Nothing good, I'm afraid.

I have done a bunch more hot weather driving including triple digits this last weekend, continue to have the indicator light up, and continue to have no other symptoms;

- It's getting more sensitive; I have had a instances of the wrench lighting up in mid 70s (F) outside temp (where it used to require high 80s)
- Gen phase and coil temps are the hottest amongst what ForScan will tell me (as much as 112ºC) - coil temps still generally track about 20C above trans fluid when working
- MECS temps are low (high 30s to mid 40s C)
- Battery continues to behave, apparently (good voltages, temps below 40ºC w/ cabin-air-cooled pack in 2012) ...but OTOH it would be astonishing if a 13year/130k pack didn't have significantly degraded performance
- no SSN, no additional codes, no noticeable behavior change including regen braking before/during/after
- I do find it noticeably more likely to occur on an incline....I can cross a hot SFV at 75mph and have the wrench light up the second the road pitches up the Newhall pass (100% reliable there)
- light extinguishes when ignition is cycled even while everything's still hot

I hate to say it but I'm getting to the point of resorting to the ol' Car Talk® electrical-tape-over-the-idiot-light solution (what fault light? I don't see a fault light...) I have stopped making any kind of driving accommodation around this light and have yet to see any consequences.

Annoyingly, I need to take mine for likely PTU replacement (was rather hoping it wasn't that, but there is a persistent speed-related bearing noise and I have already replaced the ENTIRE front end including both knuckles and CVs).....so I am on the lookout for a hybrid-savvy indy mechanic and will certainly ask about this issue. I may also try to write Ford (pause for laughter) just to see if anyone might respond about what is TRIPPING that code, and if it is (as I suspect) a derived temperature from other electrical readings in the drive system, since there is no measurement pattern or threshold that I can detect.

< insert shrug here >

 

Have you found any negative impact on performance (e.g. fuel efficiency or acceleration)? It seems my Escape's fuel efficiency has gone down (sub 25 mpg).

 

Heh - I just came back to edit that I still see as-expected MPG (28+ combined, pretty decent for AT tires and taller H&R springs). No issues around town (regardless of outside temp) and even made a fairly recent climb to around 6000ft on a slower road (45mph speed limit but curvy enough to average a bit a below that) without any complaints. Seems to require freeway speed....which says "transmission fluid involvement" to me

 

Seems like my fuel efficiency is going down. I spoke with a mechanic who says he's encountered this issue before, mentioning something about air cooling not getting to the battery (he mentioned a fan), and that it'd cost me around $900 to fix. He also mentioned that it's good the car hasn't gone into limp mode but from others' stories on this thread, it doesn't sound like people have had problems with limp mode.

 

Are you able to keep tabs on battery temps en route? I still tend to think battery related issues are going to produce different codes than the one in this thread. The one battery overtemp episode I experienced resulted from a bag falling over and blocking the exhaust vent (I wish they'd run air across the whole pack and out the other side below the rear window, like where the intake is) during a long descent several years ago. I think I only noticed because the ICE was kept running, and subsequently that the battery was largely offline (no regen, traction current coming from MG1 only...hence engine run)....I believe the 'limp mode' would have produced a lot more lights on the dash and display, and it certainly wasn't SSN.

i've monitored battery temps (highest and lowest cell temps, via ForScan) on a dash-mounted tablet during the last bunch of climbs and have mostly seen 90s F....low 100s on very hot days. That doesn't seem overly concerning to me, so I haven't been troubleshooting the battery cooling system (just air in my 2012)

Also FWIW I'm pretty sure there's a battery fan PID

 

Hi EscapeFromLa!
I read your post always and like the way you think. This is an old thread i know but i wish i get a response from you. I bought 2010 ten days ago with around 90k with some idle hours. I drove back home 160 miles away. I got the infamous wrench light about 12-15 minutes in hwy driving (60ish mph). I kept driving and made it home and two nights after that i was driving in my area max speed was 40 ish (temp outside was around 50f) i got the message SSN 7 minutes in my drive. At was night time and the car was sitting in cooler weather. I pulled over restarted the engine and took it back home. I hooked up forscan and there was only one code which was the P1A0C:00-28. Since then i tried to avoid freeways and driving only around my local area for work related trips. I did drop in another used 12v battery which i bought a year ago and i know it is good, drained about a qt from transmission just to check the condition and fluid level which it was dark and planning on draining it so i just topped it off this time. After i did that i drove for two days after the SSN and nothing happened so far. The MECS pump looks like was replaced at some point by the previous owners and it is the small new design. The car has about 100k on it and it was sitting for about 4 months before it got listed. I tried to shine a light through the MECS reservoir and the fluid is green and i saw a very minor movement in compared to a 2011 belongs to a family member which has the original pump. The pump is always running when engine is on and i hear sloshing sound in the hose going to the dc-dc box. I hear inconsistent water sloshing and i try to squeeze the hose, i see more movement in the reservoir. Not sure now if it is the pump, some blockage in the system or something else? Can it be just the transmission fluid going bad? I would appreciate any insights as i got this car for work and trying to figure out before i go in longer higher speed trips. Today i drove around (was around 70f outside) and captured a video for the generators & MECS fluid temps. I would appreciate if you can view the short clip and tell me what do you think. Unfortunately i didn't check the temps when i got the wrench light driving on freeway and i can't trust driving it now. These readings where after 35 minutes driving around town no freeway.

