2006 Mercury Mariner Hybrid

Problem:

It has been warm – but not too hot. When I go 30-40 minutes of driving with the A/C on I lose regenerative braking and motor assist. Even when I turn the A/C off I cannot get the car to go back to hybrid mode. I will also say this about the A/C...it blows cool somewhat - not cold.

This issue has happened twice. The second time the problem occurred (today) it didn’t seem like it was a total loss of regenerative braking and motor assist – the gauge was moving just a little.

When this happens, the cooling fan seems like it NEVER goes off when the car is on. The cooling line going to HV battery seems to be cold.

I’ll see what happens in the morning – but the first time this happened I went out the next day to go to work and it seemed like all was well.

I bought the car about 4 weeks ago from the original owner. It has about 147k. It has been well taken care of- so it seems.

The only warning I have received is a tire sensor fault.

Please help – I feel like I am regretting this purchase. I am kicking myself for getting rid of my trusty and faithful Camry with 236k!

update.....Additionally to my first post above - I drove today and ran the car w/o AC. The day temp was warm. The breaking and motor assist worked the whole trip. However, once the car warmed up and the day warmed up, I could not get it to go in hybrid mode.

Andy

 

There's a bypass valve on the compressor that fails. Causes A/C to underperform any time you're below freeway speeds. Passenger compartment cooling robs rear evap of capacity, so it can't cool battery effectively.

You could also just be low on refrigerant.

 

I agree with the previous post.

Sounds really like a battery is too warm issue.
Now you need to figure out why.

Air filter? (Unlikely but easy to check).
Air door stuck (likely, but more difficult to check)
A/C low on refrigerant (possible, not Too hard to check or you can add some)
Battery Fan(s) not working (possible, a little hard to check)

-John

 

Failed fan(s) and blend door will throw wrench light/codes.

 

Ya... you could hope so... but....

My blend door was permanently stuck for about three years. It lit a wrench light only once in a while. IIRC the wrench light went away every key cycle, and probably only lit on the trips the car tried to move the door.

However; I would have expected the car to "test" the door every trip, but I guess it did not in the 2005.

 

It only throws a code when it tries to close, and it can't, which is the only time it matters.