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Mitsubishi P1AC2

ion batt ery is charged. Judgment Criterion  For more than 5 seconds, the PWM output signal of the main drive lithium-ion ba ttery fan is 10 percent (while the fan is being driven

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceMitsubishi EV-qualified service is appropriate because the verified repair direction concerns the main drive lithium-ion battery cooling fan.
Confidence95%

Quick answer

For a 2016 Mitsubishi i-MiEV (US), DTC P1AC2 is identified in Mitsubishi service information as “Battery Cooling Fan (SHT to BAT).” The cited TSB directs technicians to confirm the DTC with scan tool MB991958; if it is set, replace the main drive lithium-ion battery cooling fan.

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 P1AC2 mean?

For a 2016 Mitsubishi i-MiEV (US), DTC P1AC2 is identified in Mitsubishi service information as “Battery Cooling Fan (SHT to BAT).” The cited TSB directs technicians to confirm the DTC with scan tool MB991958; if it is set, replace the main drive lithium-ion battery cooling fan.

2. Technical explanation

Verified Mitsubishi/NHTSA evidence states that P1AC2 is evaluated when the electric motor switch is ON or while the main drive lithium-ion battery is being charged. The stated judgment criterion is present for more than 5 seconds while the fan is being driven, involving a 10% PWM output signal and the fan rotational-output condition. The supplied evidence does not fully reproduce the latter condition, so further technical interpretation is not yet established by verified evidence.

3. What system is affected?

Main drive lithium-ion battery cooling fan.

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 P1AC2 fault is identified by Mitsubishi as “Battery Cooling Fan (SHT to BAT).”
  • The verified TSB instructs replacement of the main drive lithium-ion battery cooling fan when scan-tool confirmation shows P1AC2 is set.
  • The TSB also allows for an intermittent malfunction when the DTC cannot be confirmed during its diagnostic procedure.

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 diagnosed using the Mitsubishi-specified scan tool procedure.
  • Do not attempt high-voltage battery or cooling-fan repair procedures without qualified EV service training.

10. Step-by-step troubleshooting

  1. Use scan tool MB991958 to confirm whether P1AC2 is set, as directed by Mitsubishi.
  2. If P1AC2 is set, the TSB directs replacement of the cooling fan in the main drive lithium-ion battery, referring to service manual section P.54D-211.
  3. If the DTC is not set during the procedure, the TSB identifies the condition as an intermittent malfunction and refers technicians to the intermittent-malfunction diagnostic process in Group 00.

11. When to contact service

Mitsubishi EV-qualified service is appropriate because the verified repair direction concerns the main drive lithium-ion battery cooling fan.

12. What the service center may check

  • Confirm P1AC2 using scan tool MB991958.
  • Follow Mitsubishi service information for cooling-fan replacement when the DTC is confirmed.
  • If not confirmed, follow the Mitsubishi intermittent-malfunction diagnostic process.

13. Possible repair or resolution

  • When P1AC2 is confirmed, Mitsubishi TSB-19-54-005 directs replacement of the main drive lithium-ion battery cooling fan.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Mitsubishi TSB-19-54-005, published through NHTSA as Manufacturer Communication MC-10158410-9999 (2019-03-13). It covers DTC P1AC2 Battery Cooling Fan (SHT to BAT) and directs confirmation with scan tool MB991958 followed by cooling-fan replacement if the DTC is set.

16. Recall information

No recall relationship is established by verified evidence.

17. Official manufacturer information

Official source: NHTSA Manufacturer Communication PDF 10158410, Mitsubishi TSB-19-54-005: https://static.nhtsa.gov/odi/tsbs/2019/MC-10158410-9999.pdf

19. Frequently asked questions

What does P1AC2 mean on a 2016 Mitsubishi i-MiEV?

The verified Mitsubishi TSB identifies P1AC2 as “Battery Cooling Fan (SHT to BAT).”

What repair does Mitsubishi specify if P1AC2 is confirmed?

The TSB directs replacement of the cooling fan in the main drive lithium-ion battery.

Can P1AC2 occur while charging?

Yes. The verified check conditions include while the main drive lithium-ion battery is charged.

Is it safe to drive or charge with P1AC2?

Not yet established by verified evidence.

20. Sources & verification

Verified
Mitsubishi P1AC2: ion batt ery is charged. Judgment Criterion  For… | EV Diagnostics