The 2012 i-MiEV is Mitsubishi's quirky city EV built on a Kei-car platform. Main issues center around the aging lithium-ion battery pack, vacuum brake booster failures, and a surprisingly fragile single-speed reduction gear that doubles as the front differential.
Lithium-Ion Battery Pack Degradation
Common · high severityTypical onset: 60,000-100,000 mi or 8-10 years
Symptoms: Range drops below 40 miles on full charge (original ~62 mi EPA), Battery capacity bars disappear on dash display, Increased charging times, Cell imbalance codes (P1A15, P1A1A)
Fix: Battery pack replacement is the only real fix. Used packs from salvage run $3,000-5,000, new OEM discontinued but aftermarket cells available. Requires lift, high-voltage safety procedures, 6-8 hours labor including BMS relearn
Estimated cost: $5,000-8,000
Electric Vacuum Pump / Brake Booster Failure
Common · high severityTypical onset: 50,000-90,000 mi
Symptoms: Hard brake pedal, increased stopping distance, Vacuum pump runs continuously or not at all, Brake warning light with code C1552, Whining or buzzing noise from under hood
Fix: Electric vacuum pump (since there's no engine) fails commonly. Pump replacement is 2-3 hours, booster itself another 3-4 if the diaphragm tears. Subject to recall but many units still fail post-fix. Pump alone is easier, booster requires brake line work
Estimated cost: $800-1,800
Front Reduction Gear / Differential Bearing Failure
Occasional · high severityTypical onset: 80,000-120,000 mi
Symptoms: Loud whining or grinding from front axle during acceleration, Metallic debris in gear oil, Vibration through steering wheel, Eventually: complete loss of drive
Fix: Single-speed reduction gear uses small bearings that wear prematurely, especially if fluid was never changed. Requires complete transaxle removal and rebuild. No reman units available—must source used or rebuild with aftermarket bearings. 8-10 hours labor, specialized EV knowledge required
Estimated cost: $2,500-4,500
12V Auxiliary Battery Failure
Common · medium severitySymptoms: Car won't enter READY mode even with full traction battery, Dash won't illuminate, door locks inoperative, P1A13 code (DC-DC converter communication fault), Clicking from under rear seat
Fix: Tiny 12V battery under rear seat powers computers and contactors. Fails every 3-5 years, often without warning. Unlike gas cars, you can't jump-start to limp home. Replacement is 0.5 hours, but must be specific absorbed glass mat (AGM) type. DC-DC converter can also fail (rare), which is $1,200 part plus 4 hours
Estimated cost: $250-400 (battery), $1,800-2,200 (DC-DC converter)
CHAdeMO Fast-Charge Port Degradation
Occasional · medium severityTypical onset: 70,000+ mi or heavy fast-charge use
Symptoms: CHAdeMO fast charging won't initiate or stops mid-charge, Pins in charge port corroded or burned, Error code on fast-charge station, Level 2 charging still works fine
Fix: CHAdeMO inlet wears from repeated plugging or moisture intrusion. Pins can arc and burn. Inlet replacement requires removing inner fender liner, 2-3 hours. Part availability is hit-or-miss, sometimes requires used unit from salvage
Estimated cost: $600-1,200
Inverter Coolant Pump Failure
Occasional · high severityTypical onset: 90,000-130,000 mi
Symptoms: Reduced power / limp mode during highway driving, P0AA6 (hybrid battery coolant pump performance), Inverter overheating warnings, Coolant pump doesn't run, audible when key is on
Fix: Electric motor and inverter share a coolant loop with electric pump. Pump impeller or motor fails, causes inverter overtemp and power limiting. Pump is under vehicle, 2-3 hours with coolant drain/refill. Must use specific ethylene glycol coolant, not standard antifreeze
Estimated cost: $700-1,200
Door Latch and Power Window Regulator Failures
Occasional · low severityTypical onset: 60,000-100,000 mi
Symptoms: Door won't latch securely, dash shows door ajar, Window drops into door or won't rise, Plastic window regulator clips break, Door handle feels loose or doesn't engage
Fix: Kei-car platform uses lightweight plastic latches and regulators that wear. Window regulator replacement is 2-3 hours per door with panel removal, latch is 1.5 hours. Parts availability is poor for some trim pieces, may need salvage yard sourcing
Estimated cost: $400-800 per door
Buy only if you need a cheap urban runabout under 30 miles/day and can wrench yourself—battery replacement and reduction gear rebuilds kill resale economics for most owners.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.