High-Voltage Battery Fault Diagnosis – Hybrid & EV Specialist UK

Hybrid or EV Battery Fault Code? Don’t Guess – We Diagnose It On-Site

High-voltage (HV) battery faults are among the most common – and critical – issues affecting hybrid and electric vehicles. Whether you’re dealing with a drivetrain malfunction, a vehicle that won’t start, or persistent warning lights, these faults can bring your journey to a halt.

If you’ve seen codes like 0316D6, 21F1F6, or 21F137, it’s time for proper diagnostics before it leads to a complete system failure.

📞 Mobile Support: 07421 186356
Covering London and major cities across England.

🔋 Understanding High-Voltage Battery Faults

High-voltage battery packs are the power source of modern hybrid and electric vehicles. They contain dozens – sometimes hundreds – of cells, controlled by a battery management system (BMS). Faults here can trigger:

  • 🔧 Drivetrain malfunction warnings

  • 🚫 No-start conditions

  • ⚠️ Limp mode activation

  • 🔋 Battery not charging

  • 🔌 EV-only mode disabled

🧾 Common High-Voltage Battery Fault Codes

Here are some of the most frequently logged fault codes related to HV battery faults:

  • 0316D6 / 0316D7 – Battery contactor issue; internal short or open circuit

  • 21F1F6 – Voltage outside of nominal range detected

  • 21F126 – One or more battery cells under-voltage or failed balancing

  • 21F137 – Over-voltage detected in battery cell(s)

  • 21F234 – General HV battery fault; possible BMS fault or internal temperature control error

These codes can appear on diagnostic scans of BMW i3, BMW X5e, Mercedes EQ Power hybrids, Toyota/Lexus hybrids, and other EVs like the Nissan Leaf, Hyundai Ioniq, and Kia EV6.

🧰 What We Offer

  • ✅ OEM-Level Diagnostics of high-voltage fault codes

  • ✅ Battery cell balancing and capacity testing

  • ✅ Contactor relay inspection and circuit testing

  • ✅ BMS communication analysis

  • ✅ On-site repair or module replacement when safe

  • ✅ Full documentation for warranty or insurance purposes

🚗 Models We Commonly Diagnose:

  • BMW i3 / i8 / X5 xDrive45e

  • Toyota Prius / Auris / RAV4 / CH-R Hybrid

  • Lexus CT200h / RX450h / NX300h

  • Hyundai Ioniq / Kona EV

  • Kia Niro Hybrid / EV6

  • Nissan Leaf / e-NV200

  • Mercedes GLE 350de / C300e

📍 Mobile High-Voltage Battery Diagnostics – Across the UK

Our technicians are qualified in high-voltage safety procedures and use hybrid/EV-specific diagnostic tools.

Service areas:

  • 🔧 London – All boroughs

  • 🔧 South East England – Kent, Surrey, Essex

  • 🔧 Midlands & North – Birmingham, Manchester, Leeds (by appointment)

  • 🔧 Emergency callouts available

📞 Book Your High-Voltage Battery Diagnosis Now

⚠️ These aren’t minor faults. If your vehicle shows HV battery issues, continuing to drive could risk permanent damage or render it undriveable.

📱 Call or WhatsApp: 07421 186356
🌐 www.fixanycar.co.uk
📍 Mobile hybrid & EV diagnostics at your location

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