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Ford U0155

built on or before 30-Sep-2021

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact a Ford dealer or qualified service provider for diagnosis, particularly if the stored codes match the condition described in TSB 25-2071.
Confidence95%

Quick answer

For certain 2021 US Ford Mustang Mach-E vehicles built on or before 30-Sep-2021, U0155 may be stored in the gear shift module (GSM). Ford TSB 25-2071 identifies GSM software as a possible reason in a condition also involving DTC U0103:87 in the secondary on-board diagnostic module (SOBDMC).

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.

DTC Ford U0155 Short ExplanationMaxidot
Ford u0155 problemas de comunicaciónThe Old Men Auto Repair

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

1. What does U0155 mean?

For certain 2021 US Ford Mustang Mach-E vehicles built on or before 30-Sep-2021, U0155 may be stored in the gear shift module (GSM). Ford TSB 25-2071 identifies GSM software as a possible reason in a condition also involving DTC U0103:87 in the secondary on-board diagnostic module (SOBDMC).

2. Technical explanation

Verified evidence from Ford TSB 25-2071, published by NHTSA, states that some vehicles may have U0103:87 stored in the SOBDMC and may also have U0100:00, U0121, U0140, and/or U0155 stored in the GSM. The bulletin states this may be due to software in the GSM. The supplied evidence does not establish the full generic definition of U0155, nor does it establish that every instance of U0155 has this cause.

3. What system is affected?

Gear shift module (GSM); the related bulletin also references the secondary on-board diagnostic module (SOBDMC).

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • U0155 may be stored in the GSM.
  • U0103:87 may be stored in the SOBDMC.
  • The verified evidence does not establish driver-observable symptoms.

6. Possible causes

  • For the condition described in Ford TSB 25-2071, software in the GSM may be the cause.
  • Other causes of U0155 are 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 Ford dealer or qualified service provider.
  • Provide the technician with DTC U0155 and Ford TSB 25-2071.
  • Do not attempt high-voltage system repairs or module programming yourself.

10. Step-by-step troubleshooting

  1. A service technician can confirm whether U0155 is stored in the GSM and whether U0103:87 is stored in the SOBDMC.
  2. A service technician can assess whether the vehicle and condition match Ford TSB 25-2071.
  3. Further diagnostic procedures are not established by the supplied verified evidence.

11. When to contact service

Contact a Ford dealer or qualified service provider for diagnosis, particularly if the stored codes match the condition described in TSB 25-2071.

12. What the service center may check

  • Confirm vehicle applicability: 2021 Ford Mustang Mach-E, US market, built on or before 30-Sep-2021.
  • Check for U0103:87 in the SOBDMC.
  • Check the GSM for U0155 and, where applicable, U0100:00, U0121, and U0140.
  • Review Ford TSB 25-2071 for the applicable service procedure.

13. Possible repair or resolution

  • The verified evidence identifies GSM software as a possible cause for the bulletin condition.
  • The specific repair or programming procedure is not included in the supplied evidence and is not yet established here.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Ford TSB 25-2071, published through NHTSA Manufacturer Communication 11015681 on 13-Mar-2025. It applies to the described model section for vehicles built on or before 30-Sep-2021 and identifies GSM software as a possible cause of the listed DTC condition.

16. Recall information

  • No recall information was supplied or established by verified evidence.

17. Official manufacturer information

NHTSA Manufacturer Communication 11015681 — Ford TSB 25-2071: https://static.nhtsa.gov/odi/ffdd/tsbs/TSBS_RECEIVED_2025-2026.zip#nhtsa_id=11015681

19. Frequently asked questions

What does U0155 mean for this Mustang Mach-E?

For the verified Ford bulletin condition, U0155 may be stored in the GSM on applicable vehicles. The supplied evidence does not establish the generic code definition.

Which vehicles are covered by the verified evidence?

2021 Ford Mustang Mach-E vehicles in the US, built on or before 30-Sep-2021.

Is GSM software a confirmed cause of every U0155 code?

No. TSB 25-2071 says GSM software may be the cause for its described condition; it does not establish this as the cause of every U0155 occurrence.

Can I continue driving or charging?

Not yet established by verified evidence.

20. Sources & verification

ReferenceVerified
Ford U0155: built on or before 30-Sep-2021 | EV Diagnostics