EV Diagnostics
Verified EV diagnostic knowledge page

Ford Reverse Brake Assist Unavailable

Reverse Brake Assist Unavailable

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceFord service evaluation is appropriate because an official Ford manufacturer communication, TSB 25-2397, documents this condition for applicable vehicles.
Confidence90%

Quick answer

For certain 2021 Ford Mustang Mach-E vehicles in the US, Ford TSB 25-2397 documents a “Reverse Brake Assist Unavailable” message that may appear with missing active guidelines in the reverse-camera display. The bulletin also identifies DTC U0415:86 stored in the IPMA.

This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.

Video guides

Watch Videos

Relevant videos play here without leaving this diagnostic page.

No sufficiently relevant embeddable video has been accepted for this diagnostic yet.

Videos are supporting material and never override OEM or regulator evidence.

1. What does Reverse Brake Assist Unavailable mean?

For certain 2021 Ford Mustang Mach-E vehicles in the US, Ford TSB 25-2397 documents a “Reverse Brake Assist Unavailable” message that may appear with missing active guidelines in the reverse-camera display. The bulletin also identifies DTC U0415:86 stored in the IPMA.

2. Technical explanation

This is an OEM alert concerning Reverse Brake Assist. Verified evidence links the alert, on covered vehicles, with missing active guidelines in the reverse-camera display and diagnostic trouble code U0415:86 in the IPMA. The supplied evidence does not establish the underlying fault mechanism or a specific repair.

3. What system is affected?

Reverse Brake Assist; reverse-camera display; IPMA (as identified by the documented DTC location).

4. How serious is this code?

Unknown. The diagnostic record does not provide a severity rating.

5. Symptoms you may notice

  • “Reverse Brake Assist Unavailable” message displayed in the IPC.
  • Missing active guidelines in the reverse-camera display.
  • DTC U0415:86 stored in the IPMA.

6. Possible causes

  • Not yet established by verified evidence.

7. Can I still drive the vehicle?

Not yet established by verified evidence.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • Be aware that the Reverse Brake Assist feature is reported unavailable when this alert is displayed.
  • Use appropriate caution while reversing, particularly if reverse-camera active guidelines are missing.
  • Arrange Ford service evaluation if the message is present.

10. Step-by-step troubleshooting

  1. A service technician can check the IPMA for DTC U0415:86.
  2. The supplied evidence does not establish additional diagnostic steps.

11. When to contact service

Ford service evaluation is appropriate because an official Ford manufacturer communication, TSB 25-2397, documents this condition for applicable vehicles.

12. What the service center may check

  • Confirm whether the vehicle is a 2021 Ford Mustang Mach-E in the US.
  • Confirm the IPC displays “Reverse Brake Assist Unavailable.”
  • Check whether active guidelines are missing from the reverse-camera display.
  • Check the IPMA for DTC U0415:86.
  • Review Ford TSB 25-2397 for applicable service information.

13. Possible repair or resolution

  • Not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Ford TSB 25-2397, reported to NHTSA as Manufacturer Communication 11022396, published August 26, 2025. It documents that some listed vehicles may display “Reverse Brake Assist Unavailable” in the IPC with missing active reverse-camera guidelines and may store U0415:86 in the IPMA.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified official source: NHTSA Manufacturer Communication 11022396, Ford TSB 25-2397: https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11022396

19. Frequently asked questions

What does “Reverse Brake Assist Unavailable” mean on an applicable Mustang Mach-E?

Ford TSB 25-2397 documents this IPC message as a condition that may occur on certain covered vehicles. The bulletin also describes missing active guidelines in the reverse-camera display and U0415:86 stored in the IPMA.

Which vehicle is supported by the verified applicability evidence?

The supplied applicability evidence identifies the 2021 Ford Mustang Mach-E in the US.

Is there an official bulletin for this alert?

Yes. Ford TSB 25-2397 is listed in NHTSA Manufacturer Communication 11022396.

Does this alert affect charging?

Not yet established by verified evidence.

20. Sources & verification

Verified
Ford Reverse Brake Assist Unavailable: Reverse Brake Assist Unavailable | EV Diagnostics