Vehicle May Not Restart — Battery Pack Voltage Mismatch

Common Symptoms

• Alert on the touchscreen: "Vehicle may not restart — Service is required"
• Vehicle typically still drives normally while the alert is present
• May appear alongside other BMS alerts

Probable Causes (Ranked by Likelihood)

• A mismatch between the measured high-voltage battery pack voltage and the value expected from individual cell measurements (Tesla's official description) — the BMS continuously monitors these values to ensure safe operation Likely
• Firmware-level alert name (BMS_a059_SW_Pack_Voltage_Sensing, per the firmware alert dictionary) confirms this is the BMS detecting a mismatch between pack voltage and the sum of individual cell-group voltages Possible

Step-by-Step Diagnostic Procedure

1. The battery management system cross-checks the whole pack's voltage against the sum of its individual cell-group measurements; this alert means those two numbers disagree beyond tolerance.

2. Per Tesla's official text, the vehicle is OK to drive in the meantime, but you should schedule service if the alert persists across drives — and the title warns the vehicle may not restart.

3. Don't park the vehicle somewhere hard to recover from while this alert is active, in case it doesn't restart.

4. Pack voltage diagnosis is Tesla-service-only work — never attempt high-voltage measurement or repair yourself.

Frequently Asked Questions