Hello FEH owners I've got a 2009 Mariner Hybrid with 120,000 that needs to have the AC looked over, I'm not getting regular cooling to the battery pack but the cabin is fine.
Could be a compressor valve issue or something else and I'd love to bring it in to someone already familiar with it.
Any recommendations are appreciated

 

How do you know it's not regularly cooling the pack?

 

With the outside air temp in the mid 70's the battery case was low 100's (temp gun)
Wasn't going into hybrid mode after driving around but working well at start up in the morning.
the refrigerant lines to the rear were never cool to the touch like the lines under the hood
I got a stop safely now on a hot day driving through LA (had a full load 94 degree day) started up again about an hour or so later after it cooled down.
I don't have a scanguage to verify but my hunch is poor cooling, the fans are running and the blend door looks like it's working.
The cabin AC is fine, a little weak at idle but not horrible. so I'm leaning toward compressor valve but would like it verified by high and low side readings by someone who's already familiar with FEH
Thanks!

 

Case is internally insulated. Exterior temperature is going to be the interior temperature of the cargo area and 100°F on a 70°F day is not out of the ordinary even with functional A/C.

Scangauge won't do anything for you. SSN is a major issue and should be investigated immediately. You have (had) DTC indicating the problem. You may have the codes indicating cooling fan failure. You need Forscan or a professional grade code reader.

There is nothing special about the 09 FEH A/C system. Any competent shop can diagnose the A/C. You'll likely never find a shop willing to swap out the control valve, hybrid or not. Not enough profit in it. A/C that just "feels a little weak" typically isn't the control valve. A dead giveaway is crappy A/C (almost nonexistent) at idle, but it works very well at highway speed.

Stop using cabin A/C and see if it improves. The car will cycle the compressor as it needs it to cool the battery while you stew in your own juices. If that improves hybrid function, you likely just need a top-off with refrigerant.

 

Thanks S Keith
When hit the AC if in hybrid mode the ICE starts and you can hear the compressor kick in and see it as well
My MMH will not turn on the compressor unless I do it myself. Driving around on a hot day, I'll pop the hood and I've never seen the compressor spin on it's own, and neither of the refrigerant lines to the back are ever cold to the touch
I wasn't sure if there was a thermistor in the battery pack that just never sent a signal or if it's something else, others have mentioned the bypass valve as a common fail item.
The cabin AC works well at speed and just OK at idle.
After the SSN issue my battery mechanic who wasn't too familiar with the AC didn't give the actual code but said it was a battery overheat.

 

1) If true, then your battery cooling system is malfunctioning as it will cycle the compressor even if cabin air is completely off. The more likely case is that it requires MUCH LESS A/C to cool just the battery vs. the cabin, so the cycling is much less frequent, and you've simply missed it.
2) Possibly the control valve. "just OK" sounds a little too good for what I've seen. "Barely works" is a better descriptor of my experience.
3) "battery mechanic?" What's that? Overheat codes are pretty rare. Failed fan codes that are misinterpreted as overheat codes are much more common.

When you remove the battery inlet air filter, is the bypass door closed?

 

A hybrid repair shop was the battery mechanic, I was hoping they'd have a good understanding of the AC cooling system but they didn't, he's the one who read the code and simple said I had a "battery over heat" code
When the car and battery are hot I can hear the fans and the blend door is closed, The AC will not go on unless I ask it to cool the cabin.
If I had a leak I feel like the cabin air would never get cold and that's not the case, but for some reason the refrigerant isn't circulating back to the rear as it should
Thanks for the help

 

Ah. Again, there is absolutely nothing special about the 2009 FEH/MMH A/C system. It is indistinguishable between a standard SUV with a rear evap for rear air cooling.

Leaks are often slow with their symptoms progressive. I have literally topped off 100s of Prii due to slow leaks. All 6 of the Prii I've owned need periodic top-offs. This gets MUCH more common as they age.

"fan" sounds just like "fans". It is almost impossible to tell if one fan has failed. If one fan fails, half the pack overheats accompanied by a fan control error depending on left or right side (can't remember which is which).

If you don't turn on cabin climate control, there is ZERO indication of compressor activiation for the driver except for the click of the clutch and the potential loss of power. I am not confident that you can definitively say it's not working unless you spend 30 minutes parked with the car on and as many electrical accessories powered (A/C off, but blower on max speed), the battery knowingly over 90°F, and you observe at least three engine start/stop cycles for HV charging with no compressor engagement, and you observe the compressor the entire time the engine is running.

Based on your symptoms, I would conclude:

1. Failed control valve or low refrigerant
2. Failed fan

 

Just tested the two fans with forscan and with the cover off, they are both OK, It's going to be very hot here soon so I'm going to a local AC guy
We'll see

 

Awesome. Any DTC?

You can now see the battery EVAP temp in the BCM data as well as battery temps.