P0A7C criteria PCM parameter / wrench light?

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samster2.0
Posts: 4
Joined: Sat Oct 21, 2017 2:20 am
Vehicle: 2012 Fusion Hybrid; 2011 F150; 2007 F150

P0A7C criteria PCM parameter / wrench light?

Post by samster2.0 » Wed Oct 25, 2017 2:13 pm

I have a 2012 Fusion Hybrid. I live in TX and do a lot of high speed interstate driving, and so I get the P0A7C "Motor Electronics Over Temp" code and wrench light almost every day when driving at 75-80mph and when outside air temps are in the 80's or above (which is practically every month except Nov-Feb). No driveability concerns, just irritated that the light keeps coming on.

I used Forscan to scan the MECS_V PID to determine if the temperate of the MECS coolant was in fact going really high... turns out, its in the normal range even while the wrench light comes on and the code is set.
Supposedly the MECS coolant temp is not supposed to exceed 150F in "normal driving". I never even get close to that. In fact, the MECS temp values are higher when I'm NOT going at high speed, but they are higher when I'm going slower or stopped. I've already had the dealer replace the MECS pump for the newer style, and they don't know what's causing the wrench light. They said if I take it back in again, the only thing they can do is replace the entire engine/transaxle - at my cost, of course.

I've read that there are TSBs for earlier model fusions that address this issue.
Does anyone know what values they affect?
As far as the MECS pump goes, its either "on" or "off", and from documentation, its "on" anytime the key is on. Mine does not have any faults, and is always on like it should be.

I'm thinking there's some sort of a "temperature limit trigger" parameter in the PCM that needs to be adjusted higher, but not sure which - or even where to go to try and find out which parameter.

Any thoughts?
Thanks!

ThatOneDude
Posts: 162
Joined: Fri Jul 07, 2017 12:46 pm
Vehicle: 2012 Ford Expedition 5.4L 3V 4WD

Re: P0A7C criteria PCM parameter / wrench light?

Post by ThatOneDude » Wed Oct 25, 2017 11:26 pm

Sounds like the motor electronics module itself is over temp, and the MECS_V PID is reading the temp at the MECS pump. I would take that as an indication that the MECS pump is inoperable if they are separate units. Is there a separate PID for the temperature inside the motor electronics module?
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samster2.0
Posts: 4
Joined: Sat Oct 21, 2017 2:20 am
Vehicle: 2012 Fusion Hybrid; 2011 F150; 2007 F150

Re: P0A7C criteria PCM parameter / wrench light?

Post by samster2.0 » Thu Oct 26, 2017 12:23 am

I'll have to check the service information CD I have, but I believe that the MECS temp sensor is the only temp sensor in the MECS cooling circuit. It's already located directly in/on the electric motor, measuring the temp of the coolant at that point.

I'm thinking that the criteria is something to do with the relationship of the MECS_V temp sensor voltage related to the VREF voltage value, and maybe the problem is really with VREF?

Also of note, the coolant degas reservoir for the MECS doesn't even have a pressurized cap. When I stop the vehicle after driving it, its cool enough for me to open it and stick my finger in the coolant.

Poletoff
Posts: 4
Joined: Sun Dec 10, 2017 6:29 am
Vehicle: Ford Escape Hybrid 2,5 2010

Re: P0A7C criteria PCM parameter / wrench light?

Post by Poletoff » Tue Aug 07, 2018 7:04 am

Same trouble wit Ford Escape Hybrid 2010MY.
Ran on the highway. The temperature in the street is 91-92F. Inside the machine, the temperature is 73-74F. The speed is 75 miles per hour. There was a wrench and error P0A7S. After that several times I saw this error, but only on the road and only in hot weather. Ford has a TSB, but only for Ford Fusion, Lincoln MKZ and Mercury Milan. I do not know if this can help.
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wesiby
Posts: 1
Joined: Fri Aug 23, 2019 12:56 am
Vehicle: 2009 escape hev

Re: P0A7C criteria PCM parameter / wrench light?

Post by wesiby » Fri Aug 23, 2019 2:37 am

Has anyone figured this out. I have the exact problem. Its fine around town but when im on the highway its coming up with the wrench and mecs is above temp. Then back to normal after shutting off.

samster2.0
Posts: 4
Joined: Sat Oct 21, 2017 2:20 am
Vehicle: 2012 Fusion Hybrid; 2011 F150; 2007 F150

Re: P0A7C criteria PCM parameter / wrench light?

Post by samster2.0 » Wed Sep 04, 2019 9:03 pm

Ha! I was just googling for this code again - because I'm still having it - and it seems to have finally progressed into a red triangle and 'stop safely now'.
Although that only happened once and a restart of the car cleared it.

No, no one has figured it out yet that I'm aware of... :(

wr400f250
Posts: 1
Joined: Sat Oct 05, 2019 1:01 am
Vehicle: Fusion, 2.5L Hybrid, 2010

Re: P0A7C criteria PCM parameter / wrench light?

Post by wr400f250 » Sat Oct 05, 2019 7:25 pm

Just checking in, anybody find a solution to this yet? I have a '10 Fusion Hybrid at 182,000 miles. I drive a lot of highway, and this seems to happen after drives of about an hour or more. If I drive hard enough, I get Stop Safely Now and have to pull over to reset the car.

While resetting my battery age last night, I ventured into the codes and freezeframe data for the MECS (but this is all from my memory). Evidently, the coolant temp was within reason at the time of the code, around 90C. But, inverter temp was a whopping 150C. My theory is that the MECS pump is in fact failing or failed, and not providing enough flow to keep the inverter cool during highway drives. This makes sense because the ECVT relies on MG1 at all times, especially on the highway, to control engine output. A lack of coolant flow on the highway would allow anything near the radiator to stay reasonably cool, but the inverter would be piping hot as it is the furthest heat source from the radiator, and the biggest.

Long story short, I'll test and probably replace my MECS pump and see where it goes from there. I should have instant results, as I can reliably replicate the condition on any drive longer than an hour.

tlondon33
Posts: 1
Joined: Sat Dec 01, 2018 3:34 am
Vehicle: Escape F150 F250

Re: P0A7C criteria PCM parameter / wrench light?

Post by tlondon33 » Tue Oct 15, 2019 2:28 am

Im having the same issue on a Ford Escape. Have you bleed the trans axle cooling system or tried changing the transmission fluid?
Here a link you my use
https://www.atsg.us/atsg/blog/fordescapehybrid2/

Jrpavv
Posts: 2
Joined: Sat Aug 31, 2019 1:13 pm
Vehicle: Fusion Hybrid 2011

Re: P0A7C criteria PCM parameter / wrench light?

Post by Jrpavv » Mon Dec 16, 2019 11:19 pm

I've been having the same issue on my 2011 ever since I got it 3 years ago. Others on the Facebook Fusion Hybrid page are having the same issue.

Would be nice if Ford would issue a TSB after the 09/09/2010 build date, or if someone has a forscan fix for this.

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