Hello all. First you should know that I have little to no mechanical knowledge/aptitude but I catch on pretty quickly


So my Explorer is a 2004 Eddie Bauer v-6 with about 93K miles, great condition, very clean and never had any issues. I've had it about 6yrs.


For maybe 3-4 years now the truck has seemingly randomly gone into Engine Failsafe Mode in the message center. I haven't noticed any pattern here as to when/why this occurs. The wrench icon lights up as well as the Service Engine Soon light. Sometimes I seem to notice a change in power/performance but often I don't. There are times when this happens every few days, and sometimes it goes weeks without occurring. Often it just goes out of Failsafe Mode after I've turned the truck off and restarted and seems fine again. For all of these years this has been a nuisance more than anything and so I assumed(hoped) it was just a sensor issue and nothing to be worried with.


A few days ago the truck actually shut off while driving...losing power, immediately after it kicked into Failsafe Mode while driving slowly down a straight road (no inclines or anything). Today it went into Failsafe mode, and it kept running, however the gas pedal did nothing...I couldn't accelerate at all though I still had power. Coasted to a stop. Turned truck off, started right up and the gas pedal worked fine. 15 minutes later same thing...this time when I coasted to a stop...I noticed that when I put truck in reverse I WAS able to back up using the gas pedal but couldn't go forward. Turned truck off, ran fine though still in Failsafe Mode...drove home where it sits now. Don't really wanna drive it now though I need it as my only source of transportation. I did have the scan done on it at Autozone a month or so ago and got the P2106 "Throttle Actuator Control System--Forced Limited Power" reading...which of course means nothing to me...and the guys who worked there had no idea either. I had the oil changed at Midas yesterday where they checked fluids and all that good stuff...I mentioned it before hand and they said they looked at anything they could and couldn't find anything without running diagnostics on it...I didn't have them do this as it is quite costly and at that point I hadn't experienced the issue with losing acceleration/gas pedal functioning while driving down the road.


Sorry to write so much, just trying to give as much info as possible. The vehicle has never ran hot or had any issues, it is routinely serviced at Midas for oil changes, fluid checks and everything they include in their oil change....the manager yesterday told me it looked great with no issues they could see without diagnostics or digging into it. Thanks in advance for any help/suggestions as I have to get this issue fixed as economically as possible (don't we all??)


Thanks in advance for your time and assistance.

 

The first thing I would do is remove the throttle body and clean it out. Both of my 04's have had lots of buildup around the throttle plate and one of them threw idle codes and wrench light when the plate was hanging up on crud in there. Cleaned it out and it idled better than ever. Otherwise there is likely a fault in the pedal assy, throttle body or the wiring in between. Salvage yards are full of these and the failure isn't common so cheaper parts are out there if you need them.

 

According to this guy, there are other causes of this fault that are not too nasty to find.

 

MilMachine--Thanks a lot for your suggestions and especially the video link.


You said that your '04s were throwing out idle codes...I often get the "Low Oil Pressure" in message center...check the oil and it's fine...just got that message last night after having the oil changed the day before...so it sounds like you could be on to something. Did you ever have your trucks lose power while driving or shut off or have any of those gas pedal issues I mentioned?? Thanks


Hopefully I can dig into this with a more knowledgeable buddy but any more info/suggestions in the meantime would be greatly appreciated.

 

Never had one with the message center, but the low oil pressure would concern me. Does your engine rattle or have any clicking sounds that are louder at idle or while accelerating?

 

No never really any rattling or clicking....drove it today...went into Failsafe Mode several times...one of those times the truck sort of bucked...like I had hit something underneath almost...like a jerking...then power stayed on but I lost use of the gas pedal. Pulled over...turned it off, started up fine and gas pedal was fine. It jerked or bucked a few times today when it went into Failsafe...that's been rare.


Based on my research on here and other places I'm thinking maybe it's the Throttle Position Sensor (TPS) failing. Most of the symptoms I've read about match mine...including a loss of gas mileage which I've lost probably 5 mpg over the past few years despite new tires, new air filter etc that I couldn't figure out why that was happening...I read that this is even a symptom of TPS failing. Anyone know how difficult this is to change (for a total newb even)??

 

Your tps is part of the throttle body assembly and is not separate. It is not cheap either. The fact that it resets with the key and does it with driving tells me you might have that speed sensor issue in the video. The one in the video was covered in fuzz from a probably failing differential. Either way the guessing game is expensive so I recommend a real mechanic with a good scanner that isn't a midas type place, otherwise we are all just guessing with you.

 

UPDATE**
So after further study/research and extensive googling and thread and article reading, I became convinced that the Throttle Position Sensor (TPS) was the most likely culprit. I found that the TPS is, in fact, a separate sensor that bolts onto the Throttle Body, I got a 30% off coupon code online and got the $70 part for $52 after taxes...ordered and paid online, picked it up at the store down the street 15mins later.


Put the new TPS on, didn't take long at all, only difficulty was in being sure it was positioned exactly correctly and fully engaged with the TB Tang. Once it was on, truck started right up, the Service Engine light was still on...drove to Auto parts store and had them reset the memory....all of the lights and warnings and messages in my message center were gone after they reset codes. Turned truck off for a few, had them scan it again for any new codes...the new scan came up completely clean...Service Engine Light is gone...Truck has driven perfectly with no lights and no Engine Failsafe Mode so far...only put like 20 miles on it so far so we'll see if it stays clean for the next few days...also curious to see if this improves my gas mileage which has dropped off hugely the past few years...from what I read it should make a big difference there too. Amazing that one very small, fairly cheap part could have been the cause of so much havoc on my truck... really for a few years but especially the past few days.


Thanks for your input, time and suggestions Milmachine. I'll try to update in a few days but I really think that TPS was the only problem. So hopefully this thread helps others as much as reading past threads helped me, a total newb with no mechanical knowledge/experience, to diagnose and fix the problem for, I'm sure several hundred dollars less than a shop would have charged (everything I've read tells me most shops would have wanted to replace the entire TB assembly). Thanks again Mil.

 

Give us the part number to what you bought. I sure didn't know it was available separately. That is good news.

 

Part # is EC3337


Drove the truck a bit today with no problems...no Engine Failsafe Mode and no Service Engine Light. Been a long time since I haven't had something lighting up or some errors in the message center.


As for the TPS it looks like it can be purchased even cheaper on eBay...maybe half of what I paid for mine... and that's after I got the 30% off!!!

 

Sweet. I would have just searched out a used throttle body without even looking for a tps, but sure enough rock auto shows it too. I don't see what the low oil pressure would be from unless your idle was so low that it tripped, but I hope it stays fixed for a good long while.