P0CA4 on 2021 Audi e-tron — Hybrid / High-Voltage Battery Charging Voltage Too High
1 vehicles · 1 makes
Most Reported On
P0CA4 is an OBD-II diagnostic trouble code meaning “Hybrid / High-Voltage Battery Charging Voltage Too High.” The onboard charger control module has measured a charging voltage above the permitted limit for the high-voltage battery and aborts or refuses the charging session to protect the pack. Audi TSBs 2061788 and 2062631 list DTC P0CA400 ("Hybrid/high voltage battery load voltage too high") among the codes stored in high-voltage battery charger J1050 on 2020-2021 e-tron quattro and e-tron Sportback that are attributable to old onboard-charger software (level 0070) rather than to failed charging hardware. This code is most commonly reported on 2021 Audi e-tron.
Common Causes
Diagnostic Tools
This is a powertrain code, so a basic OBD-II reader can read it. These read P0CA4.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.
- Read & clear engine (P) codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X V3.0 Elite OBD-II Scanner
by LAUNCH
Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
What you can do yourself, and what needs a shop
Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:
- Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
- Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
- Airbag/SRS component work — a stored fault can deploy a live device.
If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.
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FAQ
What does P0CA4 mean?
P0CA4 stands for "Hybrid / High-Voltage Battery Charging Voltage Too High." The onboard charger control module has measured a charging voltage above the permitted limit for the high-voltage battery and aborts or refuses the charging session to protect the pack. Audi TSBs 2061788 and 2062631 list DTC P0CA400 ("Hybrid/high voltage battery load voltage too high") among the codes stored in high-voltage battery charger J1050 on 2020-2021 e-tron quattro and e-tron Sportback that are attributable to old onboard-charger software (level 0070) rather than to failed charging hardware.
What are the most common causes of P0CA4?
The most common causes of P0CA4 are: Outdated onboard-charger software - Audi documents software 0070 as producing this and other "ghost" DTCs (TSB 2061788 / 2062631), Charging station delivering out-of-spec voltage, Faulty voltage measurement inside the onboard charger, High-voltage battery management or contactor fault. The specific cause varies by vehicle.
How much does it cost to fix P0CA4?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P0CA4?
Au7o has documented P0CA4 across 1 vehicle models from 1 manufacturers: Audi.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.