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Mitsubishi P1A4B

/C0068Print (and save) an “All DTC List.” /C0068Open a Techline case, and attach the DTC List to the Techline case. Click on the paper clip icon to attach files. /C0068Call TechLin

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact a Mitsubishi-qualified service facility. Mitsubishi bulletin instructions specifically require a Techline case and TechLine contact for P1A4B in the cited battery-cell-voltage diagnostic context.
Confidence95%

Quick answer

For verified U.S. Mitsubishi i-MiEV applications, P1A4B is treated in Mitsubishi service information as a main drive lithium-ion battery/cell-voltage-related DTC. Mitsubishi directs technicians to print and save an All DTC List, open a Techline case, attach the list, call TechLine, and skip Cell Voltage Smoothing.

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 P1A4B mean?

For verified U.S. Mitsubishi i-MiEV applications, P1A4B is treated in Mitsubishi service information as a main drive lithium-ion battery/cell-voltage-related DTC. Mitsubishi directs technicians to print and save an All DTC List, open a Techline case, attach the list, call TechLine, and skip Cell Voltage Smoothing.

2. Technical explanation

Verified Mitsubishi/NHTSA bulletin evidence states that P1A4B may be set in the BMU (Battery Management Unit). One Mitsubishi bulletin identifies the probable cause as a failed module—battery cell and CMU—in the main drive lithium-ion battery. The supplied evidence does not establish a consumer-facing expanded definition beyond this service context.

3. What system is affected?

Main drive lithium-ion battery and BMU; battery cell/CMU module service context.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • P1A4B may be stored in the BMU.
  • No driver-visible symptoms are established by the supplied verified evidence.

6. Possible causes

  • A failed module, consisting of a battery cell and CMU, in the main drive lithium-ion battery is identified as the probable cause in Mitsubishi bulletin evidence.
  • Not yet established by verified evidence whether other causes apply.

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

  • Have the vehicle evaluated by a Mitsubishi-qualified service facility.
  • Provide the stored DTC information to the service facility.
  • Do not attempt high-voltage battery or battery-module repair yourself.

10. Step-by-step troubleshooting

  1. Mitsubishi service information directs use of scan tool MB991958 to confirm whether P1A4B is set in the BMU.
  2. The bulletin directs technicians to print and save an All DTC List.
  3. The bulletin directs technicians to open a Techline case, attach the DTC List, and call TechLine.
  4. For P1A4B or other battery-cell-voltage-related DTCs, Mitsubishi directs technicians to skip Cell Voltage Smoothing and proceed through the specified service process.
  5. Mitsubishi bulletin evidence includes a check of whether a main drive lithium-ion battery module was recently replaced; if so, it directs erasing the DTC and checking completion. This is a technician procedure.

11. When to contact service

Contact a Mitsubishi-qualified service facility. Mitsubishi bulletin instructions specifically require a Techline case and TechLine contact for P1A4B in the cited battery-cell-voltage diagnostic context.

12. What the service center may check

  • Confirm P1A4B in the BMU with scan tool MB991958.
  • Review all stored DTCs and preserve an All DTC List.
  • Determine whether a main drive lithium-ion battery module was recently replaced.
  • Review battery data-list items including minimum-voltage cell ID and battery total voltage, as referenced by the bulletin.
  • Follow Mitsubishi TechLine direction for the case.

13. Possible repair or resolution

  • If a main drive lithium-ion battery module was recently replaced, the cited Mitsubishi procedure directs erasing the DTC and confirming the check is complete.
  • For a failed battery cell/CMU module, the supplied evidence identifies the module as the probable fault area but does not establish a specific repair outcome or replacement authorization.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Mitsubishi TSB-19-54-005, published March 13, 2019; NHTSA manufacturer communication MC-10158410.
  • Mitsubishi TSB1754003, published July 26, 2017; NHTSA manufacturer communications MC-10116253 and MC-10115257.

16. Recall information

  • No recall information is established by the supplied verified evidence.

17. Official manufacturer information

Verified sources are NHTSA-hosted Mitsubishi manufacturer communications: https://static.nhtsa.gov/odi/tsbs/2019/MC-10158410-9999.pdf and https://static.nhtsa.gov/odi/tsbs/2017/MC-10116253-9999.pdf.

19. Frequently asked questions

Which vehicles are supported by the supplied evidence?

U.S. Mitsubishi i-MiEV model years 2012–2013 and 2016.

Does P1A4B mean Cell Voltage Smoothing should be performed?

No. The cited Mitsubishi bulletin directs technicians to skip Cell Voltage Smoothing when P1A4B or other battery-cell-voltage-related DTCs are found and to proceed through the specified Techline process.

Can I continue driving or charging?

Not yet established by verified evidence.

20. Sources & verification

Verified
Mitsubishi P1A4B: /C0068Print (and save) an “All DTC List.” /C0068Open… | EV Diagnostics