EV Diagnostics
Verified EV diagnostic knowledge page

Ford B1A56

31/49, B1D55:31/49, and/or B15A5:56 DTCs return in the RFA after a self-test, follow normal Workshop Manual (WSM) diagnostics in Section 41

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceFord service is appropriate because the verified instruction directs Workshop Manual diagnostics after the specified RFA DTCs return following a self-test.
Confidence95%

Quick answer

For affected 2021–2024 Ford Mustang Mach‑E vehicles in the US, if B1A56:31/49 returns in the RFA after a self-test—alone or with B1D55:31/49 and/or B15A5:56—Ford directs technicians to follow normal Workshop Manual diagnostics in Section 41.

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 B1A56 mean?

For affected 2021–2024 Ford Mustang Mach‑E vehicles in the US, if B1A56:31/49 returns in the RFA after a self-test—alone or with B1D55:31/49 and/or B15A5:56—Ford directs technicians to follow normal Workshop Manual diagnostics in Section 41.

2. Technical explanation

Verified Ford/NHTSA service information states that after a new Ford Diagnosis and Repair System (FDRS) session, DTCs should be checked again. If only B1589:31/49 through B1598:31/49, B1A56:31/49, B1D55:31/49, and/or B15A5:56 return in the RFA after a self-test, normal Workshop Manual (WSM) diagnostics in Section 41 are to be followed. The supplied evidence does not establish the underlying fault mechanism for B1A56:31/49.

3. What system is affected?

RFA. The full expansion of RFA is not established by the supplied verified evidence.

4. How serious is this code?

Unknown. The supplied evidence does not assign a severity level.

5. Symptoms you may notice

  • Not yet established by verified evidence.

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

  • Arrange diagnosis by a qualified Ford service technician if the DTC is present or returns after a self-test.
  • Do not attempt high-voltage repair procedures based on this information.

10. Step-by-step troubleshooting

  1. Use a new Ford Diagnosis and Repair System (FDRS) session.
  2. Verify whether DTCs are no longer present.
  3. If only B1589:31/49 through B1598:31/49, B1A56:31/49, B1D55:31/49, and/or B15A5:56 return in the RFA after a self-test, follow normal Workshop Manual diagnostics in Section 41.

11. When to contact service

Ford service is appropriate because the verified instruction directs Workshop Manual diagnostics after the specified RFA DTCs return following a self-test.

12. What the service center may check

  • Perform a new FDRS session.
  • Verify DTC status after the FDRS session.
  • If the specified RFA DTCs return after a self-test, perform the applicable WSM Section 41 diagnostics.

13. Possible repair or resolution

  • Not yet established by verified evidence. The supplied communication directs normal WSM Section 41 diagnostics but does not provide a specific repair outcome.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Ford SSM 54555, NHTSA Manufacturer Communication 11028797, published February 6, 2026. It instructs technicians to use a new FDRS session, verify DTC status, and use WSM Section 41 diagnostics if only the specified RFA DTCs return after a self-test.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official source: NHTSA Manufacturer Communication 11028797, Ford SSM 54555: https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11028797

19. Frequently asked questions

What does B1A56 mean for this Ford Mustang Mach-E application?

The verified communication identifies B1A56:31/49 as an RFA DTC addressed by its diagnostic instruction. It does not define the fault mechanism.

What should happen if B1A56:31/49 returns after an RFA self-test?

Ford directs normal Workshop Manual diagnostics in Section 41 when only the listed DTCs return after a new FDRS session and self-test.

Does this information say the vehicle is unsafe to drive or charge?

No. Driveability and charging safety are not established by the supplied verified evidence.

20. Sources & verification

Verified
Ford B1A56: 31/49, B1D55:31/49, and/or B15A5:56 DTCs return in the RFA… | EV Diagnostics