VCFRONT_a414 — Precharge LV Load Reduction

Full alert identifier: VCFRONT_a414_prechargeLVLoadReduction

Alert description

Low Voltage (LV) bus load reduction activated due to inability to precharge the High Voltage (HV) bus.

Potential impact

The Autopilot Electronic Control Unit (ECU), Media Control Unit (MCU), headlight, and sleep bypass LV power feeds are powered off (eFuses gating these power feeds are opened to reduce LV bus load).

Set condition

The vehicle controller detects HV bus precharge is unsuccessful due to low LV Bus voltage.

Clear condition

HV bus precharge succeeds or LV bus load reduction times out.

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
IBS Amp Hours `VCFRONT_a414_IBSAmpHours`	Ah
IBS Current `VCFRONT_a414_IBSCurrent`	A
IBS Voltage `VCFRONT_a414_IBSVoltage`	V
LV Battery Temp `VCFRONT_a414_LVBatteryTemp` 127 SNA	degC
Dcr Milli Ohms `VCFRONT_a414_dcrMilliOhms`	mOhms

Signal	Unit
Vehicle Power State `VCFRONT_a414_vehiclePowerState` 0 OFF 1 CONDITIONING 2 ACCESSORY 3 DRIVE	—

Check other alerts

With Service Mode Plus enabled, open Service Alerts → All. Review the other alerts for clues to the cause of VCFRONT_a414.