Powertrain, generic · Hybrid propulsion

P0CA4 Hybrid/EV Battery Charging Voltage High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0CA4 is stored when the traction battery voltage climbs above its permitted limit while energy flows into the pack, for instance because a charger or the drive keeps pushing current although the cells are already full. Audi lists the code in TSB 2062631/5 from 2024 for the e-tron and Q8 e-tron family, there stored by the high-voltage charger module J1050 and described as an excessive battery load voltage. In that case it is one of several ghost entries produced by charger software, found without any customer complaint, and the bulletin says it can be ignored. CARB section (e)(15.2.3) requires monitoring of the energy storage system and of the onboard charger of plug-in vehicles. A real overvoltage normally appears together with cell codes such as P0DE7, and charging is then interrupted.

Likely causes

Charger or battery control software storing a false entry (Audi 2062631/5)
Charging current not reduced in time as the pack approaches full charge
Faulty pack or cell voltage measurement in the battery management

Symptoms

  • Charging stops early or does not start
  • Code found during a check without any noticeable symptom

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€0–1,500
Time0.5–3 h

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

Parts involved

hv batterybms

Related codes

P0CA5P0CA6P0AFBP0DE7P0D28

References: static.nhtsa.gov, law.cornell.edu.