BMW i8 (2014–2020) Drivetrain No Restart & HV System Offline
Drivetrain warning message displayed
“Drivetrain. No restart” message
Non-start condition
High-voltage system offline
The following fault code(s) may be present
21F0CE – High-voltage battery unit: Terminal 30C, undervoltage
21F0CB – High-voltage battery unit: Crash message, serious crash detected
21F0C8 – High-voltage safety connector (Service Disconnect) disconnected
21F13D – High-voltage battery, switch contactors: Switch-off after a fault
21F142 – High-voltage battery: Control of switching contactor deactivated due to transport mode
Do you have a BMW i8 that won’t start or shows drivetrain warnings?
Don't ignore it. Book an initial inspection today and get expert help.
Parts Repaired or Replaced
- HV system
Affected Vehicles
BMW i8
- BMW i8 2014
- BMW i8 2015
- BMW i8 2016
- BMW i8 2017
- BMW i8 2018
- BMW i8 2019
- BMW i8 2020
Common Failure Symptoms
- Vehicle will not start
- Drivetrain warnings present
- High-voltage system offline
- Crash/impact message stored (despite no crash history)
BMW i8 Diagnostic Report
The vehicle arrived with a non-start complaint and multiple drivetrain-related warnings, so we carried out a structured diagnostic process to confirm the high-voltage system state, validate the reported symptoms, and identify the root cause affecting the HV battery power supply.
- Initially, the vehicle was presented in a non-start condition with drivetrain warnings
- Subsequently, diagnostic checks confirmed the high-voltage system was offline, with faults indicating a serious crash message and missing power supplies
- Further analysis revealed an electrical supply issue affecting the high-voltage battery power feed
BMW i8 Repairs
- First, we carried out wiring checks to locate the source of the missing supplies
- Next, we repaired the identified wiring fault feeding the high-voltage battery
- Finally, we completed the required high-voltage battery work, recommissioned the system, reassembled the vehicle, and verified correct operation
Resolution
Following completion of the wiring repair and high-voltage battery recommissioning, we carried out final checks to confirm the HV system was stable, all stored faults were cleared, and the vehicle would start and operate normally.
- High-voltage system brought back online and commissioned into service
- Faults addressed and vehicle returned to full operation
- Vehicle tested post-repair to confirm correct functionality
Need Help?
Are you an independent garage, dealership, warranty, fleet or insurance business?
Specialist Support for EV & Hybrid Repairs
We partner directly with independent garages, dealerships, warranty and fleet providers, and insurance companies across the UK to resolve complex EV and hybrid vehicle issues.
If your customer’s vehicle is displaying battery or electrical faults, we offer advanced diagnostics and expert repair solutions that go far beyond simple parts replacement.
Our battery and component repair service includes:
- Nationwide collection and delivery
- Rapid turnaround times
- Comprehensive technical support
Let us help you keep your customers on the road, while enhancing the value and reputation of your services.
Click below to find out how we can support you.
Is the vehicle owned by you or your business?
Have you been advised the battery or component needs replacing on your vehicle?
Before committing to a costly full replacement, talk to us. At LKQ Electriq, we specialise in inspecting, diagnosing and repairing complex battery and component faults (issues that many main dealers won’t touch).
Our expert repair service can restore your Range Rover’s hybrid battery at a fraction of the cost of replacement. We offer:
- Nationwide collection and delivery
- Transparent, honest assessments
- Specialist repairs backed by technical expertise
We’ve helped customers across the country save thousands. Book a diagnostic today and discover how we can help you get back on the road, without breaking the bank.
Click below to find out how we can support you.
Do LKQ Electriq repairs have a warranty?
High Voltage System Repairs
Repairs involving high voltage systems typically include a 12-month, unlimited mileage warranty, offering you complete peace of mind.*
Lifetime Guarantee
All work carried out at LKQ Electriq is backed by our lifetime workmanship guarantee.
*Terms and conditions apply. Please consult a Service Advisor to confirm the specific warranty details for your vehicle prior to booking.
0 Comments