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Mitsubishi P1AA5

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

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceService is recommended because P1AA5 concerns identification information in the main drive lithium-ion battery CMU system. The urgency and whether the vehicle must be towed are not established by verified evidence.
Confidence95%

Quick answer

P1AA5 is a Mitsubishi main drive lithium-ion battery diagnostic trouble code for “CMU ID change (CMU11).” Verified evidence states the code is judged when CMUs are being numbered for identification, U1925 (CMU ID numbering reception error) is not stored, and identification-number information is modified.

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 P1AA5 mean?

P1AA5 is a Mitsubishi main drive lithium-ion battery diagnostic trouble code for “CMU ID change (CMU11).” Verified evidence states the code is judged when CMUs are being numbered for identification, U1925 (CMU ID numbering reception error) is not stored, and identification-number information is modified.

2. Technical explanation

CMU refers to a battery monitoring/control unit within the main drive lithium-ion battery system. For P1AA5, the referenced CMU is CMU11. The supplied official Mitsubishi technical-service-bulletin evidence identifies P1AA5 as an ID-change code, not as a general battery-cell failure code. The exact fail-safe action, diagnostic procedure, root cause, and repair procedure are not established by the supplied verified evidence.

3. What system is affected?

Main drive lithium-ion battery; CMU identification/numbering information, specifically CMU11.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • A stored P1AA5 diagnostic trouble code may be present.
  • Additional driver-visible symptoms are not yet established by verified evidence.

6. Possible causes

  • Verified judgment criterion: information pertaining to the identification number is modified.
  • The underlying reason that the identification-number information was modified 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

  • Arrange diagnosis by a Mitsubishi-qualified EV service facility.
  • Do not attempt high-voltage battery disassembly or CMU service yourself.
  • Record any warning messages and the conditions under which the code was read, if available.

10. Step-by-step troubleshooting

  1. Have a qualified technician retrieve and document all stored diagnostic trouble codes.
  2. A qualified technician should evaluate P1AA5 in the context of CMU identification/numbering information and the presence or absence of U1925, consistent with the verified judgment conditions.
  3. Specific test steps are not provided by the supplied verified evidence.

11. When to contact service

Service is recommended because P1AA5 concerns identification information in the main drive lithium-ion battery CMU system. The urgency and whether the vehicle must be towed are not established by verified evidence.

12. What the service center may check

  • Confirm P1AA5 is stored.
  • Check whether U1925, described in the source as “CMU ID numbering reception error,” is stored.
  • Assess CMU identification-number information for CMU11 using Mitsubishi-approved diagnostic procedures. Further service checks are not established by verified evidence.

13. Possible repair or resolution

  • No specific repair, replacement, programming procedure, or resolution is established by the supplied verified evidence.
  • Do not infer that the battery, CMU11, or another component requires replacement solely from P1AA5.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Mitsubishi TSB-19-54-004, published March 13, 2019; NHTSA manufacturer communication 10158409. It identifies P1AA5 as “CMU ID change (CMU11).”
  • Mitsubishi TSB-19-54-003, published March 13, 2019; NHTSA manufacturer communication 10158408. It identifies P1AA5 as “CMU ID change (CMU11).”

16. Recall information

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

17. Official manufacturer information

Verified official sources: 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), both published March 13, 2019. Supplied applicability data identifies U.S.-market 2012 and 2014 Mitsubishi i-MiEV vehicles.

19. Frequently asked questions

What does P1AA5 mean on a Mitsubishi i-MiEV?

It means “CMU ID change (CMU11)” in the main drive lithium-ion battery diagnostic information.

What condition sets P1AA5?

The verified evidence says the check occurs when CMUs are numbered for identification, U1925 is not stored, and information pertaining to the identification number is modified.

Is P1AA5 confirmed for every Mitsubishi i-MiEV year?

No. The supplied applicability evidence identifies U.S.-market 2012 and 2014 Mitsubishi i-MiEV vehicles only.

Can I continue driving or charging with P1AA5?

Not yet established by verified evidence.

20. Sources & verification

Verified
Mitsubishi P1AA5: CMU ID change (CMU11), P1AA6: CMU ID change (CMU12),… | EV Diagnostics