VCBATT_a474 — Left Headlamp Internal Error

Full alert identifier: VCBATT_a474_leftHeadlampInternalError

Alert description

An internal condition affecting left headlamp functionality has been detected - certain light functions or the headlamp fan may be degraded or disabled

Potential impact

Certain light functions or the headlamp fan may be degraded or disabled. These functions will retry after the next headlamp power cycle (which occurs during sleep)

Set condition

The SSL100 pixel matrix detects non-functional pixels or has communication issues, or the voltage measured across the boost rail, Lowbeam Prefield, DRL segments, or Turn LEDs (Model S only) is out of range, or the LED drivers in the ECU have reported status flags, or certain values programmed in the SSL100 EEPROM are out of range, or the fan current is out of range.

Clear condition

Headlamp power cycle

Signals to check

These diagnostic fields are associated with VCBATT_a474. Check the alert's Payload in Service Mode Plus for available values.

Signal	Unit
Boost Rail Status `VCBATT_a474_BoostRailStatus` 0 OK 1 FAULT	—
EEPROM Data Status `VCBATT_a474_EEPROM_DataStatus` 0 OK 1 FAULT	—
LMM Variant `VCBATT_a474_LMMVariant` 0 SNA 1 NOT LMM4 OR UNKNOWN 2 LMM4	—
Tps92520 bstuv `VCBATT_a474_TPS92520_BSTUV` 0 OK 1 FAULT	—
Tps92520 compov `VCBATT_a474_TPS92520_COMPOV` 0 OK 1 FAULT	—
Tps92520 hsilim `VCBATT_a474_TPS92520_HSILIM` 0 OK 1 FAULT	—
Drl 1 Status `VCBATT_a474_drl1Status` 0 OK 1 OVERVOLTAGE FAULT 2 UNDERVOLTAGE FAULT 3 DRIVER STATUS FAULT 4 OVERVOLTAGE FALSE TRIGGER 5 UNDERVOLTAGE FALSE TRIGGER 6 DRIVER STATUS FALSE TRIGGER	—
Drl 2 Status `VCBATT_a474_drl2Status` 0 OK 1 OVERVOLTAGE FAULT 2 UNDERVOLTAGE FAULT 3 DRIVER STATUS FAULT 4 OVERVOLTAGE FALSE TRIGGER 5 UNDERVOLTAGE FALSE TRIGGER 6 DRIVER STATUS FALSE TRIGGER	—

Show 14 more fields

Signal	Unit
Drl 3 Status `VCBATT_a474_drl3Status` 0 OK 1 OVERVOLTAGE FAULT 2 UNDERVOLTAGE FAULT 3 DRIVER STATUS FAULT 4 OVERVOLTAGE FALSE TRIGGER 5 UNDERVOLTAGE FALSE TRIGGER 6 DRIVER STATUS FALSE TRIGGER	—
Fan Status `VCBATT_a474_fanStatus` 0 OK 1 FAULT	—
Headlamp ECU Revision `VCBATT_a474_headlampECURevision`	—
Low Beam Prefield Status `VCBATT_a474_lowBeamPrefieldStatus` 0 OK 1 OVERVOLTAGE FAULT 2 UNDERVOLTAGE FAULT 3 DRIVER STATUS FAULT 4 OVERVOLTAGE FALSE TRIGGER 5 UNDERVOLTAGE FALSE TRIGGER 6 DRIVER STATUS FALSE TRIGGER	—
Ssl 100 Bank 1 Status `VCBATT_a474_ssl100Bank1Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Ssl 100 Bank 2 Status `VCBATT_a474_ssl100Bank2Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Ssl 100 Bank 3 Status `VCBATT_a474_ssl100Bank3Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Ssl 100 Bank 4 Status `VCBATT_a474_ssl100Bank4Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Ssl 100 Bank 5 Status `VCBATT_a474_ssl100Bank5Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Ssl 100 Bank 6 Status `VCBATT_a474_ssl100Bank6Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Ssl 100 Bank 7 Status `VCBATT_a474_ssl100Bank7Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Ssl 100 Bank 8 Status `VCBATT_a474_ssl100Bank8Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Ssl 100 Bank 9 Status `VCBATT_a474_ssl100Bank9Status` 0 OK 1 CRC ERROR 2 PIXEL ERROR 3 UNRESPONSIVE	—
Turn Signal Or DRL 4 Status `VCBATT_a474_turnSignalOrDRL4Status` 0 OK 1 OVERVOLTAGE FAULT 2 UNDERVOLTAGE FAULT 3 DRIVER STATUS FAULT 4 OVERVOLTAGE FALSE TRIGGER 5 UNDERVOLTAGE FALSE TRIGGER 6 DRIVER STATUS FALSE TRIGGER	—

Check other alerts

With Service Mode Plus enabled, open Service Alerts → All. Review the other alerts for clues to the cause of VCBATT_a474.