U0337 code meaning
Software Incompatibility With Battery Charger Control Module A
What U0337 means
Battery charger control module A is the charger built into a plug-in car: it turns mains AC into DC for the traction battery and coordinates with the charging station and the battery controller. U0337 appears when a partner module refuses the charger's software or calibration. No manufacturer documents U0337 publicly. Maserati updates the OBCM software on 2025 GranTurismo and Grecale electric models because a charging fault could only be cleared by unplugging and reconnecting (Rapid Update 751). FCA's bulletin 08-048-14 for the 2013–2014 Fiat 500e updated charger, vehicle control unit, inverter and battery controller together, partly to cut 12 V drain on incompatible charging stations. CARB expects plug-in hybrids to monitor charging performance. U019B is lost contact, U049C invalid data. Charging may stop.
U0337 at a glance
- Check engine lightUsually not
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0337
- Charging does not start or stops after a short time
- Charging fault message that clears only after replugging
- 12 V battery drained after charging sessions
Common causes of U0337
- Most likelyOn-board charger left on an older software level after other modules were updated
- PossibleCharger replaced without programming to the vehicle
- Less likelyCharger update interrupted, for example by low 12 V supply
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
On board charger
What each part of U0337 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 37 | The exact fault in that area. |
What to do next
- Note U0337 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0337
What does U0337 mean?
U0337 means "Software Incompatibility With Battery Charger Control Module A". Battery charger control module A is the charger built into a plug-in car: it turns mains AC into DC for the traction battery and coordinates with the charging station and the battery controller. It is a generic code, so it means the same on every make.
Is it safe to drive with U0337?
U0337 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0337 fail an emissions test?
Yes, it can. U0337 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is U0337 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U0337 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.