Maximum Battery Charge Level and Range Reduced
The TESLA-BMS_A074 (Tesla BMS (Battery Management System)) EV fault code means: Maximum Battery Charge Level and Range Reduced. This is a serious severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- expert
- Estimated cost
- Diagnosed and quoted by Tesla service; depends on the internal battery condition found. Battery-related repairs may be covered by the battery and drive unit warranty (8 years on current models, with mileage caps that vary by model) — check your coverage before paying out of pocket.
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Common Symptoms
- Alert on the touchscreen: "Maximum battery charge level reduced — OK to drive - Schedule service"
- Charging will not start if the state of charge is already above 50%
- Charging works when the state of charge is below 50%
- Reduced maximum range
Probable Causes (Ranked by Likelihood)
- A condition internal to the high-voltage battery pack that is limiting the battery's performance and capping its maximum charge level (Tesla's official description — the specific internal cause is determined at service) Likely
Step-by-Step Diagnostic Procedure
The battery management system has capped the pack's maximum charge level to protect it. Per Tesla's official text, the vehicle can charge when the state of charge is below 50%, but charging will not start above 50%.
There is no owner-serviceable fix — high-voltage pack work is Tesla-service-only. Schedule service at your earliest convenience.
Without service, Tesla's guidance is that maximum charge level and range may be reduced further.
Plan trips around the reduced usable capacity until the vehicle is serviced.
Frequently Asked Questions
What does BMS_a074 mean on a Tesla?
Tesla's official meaning: the vehicle has detected a condition internal to the high-voltage battery that is limiting its performance, so the maximum charge level and range are reduced. Service is required to restore full performance.
Why won't my Tesla charge above 50% with BMS_a074?
The battery management system has capped the maximum charge level to protect the pack. Per Tesla's official text, the vehicle charges normally below 50% state of charge, but charging will not start if the battery is already above 50%.
Can I keep driving with BMS_a074?
Yes — Tesla says the vehicle is OK to drive. Schedule service at your earliest convenience; without it, the maximum charge level and range may drop further.
Sources
This page is built from documented references. Verify against your own service info before repair work.