I have an 08 Ford Escape Hybrid with 120,000 miles on it. We have had a hard and cold winter here in Cleveland and it has brought on many problems that I am not sure if they are related to the cold or to each other. A few months back, I had the common problem of the vehicle going into “electric only” mode all the sudden at 65 mph it would drop to 30 mph and a “stop safely now” message on the dashboard display. I changed the MEC pump with help from Youtube. Easy fix, $150. When that was going on, I noticed that I could postpone that event on longer trips so long as I could keep the RPMs under 2500. But I was finding that uncommonly hard to do. I thought when I fixed the MEC that would go away. It didn’t. In fact, it seemed to have gotten worse and my MPG dropped from 32 mpg down to 24 mpg. On a trip from Cleveland to Oklahoma recently, loaded for a 5 week business trip, my RPMS were swinging from 2000 to 4000 rpm with ever, even minor, incline. my MPG seems to have improved some on the trip though. Might be caused by the 40 degree increase in temperature. This is a CVT, so can’t use sluggish shifting to diagnose.
On a side not, I have an engine light on that the local parts store (who gives free computer readings) said points to an evap solenoid. This happened shortly after backing over a snowdrift that had gotten in my way over the night. Here is what makes this interesting. Internet sources point to a possibility that the EGR valve might be causing both the code being given by the check AND the loss of power. In fact this is a really strong possibility if I am reading things right. My system reports “energy: ok”.
Given that this is both a hybrid and a CVT, I think it would be worth your while to pay a diagnostics charge at a dealer for a full scan of the computer. The parts store readers are normally generic OBDII readers and that is all they pick up are generic OBDII codes. There are likely other codes in there that your auto parts store isn’t picking up.
As for the evap code, what you really need to post is the exact and specific code - format: “P0123” There are plenty of evap system codes. However, evap system malfunctions don’t normally result in any kind of driveability problems. The biggest possibility would probably be a ruptured vacuum line between the solenoid and throttle body, or if the purge valve is just stuck open. But that would basically act like a vacuum leak and produce more symptoms at idle. If it goes on long enough you’d probably also end up with lean codes.
As for the EGR valve - I can’t think of a single thing about it that would link it to the evap system and make it possible to trigger codes there. The EGR bolts onto the intake manifold with an exhaust feeder line. Based on info from the DPFE sensor and engine conditions, the PCM will operate a vacuum solenoid to open up the EGR valve at appropriate moments. It doesn’t interface with the evap system. EGR system problems can, however, cause power issues if, for example, it sticks open of something. But I seriously doubt it can account for the car basically going into an electric only / limp mode. I suppose it might. I don’t really know anything about the electric/gas interface systems. But let’s say a standard ICE malfunction (such as EGR) could send the car into this mode. Then that would mean the computer “sees” the EGR malfunction and you would have a code.
On the MEC, why did you replace it? Did you check it and find it inoperable? Is it now working properly?
Anyway, as I said I think you just have to bite the bullet and have a full scan on Ford-based equipment.
Wow, only just remembered that I had posted here. Thank you Cigrollar. All of your information was accurate. Lots has happened between here and there. First, I have learned that the MPG issue is a known one when the battery is cold. It seems the combination of 120,000 plus miles on the batteries and the very bitterly cold weather this year contributed to the MPG’s drop. Warmer weather brought them back up to the normal 34 mpg average I usually get.
The code I was getting was a P0446 code. The light went out the entire time I was in Oklahoma. On the last day, when I loaded the car down and prepared for the 1000 mile journey back home, the light came on and stayed on. I had learned that the “on again off again” relationship with my engine light meant that the Vent Valve was probably going and sticking. Back home, in my network of people I have convinced that I am cool to hang out with, there was a friend of a friend with a really expensive computer. I, running late for work as usual, stopped by his place, plugged it up and determined it was in fact the vent valve. Off to “partsgeek” to get a new one. Replaced it, annnnnnd… the light stayed on. Cleared the error both with the described “battery disconnect” technique and a cousins cheap code reader. the light came right back on. In the past it would take a few days. With a lot more time allotted, some beer, and a pocket full of cash, I went back to the guy with the nice computer, garage, and access to documents you can’t find on the internet. Found out the Escapes computer was functioning (wooo, that was close) and the vent valve solenoid was good. So it was the wiring in between. A shot in the dark with only it being the most suspicious spot to look at, he opened the 50 wire bundle that ran near the driver’s side shock tower and started tugging on the green ones using an electrical probe. Sure enough, one popped out. Spliced in a new piece of wire, and I am back in business. Found another wire in the same bundle that didn’t look all that healthy. and an IT tech, wiring issues are usually the lowest on the list. Wires just don’t go bad in the middle. But, in this case it did just that.
Thanks again for your response.