Mitsubishi P1AA8
Local CAN (for Main Drive Lithium-ion Battery) signal time-ou t b. U1082: Local CAN (for Main Drive Lithium-ion Battery) bus off Judgment Criterion The module temperature is less
Quick answer
P1AA8 is documented by Mitsubishi as a Local CAN signal timeout for the Main Drive Lithium-ion Battery. It is verified for US-market 2012, 2014, and 2016 Mitsubishi i-MiEV vehicles. A qualified Mitsubishi EV service facility should diagnose it.
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 P1AA8 mean?
P1AA8 is documented by Mitsubishi as a Local CAN signal timeout for the Main Drive Lithium-ion Battery. It is verified for US-market 2012, 2014, and 2016 Mitsubishi i-MiEV vehicles. A qualified Mitsubishi EV service facility should diagnose it.
2. Technical explanation
Official Mitsubishi service bulletin material identifies P1AA8 as “Local CAN (for Main Drive Lithium-ion Battery) signal time-out.” Related bulletin text also uses the wording “Bat-CAN signal time out.” The supplied evidence associates this code with Main Drive Lithium-ion Battery communication and battery-module diagnostic procedures. One documented criterion concerns battery-cell voltage differences greater than 0.05 V; another concerns module temperature below -30°C (-22°F), under the stated test conditions. The evidence also notes that a DTC may be set after a battery module replacement because the new cell state differs from the others, and that this specific post-replacement DTC does not necessarily indicate a malfunction.
3. What system is affected?
Main Drive Lithium-ion Battery local CAN/Bat-CAN communication and battery-module monitoring.
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
- Official bulletin material identifies the Main Drive Lithium-ion Battery module, including the battery cell, CMU, and module temperature sensor, in relevant diagnostic sections. The complete probable-cause text is not established by the supplied verified evidence.
- A battery-cell voltage difference greater than 0.05 V is a documented judgment criterion in supplied bulletin material.
- Module temperature below -30°C (-22°F) is a documented judgment criterion in supplied bulletin material.
- A DTC can be set following battery-module replacement because the new battery cell state differs from other cells; the bulletin states this post-replacement DTC does not indicate a malfunction.
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, temperature-sensor, or battery communication-system repairs yourself.
- Record whether the code appeared after battery-module replacement, as this circumstance is specifically addressed in the official bulletin material.
10. Step-by-step troubleshooting
- A service technician can confirm the stored DTC and evaluate it using the applicable Mitsubishi diagnostic procedure.
- The supplied bulletin material specifies test conditions that include waiting three seconds after the electric motor switch is turned ON or after Main Drive Lithium-ion Battery charging starts.
- One supplied procedure also specifies current below 1 A and battery total voltage above 350 V.
- The technician can evaluate the documented battery-cell voltage-difference criterion of more than 0.05 V.
- The technician can evaluate the documented module-temperature criterion of less than -30°C (-22°F), where applicable.
- If a battery module was replaced, the technician should account for the bulletin note that a resulting DTC can reflect differing cell state rather than a malfunction.
11. When to contact service
Service is recommended because the code concerns Main Drive Lithium-ion Battery communication and the supplied procedures involve battery diagnostic criteria. Urgency and whether the vehicle may be driven or charged are not yet established by verified evidence.
12. What the service center may check
- Retrieve and confirm P1AA8 and assess U1082, which is referenced in the same official diagnostic material as Main Drive Lithium-ion Battery local CAN/Bat-CAN bus-off.
- Apply the Mitsubishi diagnostic check conditions and judgment criteria in the applicable service information.
- Check battery-cell voltage differences against the documented greater-than-0.05 V criterion.
- Check module temperature against the documented less-than--30°C (-22°F) criterion where applicable.
- Determine whether a battery module was recently replaced and interpret any resulting DTC in accordance with the bulletin note.
13. Possible repair or resolution
- Not yet established by verified evidence. The supplied excerpts do not provide a complete verified repair procedure or final repair outcome.
- Where a module has been replaced, official bulletin text states that a DTC may be set because the new cell differs in state from the other cells and that this DTC does not indicate a malfunction.
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: includes P1AA8 Local CAN signal timeout and U1082 Local CAN bus-off in Main Drive Lithium-ion Battery diagnostic material; supplied excerpt documents a module-temperature criterion below -30°C (-22°F).
- Mitsubishi TSB-19-54-004, published March 13, 2019: includes P1AA8 and U1082 in Main Drive Lithium-ion Battery diagnostic material; supplied excerpt documents battery-cell voltage difference greater than 0.05 V and stated test conditions.
- Mitsubishi TSB-19-54-005, published March 13, 2019: uses P1AA8 Bat-CAN signal timeout and U1082 Bat-CAN bus-off wording; supplied excerpt documents battery-cell voltage difference greater than 0.05 V and the post-module-replacement DTC note.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified official sources: NHTSA-hosted Mitsubishi manufacturer communications TSB-19-54-003 (MC-10158408), TSB-19-54-004 (MC-10158409), and TSB-19-54-005 (MC-10158410), all published March 13, 2019.
19. Frequently asked questions
What does P1AA8 mean on a Mitsubishi i-MiEV?
It is identified in the supplied Mitsubishi bulletin material as a Local CAN signal timeout for the Main Drive Lithium-ion Battery. Another supplied bulletin excerpt calls it a Bat-CAN signal timeout.
Which vehicles are verified as applicable?
US-market Mitsubishi i-MiEV model years 2012, 2014, and 2016 are verified as applicable by the supplied database evidence.
Can a replacement battery module trigger this code?
Yes. Supplied official bulletin text states that a DTC may be set after module replacement because the new battery cell state differs from the other cells, and states that this DTC does not indicate a malfunction.
Can I drive or charge with P1AA8?
Not yet established by verified evidence.
Is P1AA8 associated with U1082?
Yes. The supplied Mitsubishi diagnostic excerpts list U1082 as Local CAN/Bat-CAN bus-off alongside P1AA8.