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Mitsubishi P1AA4

CMU ID change (CMU10), P1AA5: CMU ID change (CMU11), P1AA6: CMU ID change (CMU12), . TROUBLE JUDGMENT Check Conditions  When the CMUs are numbered for identification.  Either one

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceService need is not explicitly established by the supplied evidence. Because this code concerns CMU identification in the main drive lithium-ion battery documentation, qualified Mitsubishi EV service evaluation is appropriate; no high-voltage repair procedure is provided here.
Confidence95%

Quick answer

For applicable 2012 and 2014 US-market Mitsubishi i-MiEV vehicles, DTC P1AA4 identifies a CMU ID change for CMU10. The supplied evidence does not establish drivability, charging safety, symptoms, a repair, or a specific cause beyond the CMU identification-numbering context.

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 P1AA4 mean?

For applicable 2012 and 2014 US-market Mitsubishi i-MiEV vehicles, DTC P1AA4 identifies a CMU ID change for CMU10. The supplied evidence does not establish drivability, charging safety, symptoms, a repair, or a specific cause beyond the CMU identification-numbering context.

2. Technical explanation

Mitsubishi service information cited in NHTSA manufacturer communications TSB-19-54-003 and TSB-19-54-004 lists P1AA4 as “CMU ID change (CMU10).” The same diagnostic group covers CMU ID-change codes P1A9B through P1AA6 for CMU01 through CMU12. The supplied excerpt states that the trouble judgment check condition occurs when CMUs are numbered for identification and references U1925, “CMU ID numbering reception error,” as part of the diagnostic conditions. The complete judgment criteria, diagnostic procedure, and corrective action are not included in the supplied evidence.

3. What system is affected?

The evidence identifies the condition as involving CMU10 and CMU identification numbering. A broader system name is not established by the supplied 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

  • CMU identification-numbering context involving CMU10 is verified.
  • A specific underlying failure cause is 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

  • Record the exact DTC and vehicle details.
  • Have the vehicle evaluated using applicable Mitsubishi service information by qualified EV service personnel.
  • Do not attempt high-voltage battery or CMU repair based on this information.

10. Step-by-step troubleshooting

  1. Verify that P1AA4 is present with an appropriate diagnostic tool.
  2. Review related diagnostic information for CMU identification numbering, including the referenced U1925 condition, using the applicable Mitsubishi service procedure.
  3. Further diagnostic steps are not established by the supplied verified evidence.

11. When to contact service

Service need is not explicitly established by the supplied evidence. Because this code concerns CMU identification in the main drive lithium-ion battery documentation, qualified Mitsubishi EV service evaluation is appropriate; no high-voltage repair procedure is provided here.

12. What the service center may check

  • Confirm P1AA4: CMU ID change (CMU10).
  • Review whether U1925, described in the supplied TSB excerpt as “CMU ID numbering reception error,” is stored or relevant under the applicable procedure.
  • The detailed service checks and acceptance criteria are not included in the supplied evidence.

13. Possible repair or resolution

  • Not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Mitsubishi TSB-19-54-003, published March 13, 2019, is provided through NHTSA Manufacturer Communication PDF 10158408 and includes P1AA4 in its CMU ID-change diagnostic group.
  • Mitsubishi TSB-19-54-004, published March 13, 2019, is provided through NHTSA Manufacturer Communication PDF 10158409 and includes P1AA4 in its CMU ID-change diagnostic group.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified official source: NHTSA-hosted Mitsubishi manufacturer communications TSB-19-54-003 and TSB-19-54-004, both published March 13, 2019. https://static.nhtsa.gov/odi/tsbs/2019/MC-10158408-9999.pdf ; https://static.nhtsa.gov/odi/tsbs/2019/MC-10158409-9999.pdf

19. Frequently asked questions

What does P1AA4 mean on an applicable Mitsubishi i-MiEV?

It means “CMU ID change (CMU10)” according to the supplied Mitsubishi service-information excerpts.

Which vehicles are verified as applicable?

US-market 2012 and 2014 Mitsubishi i-MiEV vehicles are listed in the supplied applicability evidence.

Is it safe to drive or charge with P1AA4?

Not yet established by verified evidence.

Does P1AA4 prove that CMU10 has failed?

No. The supplied evidence identifies a CMU10 ID-change condition but does not establish a specific failed component or underlying cause.

20. Sources & verification

Verified
Mitsubishi P1AA4: CMU ID change (CMU10), P1AA5: CMU ID change (CMU11),… | EV Diagnostics