Mitsubishi Outlander PHEV (GG) Common Problems & Reliability
The UK's best-selling plug-in hybrid for many years. It offers a practical family SUV experience with significant tax benefits for business users.
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Detailed fault breakdown, symptoms, and estimated repair bills by production year.
Most Common Mitsubishi Outlander PHEV (GG) Faults & Repair Costs
Battery Degradation & "BMU Reset" Masking
The traction battery naturally loses capacity over time. A major concern is the "BMU Reset" where a technician or seller resets the Battery Management Unit, forcing it to report 100% health (State of Health). This "masks" the actual degradation until the car relearns the true capacity over several weeks.
Suddenly dropping range after a few weeks of ownership, Inconsistent EV range, Petrol engine starting even when battery shows charge
- Use "PHEV Watchdog" and an OBDII dongle to check actual State of Health (SoH)
- Check for a suspiciously high health percentage on high-mileage cars
- Ask for a history of any BMU resets
Electric Heater Failure
The electric water heater (used when the engine is off) frequently fails. A small inline gauze filter can also block, preventing circulation.
No cabin heat when driving in EV mode, Heat only available when petrol engine is running
- Test the heater while the car is in EV mode and parked
AC Compressor Failure (Wrong Oil)
The electric compressor requires specialized POE oil. Using standard PAG oil during a regas will destroy the internal motor.
AC not cooling, Loud grinding noise when AC is on, EV system fault light
- Verify that any AC service used POE oil specifically
- Check AC operation in both EV and Petrol modes
Rear Differential Mount Thud
The rubber in the rear differential center mount perishes, leading to a "thud" or "clonk" when pulling away.
Thud from the rear when moving from a standstill, Clunk when releasing the brake
- Inspect the rear diff mount bushing for cracks or play
Buying a used Mitsubishi Outlander PHEV (GG)? Always check for hidden finance and write-off history.
Mechanical problems are only half the battle. Over 1 in 3 UK used cars checked have unpaid finance or accident write-off records that could cause you to lose the car or thousands in value.