Jaguar U0400
81 is set on the Driver Assistance Domain Controller (DADC). Cause: Software error. Action: Follow the instruction(s) below. SERVICE INSTRUCTION: If the symptoms match those in the
Quick answer
For certain 2021–2024 Jaguar I-PACE vehicles in the US, DTC U0400-81 may be stored in the Driver Assistance Domain Controller (DADC). Jaguar’s published communication identifies a software error and reports possible loss of power-steering assistance at the start of a drive cycle, with an ADAS warning message.
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 U0400 mean?
For certain 2021–2024 Jaguar I-PACE vehicles in the US, DTC U0400-81 may be stored in the Driver Assistance Domain Controller (DADC). Jaguar’s published communication identifies a software error and reports possible loss of power-steering assistance at the start of a drive cycle, with an ADAS warning message.
2. Technical explanation
The verified source identifies U0400-81 on the DADC in connection with a software error. The supplied evidence excerpt states that, where the vehicle symptoms match the bulletin situation, technicians should not replace parts before completing the specified diagnostic process.
3. What system is affected?
Driver Assistance Domain Controller (DADC), Advanced Driver Assistance Systems (ADAS), and power-steering assistance.
4. How serious is this code?
Potentially significant because the verified bulletin reports no power-steering assistance at the start of a drive cycle. The supplied evidence does not assign a formal severity rating.
5. Symptoms you may notice
- No power-steering assistance at the start of a drive cycle.
- ADAS warning message on the instrument panel.
- DTC U0400-81 stored on the Driver Assistance Domain Controller.
6. Possible causes
- Software error.
7. Can I still drive the vehicle?
Not yet established by verified evidence. Because the verified bulletin reports possible loss of power-steering assistance, use caution and seek Jaguar service guidance if this condition occurs.
8. Can I charge the vehicle?
Not yet established by verified evidence.
9. What you can safely do
- If an ADAS warning or loss of power-steering assistance occurs, arrange diagnosis by an authorized Jaguar service provider.
- Do not assume parts require replacement solely because U0400-81 is present; the verified Jaguar communication instructs technicians to complete its diagnostic steps first.
10. Step-by-step troubleshooting
- The verified service instruction directs technicians to run the Network Integrity Test (NIT) vehicle application.
- The supplied evidence excerpt also directs technicians to run the Power Steering diagnostic process, but the excerpt is truncated and does not provide the complete procedure.
- Do not perform high-voltage or steering-system repairs without qualified service support.
11. When to contact service
Contact an authorized Jaguar service provider, particularly if power-steering assistance is unavailable or an ADAS warning message is displayed.
12. What the service center may check
- Confirm whether the reported condition matches the bulletin situation: no power-steering assistance at the start of a drive cycle, an ADAS warning message, and U0400-81 stored on the DADC.
- Run the Network Integrity Test (NIT) vehicle application.
- Run the Power Steering diagnostic process referenced by Jaguar; the complete procedure is not included in the supplied evidence excerpt.
13. Possible repair or resolution
- The verified source identifies a software error.
- The supplied evidence does not establish the final repair, software version, update procedure, or outcome. Not yet established by verified evidence.
- Jaguar instructs technicians not to replace parts before completing the specified diagnostic steps when the symptoms match the bulletin situation.
14. Affected vehicles
- Jaguar I-Pace · 2021–2024 · US
15. Related TSBs / service bulletins
- Jaguar SSM76103, published through NHTSA as Manufacturer Communication PDF 10245031 on October 20, 2023. It applies to I-PACE 21MY onwards and reports U0400-81 on the DADC, possible no power-steering assistance at the start of a drive cycle, an ADAS warning, and a software error.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
NHTSA Manufacturer Communication PDF 10245031: SSM76103 — https://static.nhtsa.gov/odi/tsbs/2023/MC-10245031-0001.pdf
19. Frequently asked questions
What does U0400-81 mean for the Jaguar I-PACE?
In the verified Jaguar communication, U0400-81 is set on the Driver Assistance Domain Controller and is associated with a software error.
What symptoms are linked to U0400-81 in the verified bulletin?
The bulletin reports no power-steering assistance at the start of a drive cycle and an ADAS warning message on the instrument panel.
Should components be replaced immediately?
No. When the symptoms match the bulletin situation, Jaguar instructs technicians not to replace parts before completing the listed diagnostic steps.
Does this evidence confirm that the vehicle is safe to drive or charge?
No. Drive and charging status are not established by the supplied verified evidence.