Network, generic

U0295 Lost Communication With AC/AC Converter Control Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

An AC/AC converter takes in alternating current and delivers alternating current at a different voltage or frequency, with no DC storage in between. In electric vehicles such a stage can be part of a charger: in patent US9973107B2 a matrix stage converts the three mains phases directly to a high-frequency waveform, which an isolating transformer passes on before rectification for the battery. Other uses are possible, for example adapting power for on-board outlets. U0295 means the module controlling that converter has fallen silent on the network. No manufacturer documents U0295, and public service literature contains no module of this name; what it does is up to the vehicle design. If it sits in the charging path, CARB requires plug-in hybrids to detect faults that stop or slow charging.

Likely causes

Low-voltage supply or wake-up of the converter module missing
Bus wiring or connector to the converter damaged
Converter shut down after overheating or a coolant fault
Converter control module internally failed

Symptoms

  • AC charging not possible or interrupted
  • Charging or power supply warning

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,000
Time0.5–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

ac ac converter modulevehicle bus wiring

Related codes

U0596U0296U0288

References: patents.google.com, law.cornell.edu, en.wikipedia.org.