When my MECS pump failed I was level road cruising at 55mph, and the system overheated within maybe five miles.

Question is, where is the MECS heat coming from when I'm cruising ICE only? The EV components would seem to be mostly idle under that condition, so what's the heat source that caused the overheating?

 

The EV components are in constant use at any speed, either charging or discharging. They are never disconnected. If you have the model with built in GPS, the display screen will show the power transfer.

 

The EV components are in constant use at any speed, either charging or discharging. They are never disconnected. If you have the model with built in GPS, the display screen will show the power transfer.

EDIT: My 2008 was built in the first part of the model year; I suspect I have the old design MCES. Hopefully if it fails it will be while my extended warranty is active...

 

Steve, the pump is right by the oil filter. You can just scoot under the front of the FEH and have a look at the pump. The newer pump is much smaller than the old model. One of the threads here has a link to a side by side picture of the two pumps.

 

Thanks, I had already read that valuable post. I don't have the time just now, and I don't think I would replace the part proactively anyway (which means there is little point in knowing).