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Mitsubishi P1AA3

CMU ID change (CMU09), P1AA4: CMU ID change (CMU10), P1AA5: CMU ID change (CMU11), P1AA6: CMU ID change (CMU12), . TROUBLE JUDGMENT Check Conditions  When the CMUs are numbered fo

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceProfessional evaluation is appropriate because the code concerns the main drive lithium-ion battery CMU identification system. Whether service is immediately required is not yet established by verified evidence.
Confidence95%

Quick answer

P1AA3 is a Mitsubishi i-MiEV diagnostic trouble code for a CMU ID change affecting CMU09. Verified evidence identifies it as part of the main drive lithium-ion battery diagnostic information.

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 P1AA3 mean?

P1AA3 is a Mitsubishi i-MiEV diagnostic trouble code for a CMU ID change affecting CMU09. Verified evidence identifies it as part of the main drive lithium-ion battery diagnostic information.

2. Technical explanation

The verified Mitsubishi service-bulletin evidence describes P1AA3 as “CMU ID change (CMU09).” CMU refers to a cell monitoring unit within the main drive lithium-ion battery system. The documented trouble judgment conditions include CMUs being numbered for identification and the absence of either listed reception-error DTC condition, including U1925 (CMU ID numbering reception error). Further diagnostic interpretation is not yet established by verified evidence.

3. What system is affected?

Main drive lithium-ion battery / CMU identification system.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

Not yet established by verified evidence.

6. Possible causes

  • A CMU ID change involving CMU09 is established by verified evidence. The underlying reason for that change 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

  • Do not attempt high-voltage battery or CMU repair procedures yourself.
  • Have the DTC evaluated by a qualified Mitsubishi EV service facility using applicable Mitsubishi diagnostic procedures.

10. Step-by-step troubleshooting

  1. Confirm the stored DTC is P1AA3.
  2. Review related CMU identification and reception-error diagnostic information with appropriate manufacturer diagnostic equipment.
  3. Further step-by-step troubleshooting is not yet established by verified evidence.

11. When to contact service

Professional evaluation is appropriate because the code concerns the main drive lithium-ion battery CMU identification system. Whether service is immediately required is not yet established by verified evidence.

12. What the service center may check

  • Check diagnostic information for P1AA3: CMU ID change (CMU09).
  • Check whether U1925, described as a CMU ID numbering reception error, is stored, as referenced in the documented trouble judgment conditions.
  • Follow the applicable Mitsubishi main drive lithium-ion battery diagnostic procedure.

13. Possible repair or resolution

  • Not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Mitsubishi TSB-19-54-004, published March 13, 2019, includes P1AA3 in main drive lithium-ion battery diagnostic information.
  • Mitsubishi TSB-19-54-003, published March 13, 2019, includes P1AA3 in main drive lithium-ion battery diagnostic information.

16. Recall information

No recall relationship is established by verified evidence.

17. Official manufacturer information

Verified NHTSA-hosted Mitsubishi manufacturer communications: TSB-19-54-004 (https://static.nhtsa.gov/odi/tsbs/2019/MC-10158409-9999.pdf) and TSB-19-54-003 (https://static.nhtsa.gov/odi/tsbs/2019/MC-10158408-9999.pdf). Verified applicability: 2012 and 2014 Mitsubishi i-MiEV models in the United States.

19. Frequently asked questions

What does P1AA3 mean?

Verified evidence defines P1AA3 as “CMU ID change (CMU09).”

Which vehicles are verified as applicable?

Verified applicability includes U.S.-market 2012 and 2014 Mitsubishi i-MiEV vehicles.

Is P1AA3 safe to drive or charge with?

Not yet established by verified evidence.

Is P1AA3 a recall?

No recall information was supplied in the verified evidence.

20. Sources & verification

Verified
Mitsubishi P1AA3: CMU ID change (CMU09), P1AA4: CMU ID change (CMU10),… | EV Diagnostics