Is EFUSE_W159 the same as EFUSE-W159?

Yes. EFUSE_W159, EFUSE W159, and EFUSE-W159 are alternate spellings of the same Tesla alert code. Also written as: EFUSE-W159, EFUSE_W159, EFUSE W159, EFUSE_w159_revBattFaulted, efuse_w159_revbattfaulted.

What symptoms can EFUSE-W159 cause?

Electronic Fuse alert: This alert is intended to show that the 12V battery was connected in reverse-polarity (negative post to positive harness Related vehicle feature may be reduced or unavailable Alert visible in the Tesla app: This alert is intended to show that the 12V battery was connected in reverse-pol

What should I check for EFUSE-W159?

1. Reboot the vehicle by holding both scroll wheels for 10 seconds 2. Check for pending OTA software updates in Controls > Software 3. If the alert persists, schedule a Tesla Service appointment 4. Describe the alert code and any symptoms when booking service

Is it safe to drive with EFUSE-W159?

🟡 Check the vehicle display for drive or charge restrictions and schedule service promptly.

TESLA Warning

EFUSE-W159

EFUSE_w159_revBattFaulted

Also written as EFUSE_W159 / EFUSE W159 / EFUSE_w159_revBattFaulted / efuse_w159_revbattfaulted

System

EFUSE

Electronic Fuse

Type

Warning

Why does the exact Tesla alert ID matter?

Record the exact alert ID, including underscores, suffixes, and companion alerts. Tesla alerts that look similar can point to different modules, timestamps, and service procedures.

What does EFUSE-W159 mean?

Tesla warning code in the Electronic Fuse (EFUSE) module. This alert is intended to show that the 12V battery was connected in reverse-polarity (negative post to positive harness and vice-versa) but can trigger during normal operation, which is not expected and is currently being investigated. For now, this alert can be ignored. This alert triggered if the reverse battery E-fuse is tripped. It is sometimes triggered along with EFUSE_w148_cabinOverCurrent and EFUSE_w147_frunkOverCurrent as well.

Original Description

This alert is intended to show that the 12V battery was connected in reverse-polarity (negative post to positive harness and vice-versa) but can trigger during normal operation, which is not expected and is currently being investigated. For now, this alert can be ignored. This alert triggered if the reverse battery E-fuse is tripped. It is sometimes triggered along with EFUSE_w148_cabinOverCurrent and EFUSE_w147_frunkOverCurrent as well.

Affected Tesla Models

Model SModel XModel 3Model Y

What You May Notice

Electronic Fuse alert: This alert is intended to show that the 12V battery was connected in reverse-polarity (negative post to positive harness
Related vehicle feature may be reduced or unavailable
Alert visible in the Tesla app: This alert is intended to show that the 12V battery was connected in reverse-pol

How to Diagnose and Resolve

1 Reboot the vehicle by holding both scroll wheels for 10 seconds
2 Check for pending OTA software updates in Controls > Software
3 If the alert persists, schedule a Tesla Service appointment
4 Describe the alert code and any symptoms when booking service

Severity Notes

EFUSE-W159 is a Warning in the Electronic Fuse system. Schedule service soon. Monitor your vehicle for additional warnings.

Other EFUSE Codes

EFUSE_w001 EFUSE_w010 Tesla warning code in the Electronic Fuse (EFUSE) module. Th... EFUSE_w012 Tesla warning code in the Electronic Fuse (EFUSE) module. Th... EFUSE_w013 EFUSE_w015 EFUSE_w021 EFUSE_w022 EFUSE_w041

View all EFUSE codes →