2023-2024 Tesla Model Y HVIL Alerts TSB SB-25-17-005

Symptoms

Owners of 2023-2024 Tesla Model Y vehicles may experience intermittent or false High Voltage Interlock Loop (HVIL) alerts. These alerts are triggered when the center high mounted stop light interferes with the power supply line for the High Voltage Controller (HVC). This electrical interference can lead to unexpected warnings on the vehicle's display.

Fault Codes / OEM Labels

When this condition occurs, the vehicle's diagnostic system may log specific fault codes or display OEM fault labels. These include:

• "HVP_w026_HvilFault"
• "BMS_a036_SW_HvpHvilFault"

These codes indicate an issue within the high voltage system, specifically related to the HVIL circuit.

Diagnosis / Trigger Conditions

Technicians will inspect the vehicle for symptoms related to the described condition. The interference is specifically linked to the center high mounted stop light's proximity and electrical interaction with the HVC power supply line. If the vehicle is presenting the aforementioned Tesla Model Y HVIL alerts, the service bulletin recommends a specific correction.

Repair Procedure Summary

Tesla Service Bulletin SB-25-17-005 outlines a procedure to resolve the interference causing the Tesla Model Y HVIL alerts. The repair involves installing a ferrite core onto the High Voltage Controller (HVC) electrical harness. This ferrite acts as an electromagnetic interference (EMI) filter, preventing the stop light's electrical signals from disrupting the HVC's power supply.

The general steps for this correction include:

1. Disconnecting the low voltage (LV) power to ensure safety.
2. Removing the right-hand lower C-pillar trim to gain access to the HVC connector.
3. Disconnecting the HVC connector and installing a protective cap.
4. Carefully removing a section of electrical tape from the HVC electrical harness.
5. Locating the thickest tan wire within the harness branch and installing a ferrite core onto it.
6. Securing the ferrite core with electrical tape, ensuring it rests on the vehicle body to prevent noise, vibration, and harshness (NVH) issues.
7. Reconnecting the HVC connector and removing the protective cap.
8. Reinstalling the C-pillar trim and other components.
9. Reconnecting the LV power.

Required Tools or Parts

To perform the repair described in Service Bulletin SB-25-17-005, the following parts and special tools are required:

• Parts Required:
  • 1479450-00-A: FERRITE (Quantity: 1)
• Special Tools:
  • 1108272-00-B: CAP, LOGIC CONN, INV, 3DU
• Shop Supplies:
  • 1922330-00-A: TAPE, PET FLEECE, RUBBER

Important Warnings

Owners and technicians should be aware of the following critical advisories from the service bulletin:

• "CAUTION: Make sure not to damage any wires or wire insulation."
• "NOTE: Rotate the ferrite around the wire to confirm that it is installed correctly and isn't pinching any wires."
• "NOTE: Apply sufficient tape and position the ferrite to rest on the vehicle body to prevent NVH issues. Apply an extra layer of tape if necessary."
• The bulletin also states: "This part number was current at the time of publication. Use the revision listed or later, unless otherwise specified in the Parts Catalog."

Owner Action

If your 2023-2024 Tesla Model Y is displaying "HVP_w026_HvilFault" or "BMS_a036_SW_HvpHvilFault" alerts, or if you suspect you are experiencing false High Voltage Interlock Loop alerts, it is recommended to contact a Tesla Service Center. Reference Service Bulletin SB-25-17-005 when scheduling your appointment. The repair involves a specific procedure performed by trained professionals and typically takes approximately 0.3 hours.

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Source: NHTSA ID: 11014773