MikeFusionH

134a gauges still work on these cars and using an ambient temp chart you can get accurate indications of what needs to be done to properly charge and maintain these systems. the only thing you need to be careful of is overcharging (like any 134a system) but if you vacuum the system you need new gauges that are pristine so that you do not contaminate the compressor with the wrong oil (NOT PAG) which causes a dangerous condition that makes the compressor electrically live and dangerous due to the high voltage requirements.

not sure i understand your question but if your high side pressure is 300 you need to read low side pressure too-300 is way too high, low should be around 35 and high around 200. my 2010 hybrid, which owned since 2017 recently began to not cool and adding a can of 134a brought pressures back up to proper pressures and vent temps now stay consistently around 35-40F. it sounds like your electronic compressor is straining at 300 psi so it shuts down to protect itself.

sounds like the throttle body might be having issues, i had similar symptoms years ago on my '10 hybrid, wrench light and no codes, ended up replacing the throttle body because the electronics in the TB crack and dry out over years of use and create those issues. it is a really easy fix, and 3 years ago the cost was only about $75 including the gasket, no telling how much it is now though thanks to our government printing money as it needs it so that all our money is worth less.

you just need a decent scanner that does ABS codes.

i thought i answered this earlier, yes it is the throttle body it is very common and the TB on the fusion hybrid is the only car with the 2.5 that they did not recall it-and it is the exact same TB as what is on the other models. it is not very expensive, I did mine in about 10 minutes maybe a year or two ago, i think it was maybe $60 total.

$1000? really? that is a joke.

i have a 2010, bought it used in 2017 with about 85,000 now has 130.000 and no issues at all. shortly after buying it I replaced the OEM battery with the 96R, modification to make it fit was not all that difficult since the tray is plastic. the 97 R is 590 CCA as opposed to the oem which was 390 CCA. I did use a large zip tie to secure it since the oem holder would not work but i don't remember exactly why. i know it is not a 'starting' battery, but the 200 extra CCA's just sounds better to me. MORE POWER!!!

it is the throttle body i can almost guarantee it-look online there were so many issues with these that Ford did a recall and did not include the fusion HYBRID in spite of the fact it is the identical part number. it will cost about 75 bucks total and is very easy to replace, i just did mine at 118,000 exact same symptoms. the electronic part of the TB that is plastic and black is the culprit and years of heat soak cause it to go bad but you cannot buy just that part, you have to get the entire TB.i bought both the throttle body and gasket on amazon for a total of about $72 and it took all of about 15 minutes to replace it. no more problems, well-known issue.

don't know why this post lists me as 'MikeFusionH' but i am the original OP (mmtphoto) so this is weird-anyway thought I'd do a follow up- I drove this car with the cleaned O2 sensor for about 2400 miles, and had to clear a CEL light probably 3 times so I got a new sensor and no more issues. it seemed to run smoother and gas mileage was marginally improved. shortly after replacing it, my wife had an issue on the interstate where the car lost power and the 'wrench' light came on indicating limp mode. she called and i told her to get to the side of the road and shut it down and restart it. she drove it home and we left it sitting while i could scan it to see what was up-no codes, so on investigating i found that the throttle body was the probable cause of this problem. this 2010 has about 118,000 miles and i always periodically clean the throttle body, but the consensus was that the oem throttle body was defective. i found one on line for about $60 and a gasket for $12, installed it (15 minutes total if that). I disconnected the neg cable and attached a jumper from the loose ground to the pos cable to power down the system, started it up and let it idle for 10 minutes with the ac running. then i drove it gently for another 20 minutes. finally i did a HVB balance using my scanner. the removed throttle body was clean on top but the bottom of the throttle plate was nasty. these changes (new O2 sensor, throttle body, reset computer and rebalance of the HVB) now gets gas mileage up to close to 40 mpg as opposed to the 35 mpg it was getting. So other than oil changes, these repairs and doing the rear brakes at 94,000 miles this car is still stock and gets 40 mpg, is full sized, and looks/runs great. the ni-mh batteries after balance were within .01 volt and it still has great performance in HV and ICE modes. Love this car and hope to get more years out of it plus I might consider, when the time comes, getting a new battery pack just to drive it more years. Ford hit a home run with these cars IMO.