07 FEH, 81K miles. approximately 75mph, AC on. Had an intermittent wrench light and " service soon message for several months. This week driving down in the interstate about 40 miles from home the gas engine quit. Wouldn't restart right away. Got towed. Engine restarted later. Took it to the shop. Two codes, one for the battery door actuator ( like gave the wrench light) , and one for the MECS. I'll order the MECS part from Nevada, and install myself. The dealer did a BCM reflash, and had him do the actuator door motor. Total cost for the Code scan, reflash and actuator door $500.00 Question. I have a scan gage but no MeT to monitor the temp.. was this something added on later. Does someone have the details? Thanks.

 

IIRC, there is no specific code for the MCES pump failure. Just a combination of diagnostic traits....overheating code, visible fluctuations in the coolant flow with the cap off, noises from the old pump, etc. Are you looking for a specific temperature sensor to tap into? The cylinder head temp (CHT) is the one I believe is actually measured.... I believe some temperatures that the PCM uses are inferred (estimated) from that reading.

 

I called scan gauge. They have updated xgauges that include a temp for the MECS. Thanks for replying.

 

Just wanted to add my 2¢ on the MECS pump issue:

If you hear the noise others described here and you do mostly local driving, wait for it to fail. If you hear noise and you have a big road trip planned - replace it.

My 08FEH had been making a noticeable noise from the front end around the MECS pump for months. I thought maybe I was just noticing it more since I'd been driving without my stereo on or perhaps it was just something else resonating. I even asked the dealership about it but they said it was fine and just replaced the battery air filter.

Six weeks ago, I moved from MD to TX and thought about replacing it, but opted for new tires since I was still on 3 OEMs with 80K on them. One day into my road trip in South Carolina I got the pull over safely warning. It was the MECS. Luckily I found a dealer that had the part so I could get back on the road and beat the movers to TX, but I could have done without the $$$ and aggravation.

-t,

 

I've got that growling on an '06 FEH with 126,000 miles. Based on what I've read in this thread, the MECS pump might die tomorrow or make it another year. I think I'll just replace it before I end up stuck on a mountain pass in the winter...

If any of the previous posters who lived with the growl, what was your outcome?

 

IIRC, my MECS pump failed around 34k miles, and it last eight months after becoming noisy enough for me to notice it.