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Mitsubishi P1A8E

CMU01 balancer abnormal, P1A8F: CMU02 balancer abnormal, P1A90: CMU03 balancer abnormal, P1A91: CMU04 balancer abnormal, P1A92: CMU05 balancer abnormal, P1A93: CMU06 balancer abnor

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceService is appropriate because the verified procedure involves Main Drive Lithium-ion Battery and BMU diagnostic and replacement decisions. The evidence does not establish urgency, driving restrictions, or charging restrictions.
Confidence95%

Quick answer

P1A8E is identified in Mitsubishi service bulletins as “CMU01 balancer abnormal.” Verified applicability is limited to US-market 2012 and 2014 Mitsubishi i-MiEV vehicles.

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 P1A8E mean?

P1A8E is identified in Mitsubishi service bulletins as “CMU01 balancer abnormal.” Verified applicability is limited to US-market 2012 and 2014 Mitsubishi i-MiEV vehicles.

2. Technical explanation

The supplied official Mitsubishi/NHTSA bulletin evidence groups P1A8E with battery Cell Monitoring Unit (CMU) balancer fault codes. P1A8E specifically denotes an abnormal condition for the CMU01 balancer. The bulletin diagnostic path calls for checking specified reference-voltage and temperature-sensor A/D-conversion items, then checking whether the DTC remains stored with scan tool MB991958. The evidence does not establish an owner-performed diagnosis or a component-level repair procedure.

3. What system is affected?

Main Drive Lithium-ion Battery monitoring/balancing system; specifically the CMU01 balancer and Battery Management Unit (BMU) diagnostic path.

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

  • The official bulletin identifies an abnormal CMU01 balancer condition for P1A8E.
  • The supplied evidence does not establish a root cause beyond the diagnostic checks and replacement path specified in the bulletin.

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 qualified Mitsubishi EV service facility.
  • Do not attempt high-voltage battery, CMU, balancer, or BMU repairs yourself.
  • Record the stored DTC and any warning messages for the service provider.

10. Step-by-step troubleshooting

  1. A Mitsubishi service procedure cited in the supplied bulletins checks reference-voltage and temperature-sensor A/D-conversion items 68 through 73.
  2. If those check results are not normal, the bulletin directs replacement of the Main Drive Lithium-ion Battery.
  3. The procedure then checks whether the DTC is stored using scan tool MB991958.
  4. If the DTC remains stored, the bulletin directs replacement of the BMU; if it is not stored, the check is complete.

11. When to contact service

Service is appropriate because the verified procedure involves Main Drive Lithium-ion Battery and BMU diagnostic and replacement decisions. The evidence does not establish urgency, driving restrictions, or charging restrictions.

12. What the service center may check

  • Check the specified reference-voltage item.
  • Check A/D conversion for temperature sensors 1 through 6, identified as items 68 through 73 in the bulletin.
  • Use scan tool MB991958 to determine whether P1A8E remains stored after the preceding checks.

13. Possible repair or resolution

  • If the specified check result is not normal, the bulletin directs replacement of the Main Drive Lithium-ion Battery.
  • If the specified checks are normal and P1A8E is stored, the bulletin directs replacement of the BMU.
  • If the specified checks are normal and the DTC is not stored, the bulletin states that the check is complete.

14. Affected vehicles

15. Related TSBs / service bulletins

  • TSB-19-54-004, published March 13, 2019, is an official manufacturer communication available through NHTSA. Its supplied evidence includes P1A8E as “CMU01 balancer abnormal” and the associated diagnostic path.
  • TSB-19-54-003, published March 13, 2019, is an official manufacturer communication available through NHTSA. Its supplied evidence includes the same P1A8E definition and diagnostic path.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified sources: NHTSA manufacturer communications TSB-19-54-004 (MC-10158409) and TSB-19-54-003 (MC-10158408), both published March 13, 2019. Verified vehicle applicability supplied for this page: US-market Mitsubishi i-MiEV, model years 2012 and 2014.

19. Frequently asked questions

What does P1A8E mean on a Mitsubishi i-MiEV?

The verified bulletin definition is “CMU01 balancer abnormal.”

Does P1A8E mean the Main Drive Lithium-ion Battery must be replaced?

Not necessarily. The bulletin directs Main Drive Lithium-ion Battery replacement if its specified reference-voltage and temperature-sensor A/D-conversion checks are not normal. If those checks are normal but the DTC is stored, it directs BMU replacement.

Can I drive or charge with P1A8E?

Not yet established by verified evidence.

Which vehicles are verified as applicable?

The supplied applicability evidence identifies US-market 2012 and 2014 Mitsubishi i-MiEV vehicles.

20. Sources & verification

Verified
Mitsubishi P1A8E: CMU01 balancer abnormal, P1A8F: CMU02 balancer… | EV Diagnostics