that everything downstream believes it. A converter reporting an output voltage it is not producing lets the rest of the car make decisions on a number that is not true, which is why the network rejects implausible values rather than working with them.
These modules sit in the high-voltage system. Orange cabling is not to be disturbed by anyone without high-voltage training, and the diagnosis here belongs with a qualified technician rather than a home multimeter.
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
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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