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U15ABModerateEV Charging / DC Fast Charging Communication

U15AB on 2021 Audi e-tron — Fast Battery Charging (DC) - Communication

1 vehicles · 1 makes

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How to diagnose and fix U15AB: most-reported vehicles

Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.

Audi e-tron · 2021–2021

Link to this issueError Codes:B1A86B1A87U1121U13AEU15ABP31CFP31E7U15ACP1A15U15B5P0CA4

Audi TSB 2061788/2 covers model-year 2021 e-tron quattro and e-tron Sportback vehicles with specified AC/DC charging interruptions, charging-flap operation problems, or an app request for auxiliary heating that does not pre-heat the vehicle when matching DTCs are stored in high-voltage battery charger control module J1050. Audi attributes the documented condition to onboard-charger software and identifies old software level 0070, not a proven failed charger module.

Common Symptoms

  • AC or DC charging is interrupted
  • DC charging does not start or stops at some stations
  • Charging-flap button is inoperative or the flap does not open
  • Auxiliary heating is activated through the app but the vehicle does not pre-heat

How to Fix

Record whether the failure is AC, DC or station-specific and have J1050 scanned before parts. If the vehicle has the matching condition and software level 0070, Audi directs an SVM update to software 0079 or higher. After the update, reproduce the concern and follow the guided test plan for any new active DTC. Do not infer hardware failure merely because one charging mode works, and do not order the former charger, 12-volt battery, relay, meter or portable EVSE from this card.

Owner tips & cautions

  • TipBring the failed station, date and charging mode to the diagnosis and ask for the J1050 software level and full DTC list before authorizing hardware.
Sources for this issue (1)
  • Audi TSB 2061788/2 - Charging Problems with Onboard-Charger Software 0070tsb

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High ConfidenceVerifiedReviewed Jul 2026

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Audi · 1 issue

U15AB code reference

General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.

Frequently asked questions

What does U15AB mean?

U15AB stands for "Fast Battery Charging (DC) - Communication." The onboard charger has a communication fault on the DC fast-charging link - the PLC/CCS handshake between the vehicle and the DC charging station is not completing or is dropping mid-session. The vehicle cannot negotiate or maintain the DC charging contract, so the session fails to start or is cut short. Audi TSB 2061788 lists U15AB00 among the DTCs stored in high-voltage battery charger J1050 on 2020-2021 e-tron quattro and e-tron Sportback with onboard-charger software 0070.

What are the most common causes of U15AB?

The most common causes of U15AB are: Outdated onboard-charger software (level 0070) - the documented remedy is the OBC software update per Audi TSB 2061788, Charging station firmware incompatibility or a station-side communication fault, Poor contact or debris in the CCS DC pins of the charging socket, Damaged communication wiring between the charge socket and J1050. The specific cause varies by vehicle.

How much does it cost to fix U15AB?

Repair costs vary widely depending on the root cause and vehicle.

Which vehicles are affected by U15AB?

Au7o has documented U15AB across 1 vehicle models from 1 manufacturers: Audi.

Related codes

  • U15AC · Signal Damping Log - Malfunction
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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