Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Motor Electronics Cooling System (MECS)
The vehicle uses a pump driven cooling system, referred to as the Motor Electronics Cooling System (MECS) pump, to transfer heat generated by the ECVT and the Hybrid Electric Vehicle (HEV) DC/DC converter to the atmosphere. The system uses a coolant-to-air radiator design.
The MECS pump is an electric pump that runs any time the ignition is in the ON position. Unlike traditional cooling systems, there is no thermostat in the MECS , so coolant flow should be continuous and considerably less than traditional powertrain cooling systems.
The flow direction is from the DC/DC converter to the MECS pump through the ECVT , then through the MECS cooler from the LH to RH side of the vehicle back to the DC/DC converter.
The MECS cooling pump will make an audible noise if it is running and a slight vibration may be felt by touch.
The MECS cooling system has a coolant expansion tank mounted on top of the transaxle.
| Item | Part Number | Description |
|---|---|---|
| 1 | 8C045 | Motor Electronics Cooling System (MECS) coolant expansion tank |
| 2 | 8C351 | MECS coolant expansion tank outlet hose |
| 3 | 8B273 | Electronically Controlled Continuously Variable Transmission (eCVT)-to- MECS cooler hose |
| 4 | 8005 | MECS cooler |
| 5 | 8B274 | MECS cooler-to-DC/DC converter tube/hose assembly |
| 6 | 14B227 | DC/DC converter |
| 7 | 15179 | DC/DC converter-to- MECS pump hose |
| 8 | 8C419 | MECS pump |
| 9 | 8A567 | MECS pump-to- eCVT hose |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.