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Jaguar U2109-09

up Battery Voltage is too low. Cause: Issue is caused due to TCU using the Back Up Battery when 12V Vehicle Battery is flat. Action: CAUTION: Do not replace the Back-up Battery. Pl

Common search variants: U210909 · U2109 09 · U2109_09 · Search ignores case and common separators.

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact an authorized Jaguar service provider for diagnosis following SSM75646, particularly if U2109-09 or an SOS availability warning is present.
Confidence95%

Quick answer

For applicable 2019–2020 US Jaguar I‑PACE vehicles, U2109-09 may indicate that the TCU3 back-up battery voltage is too low. Jaguar’s communication attributes this to the TCU using the back-up battery when the 12 V vehicle battery is flat. Do not replace the back-up battery based on this communication; follow the Jaguar SSM procedure.

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 U2109-09 mean?

For applicable 2019–2020 US Jaguar I‑PACE vehicles, U2109-09 may indicate that the TCU3 back-up battery voltage is too low. Jaguar’s communication attributes this to the TCU using the back-up battery when the 12 V vehicle battery is flat. Do not replace the back-up battery based on this communication; follow the Jaguar SSM procedure.

2. Technical explanation

NHTSA-hosted Jaguar communication SSM75646 states that TCU3 can trigger U2109-09 when back-up battery voltage is too low. The communication identifies a flat 12 V vehicle battery as the cause described: the TCU uses the back-up battery when the 12 V vehicle battery is flat. The specified action is to use a JLR-approved diagnostic tool and JLR-approved battery support unit and follow the SSM procedure.

3. What system is affected?

Telematics Module (TCU3), including its back-up battery function and SOS warning capability.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • “SOS Limited Availability” warning in the cluster display.
  • “SOS Not Available” warning in the cluster display.
  • DTC U2109-09 may be triggered when back-up battery voltage is too low.

6. Possible causes

  • Jaguar states that the condition is caused by the TCU using the back-up battery when the 12 V vehicle battery is flat.

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

  • Do not replace the back-up battery based on Jaguar communication SSM75646.
  • Arrange diagnosis using a JLR-approved diagnostic tool and JLR-approved battery support unit.
  • Follow the applicable Jaguar SSM procedure.

10. Step-by-step troubleshooting

  1. Confirm whether the cluster displays “SOS Limited Availability” or “SOS Not Available.”
  2. Check for stored U2109-09 using a JLR-approved diagnostic tool.
  3. Follow Jaguar’s SSM procedure with a JLR-approved battery support unit.

11. When to contact service

Contact an authorized Jaguar service provider for diagnosis following SSM75646, particularly if U2109-09 or an SOS availability warning is present.

12. What the service center may check

  • Use a JLR-approved diagnostic tool.
  • Use a JLR-approved battery support unit.
  • Follow the applicable Jaguar SSM procedure.
  • Assess the reported low-voltage condition involving the 12 V vehicle battery and TCU back-up battery as directed by the SSM.

13. Possible repair or resolution

  • Do not replace the back-up battery solely for this condition; Jaguar explicitly cautions against replacement in SSM75646.
  • The final repair resolution is not yet established by the verified evidence because the referenced SSM procedure content was not supplied.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Jaguar SSM75646, published January 18, 2022, NHTSA Manufacturer Communication PDF 10207590. It addresses TCU3 SOS limited/not available warnings and possible U2109-09 caused by low back-up battery voltage in the stated scenario.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified official source: NHTSA-hosted Jaguar Manufacturer Communication PDF 10207590, SSM75646, published January 18, 2022: https://static.nhtsa.gov/odi/tsbs/2022/MC-10207590-0001.pdf. Verified applicability: 2019–2020 Jaguar I‑PACE, US market.

19. Frequently asked questions

What does U2109-09 mean on a Jaguar I‑PACE?

For the verified Jaguar communication, U2109-09 may be triggered when the TCU3 back-up battery voltage is too low.

Why can U2109-09 occur?

Jaguar states that the TCU uses the back-up battery when the 12 V vehicle battery is flat.

Should the TCU back-up battery be replaced?

No. SSM75646 specifically cautions not to replace the back-up battery.

Is it safe to drive or charge with U2109-09?

Not yet established by verified evidence.

20. Sources & verification

Verified
Jaguar U2109-09: up Battery Voltage is too low. Cause: Issue is caused… | EV Diagnostics