So tonight I got my first Wrench light on the '10 FEH (we've been putting a lot of miles on it for lots of reasons in the past few days) after an approx. 150 mile round trip (MPG: 31.2) at highway speeds that exceeded the posted limits most of the time and averaged approx. 75 MPH with a couple of stints up to 90. I find that this car really does well on the highway at about 80 MPH, it's very smooth and its composure and controllability are excellent at that speed. Anyway, after the drive I stopped for gas at a local station and left the car ON in EV mode while I fueled the vehicle, which took a little longer than usual because I had a conversation with someone at the adjacent gas pump. The little orange Wrench that lives in the lower left corner of the cluster illuminated for about 10 miles after the stop. I shut the car off while at a local store for about 10 minutes and when I came back out the light was gone. I think Evap system/fuel filler flap got a little jostled and the light came on. After it went out, no troubles and it hasn't repeated.

I'm going to do FTM's procedure to clean and lubricate that flap where the filler nozzle goes into the capless system. If the light comes back I'll let people know and when I have time I'll get the laptop out and check the codes, but it seems to have disappeared on its own. I opened the fuel door and pushed on the metal plate with my thumb and it felt a little stiff, so I think it's sticking a bit.

 

Evap will pop check engine. It's part of emissions Wrench is something else.

 

Huh. That's weird. It's happened 2x after getting gas. Then it goes out by itself after a key cycle! But you're right the Wrench is "Throttle control/Powertrain. Illuminates when a powertrain fault has been detected. Contact your authorized dealer ASAP."

The strange thing is the car runs perfectly, I can't feel anything different. Time to pull the codes, thanks!

 

My wrench is permanently on with that P0AA7. Nothing has fixed it, sometimes it disappears and the car doesn't drive any different. Could be something like that.

 

It's weird, I've gotten it briefly 2x after relatively long highway drives at fairly high speeds > 80 MPH in some places. The car is running great and I haven't gotten any other warnings, the diagnostic computer reads A-OK. Strange. I'll let everyone know what I find.

 

Im surprised it won't stay in memory. All my old codes stuck around till I cleared them even with DTC: not currently present

 

That's what had me going, thinking it was Evap related to the fuel door, because just pulling over and cycling the key made the wrench disappear. With any luck that means it's something goofy/intermittent. I'll know more by tomorrow. I almost didn't notice it because it happened during the day and the wrench light is kind of hard to see in the lower left side of the cluster in daylight. There were no other chimes, bells or whistles.

 

Update: I haven't put the laptop on it yet because I've been fixing another "new to us" car. But the wrench light has not come back, and even more interestingly, the Hybrid is posting very good combined mileage: It's sitting at 32.8 MPG average mileage right now with about 125 miles since it was last reset, in a wide mix of driving including city and highway, and that is dead bang in the middle of where it was EPA rated new.

Cooler outside temps. with daily highs in the 70s and nights into the low '50s have meant less load on the electric A/C compressor and better thermal management of the battery, I surmise. I also have not seen any self-discharge events on the Info. screen, and the car starts in EV mode every time. If I had any doubts that it's heat that does these battery packs a disservice, I don't have them any more.

Tomorrow I will have the chance to run FORScan with the laptop. I may run another Battery Balance.

 

I was just curious if there was an update on this issue. I had the same thing occur. I replaced the electric engine cooling pump. However, just like you, I have noticed the wrench light comes on when it is warmer outside (above 75), or at high speeds of 75+. The light goes away when I power the car off and back on. It usually stays off. Other than this issue it runs like a freight train. Thanks!