Mitsubishi P1A8F
CMU02 balancer abnormal, P1A90: CMU03 balancer abnormal, P1A91: CMU04 balancer abnormal, P1A92: CMU05 balancer abnormal, P1A93: CMU06 balancer abnormal, P1A94: CMU07 balancer abnor
Quick answer
P1A8F is a Mitsubishi diagnostic trouble code for “CMU02 balancer abnormal.” Verified applicability is limited to U.S.-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 P1A8F mean?
P1A8F is a Mitsubishi diagnostic trouble code for “CMU02 balancer abnormal.” Verified applicability is limited to U.S.-market 2012 and 2014 Mitsubishi i-MiEV vehicles.
2. Technical explanation
The supplied official Mitsubishi service-bulletin evidence groups P1A8F with battery Cell Monitoring Unit (CMU) balancer-abnormal codes. P1A8F specifically identifies CMU02. The bulletin’s diagnostic path includes checking A/D conversion results for temperature sensors 1–6; if that check is not normal, it directs replacement of the Main Drive Lithium-ion Battery. If that check is normal, it directs a scan-tool DTC check; if the DTC is stored, it directs replacement of the BMU. These are manufacturer service procedures and should be performed by qualified EV service personnel.
3. What system is affected?
Main Drive Lithium-ion Battery monitoring/balancing system, including CMU02 and the BMU.
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 CMU02 balancer abnormal condition is established by the code definition.
- The official diagnostic procedure evaluates A/D conversion results for temperature sensors 1–6 and whether the DTC remains stored. A specific underlying component-level cause is not yet established by the supplied 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 qualified Mitsubishi EV service provider.
- Do not attempt high-voltage battery, CMU, balancing, or BMU repairs yourself.
10. Step-by-step troubleshooting
- A qualified technician can follow the official procedure using scan tool MB991958.
- The procedure checks A/D conversion results for temperature sensors 1–6.
- If the A/D conversion check is not normal, the bulletin directs replacement of the Main Drive Lithium-ion Battery.
- If the A/D conversion check is normal, the procedure checks whether the diagnostic trouble code is stored using scan tool MB991958.
- If the DTC is stored at that step, 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 manufacturer procedure calls for diagnostic testing and may direct Main Drive Lithium-ion Battery or BMU replacement. Safe-to-drive and safe-to-charge status are not established by the supplied evidence.
12. What the service center may check
- Perform the official A/D conversion check for temperature sensors 1–6.
- Use scan tool MB991958 to determine whether the DTC is stored after the A/D conversion check.
- Follow the applicable official decision path based on those results.
13. Possible repair or resolution
- If the temperature-sensor A/D conversion check is not normal, replace the Main Drive Lithium-ion Battery as directed by the official bulletin.
- If that check is normal and the DTC is stored, replace the BMU as directed by the official bulletin.
- If that check is normal and the DTC is not stored, the official bulletin states the check is complete.
14. Affected vehicles
- Mitsubishi i-MiEV · 2012 · US
- Mitsubishi i-MiEV · 2014 · US
15. Related TSBs / service bulletins
- TSB-19-54-004, published March 13, 2019: official Mitsubishi diagnostic information for P1A8F and related CMU balancer-abnormal codes. NHTSA manufacturer communication MC-10158409: https://static.nhtsa.gov/odi/tsbs/2019/MC-10158409-9999.pdf
- TSB-19-54-003, published March 13, 2019: official Mitsubishi diagnostic information for P1A8F and related CMU balancer-abnormal codes. NHTSA manufacturer communication MC-10158408: https://static.nhtsa.gov/odi/tsbs/2019/MC-10158408-9999.pdf
16. Recall information
No recall relationship is established by verified evidence.
17. Official manufacturer information
Verified official evidence: Mitsubishi TSB-19-54-004 and TSB-19-54-003, published through NHTSA on March 13, 2019. Verified vehicle applicability: 2012 and 2014 Mitsubishi i-MiEV, U.S. market. No recall information is established by the supplied evidence.
19. Frequently asked questions
What does P1A8F mean?
It means “CMU02 balancer abnormal.”
Which vehicles are verified as applicable?
U.S.-market 2012 and 2014 Mitsubishi i-MiEV vehicles.
Can I drive or charge with P1A8F?
Not yet established by verified evidence.
What does the manufacturer diagnostic procedure require?
It requires an A/D conversion check for temperature sensors 1–6 and, when that check is normal, a scan-tool check for whether the DTC is stored. The documented results may direct Main Drive Lithium-ion Battery replacement or BMU replacement.