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Ford B1D55

31/49, and/or B15A5:56 DTCs return in the RFA after a self-test, follow normal Workshop Manual (WSM) diagnostics in Section 419-01. Repair

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceService evaluation is appropriate because the verified Ford instruction directs technicians to Workshop Manual diagnostics and repair. The need for immediate service is not otherwise established by verified evidence.
Confidence95%

Quick answer

For 2021–2024 Ford Mustang Mach-E vehicles in the US, B1D55 may be addressed by Ford SSM 54555 when it returns in the RFA after a self-test as B1D55:31/49. The verified instruction is to follow normal Workshop Manual diagnostics in Section 419-01 and repair as directed there.

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

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1. What does B1D55 mean?

For 2021–2024 Ford Mustang Mach-E vehicles in the US, B1D55 may be addressed by Ford SSM 54555 when it returns in the RFA after a self-test as B1D55:31/49. The verified instruction is to follow normal Workshop Manual diagnostics in Section 419-01 and repair as directed there.

2. Technical explanation

Verified evidence identifies B1D55 in Ford SSM 54555 in the form B1D55:31/49. The communication states that, after an FDRS session and verification that DTCs are no longer present, 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 diagnostics in Section 419-01 should be followed. The supplied evidence does not define the underlying component fault or a specific repair.

3. What system is affected?

The verified evidence refers to the RFA. The expanded name or exact vehicle function of RFA is not yet established by verified evidence.

4. How serious is this code?

Unknown. The supplied verified 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

  • Have a qualified Ford service facility evaluate the vehicle using the applicable Workshop Manual procedure in Section 419-01.
  • After an FDRS session, verify whether DTCs remain present and whether B1D55:31/49 returns in the RFA after a self-test, as described in Ford SSM 54555.

10. Step-by-step troubleshooting

  1. Ford SSM 54555 describes an FDRS session followed by verification that DTCs are no longer present.
  2. If only B1D55:31/49 and/or the other listed DTCs return in the RFA after a self-test, follow normal Workshop Manual diagnostics in Section 419-01.
  3. The detailed diagnostic steps within WSM Section 419-01 are not included in the supplied evidence.

11. When to contact service

Service evaluation is appropriate because the verified Ford instruction directs technicians to Workshop Manual diagnostics and repair. The need for immediate service is not otherwise established by verified evidence.

12. What the service center may check

  • Perform the applicable FDRS session referenced by Ford SSM 54555.
  • Verify whether DTCs are no longer present.
  • Run or review the RFA self-test result.
  • If only the listed codes return, use normal WSM Section 419-01 diagnostics.

13. Possible repair or resolution

  • Repair according to the result of normal Workshop Manual Section 419-01 diagnostics. A specific repair is not provided in the supplied verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Ford SSM 54555, published February 6, 2026, is documented by NHTSA Manufacturer Communication 11028797. It applies in the supplied data to 2021–2024 Ford Mustang Mach-E vehicles in the US and addresses B1D55:31/49 among the listed RFA self-test DTCs.

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 B1D55 mean on a Ford Mustang Mach-E?

The supplied evidence identifies B1D55:31/49 as a DTC that may return in the RFA after a self-test. It directs normal WSM Section 419-01 diagnostics; it does not provide a component-level definition.

Does Ford provide a specific repair for B1D55:31/49 in the supplied bulletin?

No specific repair is included in the supplied evidence. Ford directs technicians to follow normal Workshop Manual diagnostics in Section 419-01 and repair based on those results.

Is B1D55:31/49 covered by a recall?

Not yet established by verified evidence.

Can the vehicle be driven or charged with B1D55?

Not yet established by verified evidence.

20. Sources & verification

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