Mitsubishi P0AA1
ECU. Q: Is the DTC stored? YES : Carry out troubleshooting for the DTC. NO : Go to Step 4. STEP 4. Use scan tool MB991958 to confirm a DTC of other systems Check if the DTC is stor
Quick answer
For verified U.S. 2012, 2014, and 2016 Mitsubishi i-MiEV applicability, P0AA1 is addressed in Mitsubishi diagnostic procedures that call for clearing the stored DTC, cycling the electric motor switch, and checking whether it returns. If it returns, the procedure directs technicians to check the EV-ECU for other DTCs and then the A/C control unit for DTCs.
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 P0AA1 mean?
For verified U.S. 2012, 2014, and 2016 Mitsubishi i-MiEV applicability, P0AA1 is addressed in Mitsubishi diagnostic procedures that call for clearing the stored DTC, cycling the electric motor switch, and checking whether it returns. If it returns, the procedure directs technicians to check the EV-ECU for other DTCs and then the A/C control unit for DTCs.
2. Technical explanation
The supplied official Mitsubishi TSB evidence does not provide a component-level definition for P0AA1. It documents a diagnostic decision path: erase the stored DTC; set the electric motor switch from LOCK (OFF) to ON and temporarily to START; then check whether the DTC is stored/set again. If it is not stored/set, the diagnosis is complete. If it is stored/set, use scan tool MB991958 to check the EV-ECU for DTCs other than P0AA1, P1A17, or P1AF2. If another EV-ECU DTC is present, troubleshoot that DTC. If not, check the A/C control unit for a DTC; where one is present, troubleshoot it using Group 55 procedures.
3. What system is affected?
Not yet established by verified evidence. The documented procedure checks the EV-ECU and, if required, the A/C control unit.
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
- Not yet established by verified evidence. The supplied TSB excerpts instruct technicians to identify and troubleshoot other DTCs in the EV-ECU or A/C control unit when present, but do not establish a specific cause of P0AA1.
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 technician using the applicable factory diagnostic procedure.
- Record all stored DTCs before service, if a scan tool is available.
- Do not attempt high-voltage component testing or repair based on this information.
10. Step-by-step troubleshooting
- Using scan tool MB991958, erase the stored DTC.
- Cycle the electric motor switch from LOCK (OFF) to ON, then temporarily to START.
- Check whether the DTC is stored or set again.
- If P0AA1 does not return, the Mitsubishi procedure states that diagnosis is complete.
- If it returns, check the EV-ECU for DTCs other than P0AA1, P1A17, and P1AF2.
- If another EV-ECU DTC is present, carry out troubleshooting for that DTC.
- If no other specified EV-ECU DTC is present, check the A/C control unit for a DTC.
- If an A/C control unit DTC is present, carry out troubleshooting for that DTC, referring to Group 55 troubleshooting as cited by Mitsubishi.
11. When to contact service
Service is appropriate because the verified procedure requires scan tool MB991958 and directs diagnostic work based on DTC results. Whether service is immediately required is not yet established by verified evidence.
12. What the service center may check
- Confirm whether P0AA1 returns after clearing the DTC and cycling the electric motor switch.
- Check the EV-ECU for DTCs other than P0AA1, P1A17, and P1AF2.
- Check the A/C control unit for stored/set DTCs when no other specified EV-ECU DTC is found.
13. Possible repair or resolution
- Not yet established by verified evidence. The supplied documents provide a diagnostic routing procedure, not a confirmed repair.
14. Affected vehicles
- Mitsubishi i-MiEV · 2012 · US
- Mitsubishi i-MiEV · 2014 · US
- Mitsubishi i-MiEV · 2016 · US
15. Related TSBs / service bulletins
- Mitsubishi TSB-19-54-003, published March 13, 2019; NHTSA manufacturer communication MC-10158408.
- Mitsubishi TSB-19-54-004, published March 13, 2019; NHTSA manufacturer communication MC-10158409.
- Mitsubishi TSB-19-54-005, published March 13, 2019; NHTSA manufacturer communication MC-10158410.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Official NHTSA-hosted Mitsubishi communications: TSB-19-54-003 (https://static.nhtsa.gov/odi/tsbs/2019/MC-10158408-9999.pdf), TSB-19-54-004 (https://static.nhtsa.gov/odi/tsbs/2019/MC-10158409-9999.pdf), and TSB-19-54-005 (https://static.nhtsa.gov/odi/tsbs/2019/MC-10158410-9999.pdf). Verified applicability supplied: U.S. Mitsubishi i-MiEV model years 2012, 2014, and 2016.
19. Frequently asked questions
What does the verified Mitsubishi procedure say to do if P0AA1 does not return after clearing it and cycling the switch?
The procedure states that the diagnosis is complete.
What does the procedure check if P0AA1 returns?
It checks the EV-ECU for DTCs other than P0AA1, P1A17, and P1AF2. If none are found, it checks the A/C control unit for a DTC.
Does the supplied evidence identify the failed part for P0AA1?
No. A failed part is not yet established by verified evidence.