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Ford U0103

87 stored in the secondary on board diagnostic module (SOBDMC). Some vehicles may also exhibit DTCs U0100:00, U0121, U0140, and/or U0155 st

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact a Ford dealer or qualified Ford service provider for evaluation. The supplied official bulletin summaries associate this condition with service-required messaging, but do not establish whether the vehicle can be safely driven or charged.
Confidence95%

Quick answer

For certain 2021 US Ford Mustang Mach-E vehicles, official Ford TSBs document DTC U0103:87 stored in the Secondary On-Board Diagnostic Module C (SOBDMC), often with a wrench warning lamp and/or a “Shift System Fault” message. Service is indicated by the bulletin evidence, but driveability and charging safety are not established by the supplied evidence.

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 U0103 mean?

For certain 2021 US Ford Mustang Mach-E vehicles, official Ford TSBs document DTC U0103:87 stored in the Secondary On-Board Diagnostic Module C (SOBDMC), often with a wrench warning lamp and/or a “Shift System Fault” message. Service is indicated by the bulletin evidence, but driveability and charging safety are not established by the supplied evidence.

2. Technical explanation

The supplied verified evidence identifies U0103:87 as being stored in the SOBDMC on applicable vehicles. Ford communications also state that some vehicles may have U0100:00, U0121, U0140, U0155, and/or additional unspecified codes stored. The evidence supplied does not establish a general plain-language definition, root cause, or diagnostic procedure for U0103 beyond this bulletin-specific condition.

3. What system is affected?

Secondary On-Board Diagnostic Module C (SOBDMC).

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • Illuminated powertrain malfunction indicator (wrench) lamp.
  • “Shift System Fault” message.
  • A 2021 bulletin summary references “Shift System Fault — Service required.”

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 Ford service or diagnostic evaluation, as the verified TSB evidence references a service-required condition.
  • Record any displayed messages and warning lamps for the service visit.
  • Do not attempt high-voltage-system repairs based on this information.

10. Step-by-step troubleshooting

  1. Confirm whether DTC U0103:87 is stored in the SOBDMC.
  2. Check whether the vehicle exhibits the documented wrench lamp and/or “Shift System Fault” message.
  3. Check for the additional codes specifically named in the TSB evidence: U0100:00, U0121, U0140, and U0155.
  4. Have a Ford service provider determine whether the vehicle and condition meet the complete bulletin criteria.

11. When to contact service

Contact a Ford dealer or qualified Ford service provider for evaluation. The supplied official bulletin summaries associate this condition with service-required messaging, but do not establish whether the vehicle can be safely driven or charged.

12. What the service center may check

  • Retrieve diagnostic trouble codes and verify U0103:87 is stored in the SOBDMC.
  • Document presence or absence of the wrench lamp and “Shift System Fault” message.
  • Check for U0100:00, U0121, U0140, and U0155 as identified in the official bulletin summaries.
  • Verify vehicle applicability and complete bulletin eligibility using the full Ford TSB documentation.

13. Possible repair or resolution

  • Not yet established by verified evidence. The supplied excerpts identify the condition but do not provide the Ford repair procedure or resolution.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Ford TSB 25-2071, published March 13, 2025; NHTSA Manufacturer Communication 11015681. The supplied summary documents U0103:87 in the SOBDMC with a wrench lamp and/or “Shift System Fault” message, with possible U0100:00, U0121, U0140, and/or U0155.
  • Ford TSB 21-2405, published November 17, 2021; NHTSA Manufacturer Communication 10203653. The supplied summary documents U0103:87 in the SOBDMC with a wrench lamp and/or “Shift System Fault — Service required” message, with possible U0100:00, U0121, U0140, and/or U0155.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified applicability supplied: 2021 Ford Mustang Mach-E, US. Official sources: NHTSA Manufacturer Communication 11015681 (Ford TSB 25-2071) and NHTSA Manufacturer Communication 10203653 (Ford TSB 21-2405).

19. Frequently asked questions

What does U0103:87 mean on a 2021 Ford Mustang Mach-E?

The supplied Ford TSB evidence identifies U0103:87 as stored in the Secondary On-Board Diagnostic Module C (SOBDMC). A broader meaning is not established by the supplied evidence.

What warnings can occur with U0103:87?

The verified bulletin summaries list an illuminated wrench lamp and/or a “Shift System Fault” message. One summary specifically references “Shift System Fault — Service required.”

Can I drive or charge with U0103:87?

Not yet established by verified evidence. Seek Ford service evaluation.

Which other codes may appear with U0103:87?

The supplied official summaries state that U0100:00, U0121, U0140, and/or U0155 may also be stored.

20. Sources & verification

ReferenceVerified
Ford U0103: 87 stored in the secondary on board diagnostic module… | EV Diagnostics