BMS_f038 — SW Neg Contactor

Full alert identifier: BMS_f038_SW_Neg_Contactor

Message shown in the car

Unable to start vehicle Service is required

Alert description

The battery management system (BMS) detects that the negative contactor remains open during the first 2 seconds of pack contactors attempting to close.

Potential impact

Inability to charge, drive, or support the low voltage (LV) system

Set condition

The BMS detects that the negative pack contactor is welded.

Clear condition

The negative contactor closes as expected.

Signals to check

Open this alert in Service Mode Plus and review the Payload tab. Use the field names below to identify the values shown by your vehicle.

Signal	Unit
Vdiff `BMS_a038_Vdiff` -32768 SNA	V
Coil Current `BMS_a038_coilCurrent` 255 SNA	A
Vehicle 12 V `BMS_a038_vehicle12V` 255 SNA	V

Signal	Unit
Contactor State `BMS_a038_contactorState`	—
Ctr `BMS_a038_ctr` 0 DR POS 1 DR NEG 2 ANC POS 3 ANC NEG 4 FC POS 5 FC NEG 6 UNDEF	—
Ctr Err Type `BMS_a038_ctrErrType` 0 OPENED FAILURE 1 WELDED 2 EEPROM 3 DRIVESHORT PULLIN 4 COILIMPEDANCE REDUCED 5 DRIVEOPEN PULLIN 6 UNEXPECTED DRIVECURRENT	—

Check other alerts

With Service Mode Plus enabled, open Service Alerts → All. Review the other alerts for clues to the cause of BMS_f038.