So we had some interesting things happen last Friday which turned into some immediate service before a trip we were leaving for that day.

About a month ago when the temperatures started to heat up a bit, we decided to finally test the A/C (we bought our FEH in November and hadn't been in any warm weather conditions until recently). At first, it seemed like things just weren't getting cold, and we soon realized that the A/C wasn't working at all. Fine, a little annoying as it's getting hotter out, we were going to take it in and have it looked at. We took it in, and the tech said we'd have to schedule an appointment for them to look at it and see why it wasn't working, but that it was just a comfort thing.

About a week later, we noticed that in the afternoons, we could no longer go into EV mode at all... We'd let it sit overnight, and it'd work properly again in the morning.

Now on Thursday things heated up outside quite a bit more, we'd gotten our oil changed and not too long afterwards we noticed some very disturbing behaviour. We'd put our foot on the gas, the car would jerk a bit and slowly putter up to speed. We were not getting any assist at all, and taking our foot off the gas did not send the usual charge into the battery... So just to test, I put it in L, and did a fake-shift once I actually got up to speed a bit, and absolutely nothing happened. It was as if I wasn't in L, the transmission behaved no differently than it would have in D, the car just coasted, not charging and not slowing me down at all.

So we went in to a dealer first thing in the morning, explained the problem, and also explained that my theory was that everything but the transmission problem was related to the A/C being broken (even though a tech had previously INSISTED to my wife that the A/C does NOTHING with the hybrid portion of the vehicle and is PURELY for comfort).

A couple hours later, I called to see how it was doing, and they informed me that the A/C was EMPTY! How does that happen? I would assume a leak of course... they'd 'recharged' it as they said, and injected a dye to find a leak... another hour later and they could NOT find any sign of a leak... and their call into Ford had confirmed my theory.

Now everything is working as it should, we have working A/C, and we've found a dealer that we can go to on a regular basis (we've had some issues with our previous dealer and the people where we had it fixed were really nice and were actually helpful).

I'm still interested to find out why the A/C was empty... we went around 1400km on the highway with the A/C running on and off with no issues. I guess I'll see in time if there's a slow leak of some sort that they weren't able to find.

So I guess the moral of the story is that if you notice that your A/C is not working and someone tells you that it can wait, insist that it can't wait as your FEH will no longer accelerate as expected (which is a little dangerous crossing traffic). I really wish that people were trained properly on how the vehicle works so that they can prevent issues like this in the future.

The only thing I don't understand is why the transmission was behaving the way it was. I mean I understand why I couldn't go into EV with things not being able to get cooled in the back, but I would have still expected driving in L with my foot off of the gas to slow the vehicle down. Any theories on this one?

At least everything is working as expected again...

 

If the HV battery couldn't be cooled, it was probably disabled by the system once it reached max temp to prevent damage. So no assist, but also no regen. Seems to make sense given your description.

 

I think randykato is right. A .pdf from Visteon someone posted here shows the cooling system for the battery. It has a coolant loop. The A/C keeps the battery in a pretty darn tight temperature range. This is how they get 100,000 miles out of it. Its even possible for the engine to kick on when the cabin A/C isn't on in EV mode (so the compressor can cool the battery).

So.. It makes sense that the battery might have gotten out of its temperature range and the system shut itself down to protect itself.

 

Yes, but does it actually explain the transmission problem where with the foot off the gas in L, the eCVT didn't slow the vechicle down as it normally does? It simply coasted as though it would in D.

 

I think it does.... the regen was disabled because the battery was too hot and the system didn't want to heat it up further by "charging" it with the regen.

 

In case that post didn't make sense (woudn't be the first). In low the eCVT isn't whats causing the "drag" feeling. The L gear sets the FEH to start regenerative breaking earlier (essentially whenever you lift the gas at slow speeds). That regenerative braking would charge the battery which is too hot because the cooling system is broke.

 

Ok, I guess in that way, it would explain it. I guess my assumption was that the slowing down was not entirely regen, and was similar to the way you would slow down in a 'lower' gear on any other vehicle.

 

Somewhere on this forum someone explained that the "L" gear is basically all electronic and I *THINK* they also said it was mostly regerative braking.

From my experience watching the NAV system and the regen guage, they both show recharging when you lift your foot in "L" gear... In "D" they don't unless you are going downhill. So I think it makes alot of sense.

It takes a bit of getting used to the fact that we own a vehicle that NEEDS the A/C to work properly...

 

If the battery is at max temp with no A/C cooling, it will not permit regen to over heat further. Shifting to "L" will have no effect. I drive EV in hot weather and have found the same conditions with a fully charged A/C. Everyone must know the limits, if you push the limits. Having an A/C problem is serious in hot weather with the FEH. Look for water dripping from the lines near the driverside rear bumper in hot weather to confirm A/C operation.

GaryG

 

There are AC coolant lines running to the back of the vehicle on the left side. This is the AC system for the hybrid battery. I would assume as the temperature started rising the battery was not getting cool enough to allow EV mode. I've seen other posts on this site about various issues with service. Seems that we know more about our vehicles than some of the service techs.

I'd keep a close eye on your car to make sure no permanent damage was caused to the hybrid battery as a result of not having refrigerant in your AC. The battery warranty should be long enough to cover any long term issues. Not sure what your warranty is in Canada. Here in California the warranty is longer than other parts of the US, 10 years/150,000 miles.

Good luck.