 

Interesting - you're getting a slightly different code than me; P1A0C:00-28 appears to be related to the SSN warning you got (P1A0C looking like Hybrid Control Module and I think maybe forced engine stop...but I'm not seeing much specific to that 00-28 bit).
From what I can see, your temps actually look a little more coordinated than mine; my G_CLTEMP tends to track around 20C above TFT when working (freeway, hills). What jumps out to me is a fair bit of variation in your pack voltage. I don't see mine drop below 300 really, which might be a polling rate difference (I am monitoring from Android and I think it's slower to update, so it may see more short term average than instant).

Otherwise....it seems like you might actually have different things going on; I have never gotten a SSN and the issue I do get takes much warmer drivetrain condition that I'd guess you had in under 10 minutes of side street driving - that might suggest looking into the TSB for throttle body (I think that might have been for 09 - not sure if it'd span your model year). Guidance was to replace or clean if replacement was impossible. I think basically the butterfly valve was prone to sticking when gunked up, and the engine would hesitate on start (which happens a lot in a hybrid). Your earlier wrench light may or may not have been related to that...the P0A7C would normally stick for you to see via scan, but if you had changed the battery beforehand, it may have cleared it

And because I AM still getting my issue, here's what forscan read the last time it cropped up:


basically the same general circumstances, but it's requiring progressively lower exterior temps to trigger (I think it was low 70s that day)

 

When i got the SSN i didn't have my laptop on me so i scanned the next morning before clearing or replacing the battery and it was only the P1A0C:00-28. I know you have done some flushing to the coolant system and transmission fluid drain, did that improve the temps and at least push the limits higher? Whats concerning in my case is that the fluid movement in the reservoir is very slow compared to a 2011 belongs to a family member. Also the reservoir has green coolant not the gold motorcraft one. Did you notice a difference after flushing the coolant? Did you replace the pump or the MECS radiator?

 

No - neither coolant nor trans fluid seemed to make any appreciable difference for me. They don't make the OEM orange coolant anymore and the recommended replacement is yellow, though I honestly don't think it matters all that much. I was a bit surprised to see that the 2 coolant systems do intermix (I was told this by a Ford tech when I had them vacuum fill the MECS loop after replacing the pump, wanting to rule out air in the lines,....and sure enough, the distinct difference in the pinkish orange of the main coolant bottle and the yelllow in the MECS bottle averaged to a uniform color after a few months)

I don't have a ton of visible movement in the MECS coolant bottle either, and from what I can tell it's just kind of Y off the circulation loop; the coolant doesn't run THROUGH the bottle (exit the loop into the bottle and get picked up from the bottom) but rather runs through an open loop to which the bottle is connected kinda on the side. I replaced my MECS pump at the start of this even though I'd had the new design to begin with and can detect no other evidence of cooling system problems; pump runs fine, I can feel movement through the lines, and in fact I can watch the G_PHTMP temp recover incredibly rapidly if I let off the accelerator (it does climb, but drops 10s of degrees in seconds).

Part of the reason I still have the occasional wrench light "motor electronics overtemp" warning is that I am becoming increasingly convinced its a sensing problem and not an actual temperature issue.

All that said, there IS still a decidedly unfortunate set of temperature management choices- the fluid in the the PTU gets cooked by the catalytic converter right next to it and changing it requires a pump since they didn't bother with a drain plug ( "lifetime fill" my ****). And there really should be a trans cooler for a system that contains not one but two sizable electric motors. I've even thought about scrap-yarding the trans cooler from the V6 model's lower grille, (behind the bumper) but haven't come up with a good way to move fluid through it. Getting to where the gear pump is in the hybrid transaxle would be....major.

 

I just took to a short freeway drive and the first few miles the temps were still cool the weather is i got the triangle. Took the exit and restarted twice worked the second time check engine light came on code is p2196:00-ec. Oxygen sensor signal biased/stuck rich bank 1 sensor 1.