I am having an unexpected seemingly serious problem with my 2005 4WD FEH at 75,000 miles. It started in early August when I was driving around 70 miles per hour for a prolonged period on the freeway, with some occasional aggressive passing of trucks. I suddenly got the triangle with the exclamation point and the "slow down and stop safely" message and it went into "limp home" mode (electric only). I pulled over to the shoulder, drove till I got off at an exit and stopped at a gas station. After sitting for about 10 minutes, I turned the ignition, the ICE started back up, and I got back on the freeway and drove for about 1 hour more, but made sure I stayed at 65 or lower.

I took it in to the dealer and the hybrid mechanic suggested I replace a cooling pump that was working at below capacity. He also flashed the bios and they replaced an emissions sensor that had wires chewed through by a rodent (and had caused the service emissions message to turn on). He told me the car would go into this mode at even the slightest sensing of something wrong in order to protect its very expensive systems, and that if it happened again, just come to a stop and start it up again and the ICE should run.

About a week later, it happened again, again on the freeway, again at 65 or 70 MPH. I stopped, waited a few minutes, and then started it again and continued about 10 more minutes, at a slower speed (a very hot day - thought maybe there was a heat issue). Then when I pulled off the freeway at an exit, it shut down again (and displayed the same warning sign and message). Re-started after a 5 minute wait, we got where we were going, parked the car, and drove home that evening when it was cooler without incident.

At this point I was thinking it was a high speed or temperature issue. I normally don't get much over 50 MPH and drive back roads to and from work in my commute, and never had this behavior at lower speeds in my normal commute. My commute is only 30 minutes, though, and each of these incidents occurred 1 hour or more into a road trip at higher speeds sustained for a while.

Two weeks go by, and this weekend my wife was driving across the state (2.5 hour trip) and the shutdown occurred again, on the freeway; she stopped, restarted, and it happened again; she waited about 5 minutes, restarted, and was able to get to her destination. Then on her return trip 2 days later, on the freeway (but staying at or below 65 MPH) it happened again.

I'm going back in to the dealer now, but am wondering if anybody is aware of similar behavior or has any ideas as to what is happening.

 

Any wrench icons that you've seen over the past few weeks/months. Ones that come on, but go off at the next restart?

There seems to be an occasional problem with what I THINK is called the Battery A/C mixing door actuator on these things. I've never heard of it causing a shutdown. Usually the symptom is that that you have a wrench icon that clears on every restart and comes back occasionally. Its hard to find for the dealer because the icon clears AND so does the code (IT SHOULDN'T but it does). The only way the dealer can read the code is if the vehicle is taken to them with the light ON and they DON'T turn the car off before reading it.

In any case... I'm wondering if such an actuator finally failed and the A/C battery mixing door were shut.... would the battery get any air? That would be an overheating problem..

 

This sounds like the coolant pump problem. You said they suggested you change the pump - did they? Also, the problem could be with the pump itself, or the ground connection. If the problem was the ground connection and they just replaced the pump, the problem won't go away.


Any rodent-chewed wires they found may also mean there are others they didn't.

 

Thanks both of you for responding.

TeeSter, I have not seen any wrenches that have come on then gone off.

DesertDog, they did replace the coolant pump. They said it was working, but it was pumping below its proper capacity, and they recommended replacement so I let them do it. They showed me the reports relating to taxis having shutdowns after much higher mileage than I had and mostly city driving and it being related to the coolant pump failure.

They also gave me printouts of the Ford database reports they found regarding issues that might be related and none of them except the coolant pump seemed pertinent. I spoke about what happened to the hybrid mechanic so he understood I was interested in what was going on so he gave me more info than he probably normally would.

Anyway, I will take it back in and see if they can find any other chewed wires or a ground problem. Can you elaborate on the ground connection you are referring to?

 

on mine when it shut down on my wife on the freeway i left it with the dealer and they had to drive it around for a few days with the computer hooked up till it did it again so they could find the problem, they replaced the electronic throttle body, mine had 45000 miles when this started happening, it was an ittermiten problem, it happened a couple of times before, but we havent had any other problems with it since. hope this helps

 

Helps us if we know what dealership you used...or at least what city you live in.....you don't have to name names, but information about a responsive, knowledgeable dealer can save us all headaches if we ever have that type of problem..............as we know, the level of hybrid knowledge in the Ford dealership service departments varies greatly.

 

Did you have the wiring harness recall done? That was related to shutdowns I think.

 

I don't remember what forum it was posted on, but someone had an experience almost identical to yours and the dealership replaced the coolant pump, then the entire transaxle assembly. It was during the transaxle replacement that the loose ground wire was discovered. As I recall the problem didn't return. The ground was for the motor electronics coolant pump.

If you have a scangauge you can monitor the motor/generator coil temperatures along with the motor electronics coolant temp. If the problem is with the pump, you'll see any odd behavior with the temps.

 

I had the wiring harness recall done.

I'm in Ann Arbor, Michigan and use Varsity Ford, one of the highest volume Ford dealers in Michigan.

 

Interesting that you use Varsity... I always used Palmer up in Chelsea and I'm kind of suprised you don't. I had some of the other dealers around here try to charge me over $200 to figure out a check engine light on a Ford Escort.... When I called Palmer, they said.... "its one hour labor... and if you fix it here it comes off the cost of the repair... HOWEVER, before you bring it in... check your gas cap. If its loose then that is probably the problem and you don't need to come in at all."

It was my gas cap... and that is a frequent KNOWN possibility... between trying to charge over 3x more than they should and NOT pointing out that I probably could solve the problem myself, I decided the other dealerships weren't for me.