HVREX_a743 — Bleed Fet Failure

Full alert identifier: HVREX_a743_BleedFetFailure

Alert description

A bleed Field-Effect Transistor (FET) on the Battery Management Board (BMB) is not operating as designed. This will prevent the battery from balancing the brick by decreasing the brick voltage.

Potential impact

There may be a decrease in available energy to the vehicle, reducing range and LV support.

Set condition

Upon a periodic wake, after an ECU reset, or every 6 hours, the Battery Management System (BMS) will test all bleed switches by switching them on in turn. If the sensed brick voltage does not significantly change, this alert is set.

Clear condition

The bleed test reports sufficient voltage change across each brick.

Signals to check

These diagnostic fields are associated with HVREX_a743. Check the alert's Alert Log in Service Mode Plus for available values.

Signal	Unit
Brick ID `HVREX_a743_brickID` 255 SNA	—
Delta V `HVREX_a743_deltaV`	V
Retry Count `HVREX_a743_retryCount`	—

Check other alerts

With Service Mode Plus enabled, open Service Alerts → All. Review the other alerts for clues to the cause of HVREX_a743.