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I am going to try and paint an accurate picture of what is happening so bear with me; I have been having problems with my truck since February. One morning halfway to work, my truck loses power and throttle response, MIL lights up, and info center says "engine failsafe mode". I do my research and narrow it down (via borescope camera) that my IMRC is fubar. Due to finances and distance to work, I start driving my wife's 03 heritage edition and she drives my 05 Lariat to her work less than 1/2 mile away.
Fast forward to June, I finally found someone I trust to replace the IMRC and replace spark plugs while I borrow his truck. When done, the truck idles like a dream and the code is gone. Go for a test drive and within a mile, boom, truck goes into failsafe mode again. It does run slightly better and I can get to hwy speeds but it stumbles upon initial acceleration and chugs and pops through TB and eventually starts running "clean" and accelerates. Check DTC's and they indicate VTC's need replacing. I learn about unplugging them and do so with no change. I search for the best deal on OEM units and order them from Landmark who advertises over and over they are OEM. Well, they are not but I go ahead and install them figuring to replace them later with OEM. Go for a drive and within a few miles, MIL and failsafe are back and truck is running like it was.
Now, I'm getting DTC's of (in order) P0020, P0010, P0102, P0135, P0155, P2106 with the 1st one being the priority. That code is telling me my VCT's need replacing...WTF?! I'm looking for info from this group such as similar situations, suggestions, and hopefully a fix. Any help will be greatly appreciated and, if I can come up with a way, reward the fix with a cold beverage of your choice. One more thing; I ran motor flush through my engine (exactly per instructions) and the did my oil change with 5W20 Valvoline full synthetic and a new WIX filter.
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Ford DTC Decoded: P2106 - Throttle Actuator Control System
It appears to point to a o2 problem for one , heater fuses may be blown on front o2 devices .
That will screw up response of o2 sensors.
It also points to maf problems and throttle body problems .
I would clean both with the proper spray first . Look for air leaks bypassing maf stream . Or blocked filter /intake .
A limp mode is quite often because of failed throttle body . These trucks are fly by wire no linkage to throttle . If the throttle body is sticking for any reason the limp mode tries to prevent you crashing from a runaway throttle.There is a circuit card and motor inside plus other mechanical points to fail .
My throttle body failed at 60kmiles ,05's had a bad series from the factory.
Check all fuses you may have an o2 wire burning on exhaust manifold .
I wonder if you have vacuum leaks. Intake manifold gasket etc .Not knowing how IMRC job was done.
Most of us now use 5w .30 but that's more of a long term preventative not a fix . There is a lot more to check .
P2106 is the priority, but it's likely got nothing to do with your vcts.
what all those codes have in common though is the sensors are all powered through fuse #32. Have you made sure it's good and has voltage going out to it?
IF fuse 32 is good I would be looking for a damaged wire that's corroded, pinched, melted, shorting to ground partially or otherwise causing low voltage to all the sensors mentioned in the above codes that were posted.
Last edited by needsmoarturbo; 08-05-2023 at 12:25 AM.
Not sure if this will help, but you did mention air flow:
I chased a similar issue on my 1994 Ranger. It would idle fine and run down the road at lower speeds nicely, but when you stepped on the gas, it would cut out completely like you turned the key off/on. I chased this problem for weeks.
As this truck used to sit a lot, it turned out that an $&!* spider built himself a home inside the MAF and made a nice web right in front of the air channel going to that sensor! I took the MAF apart several times to check and clean but this nest was behind a small plate that I never removed. This is where that air channel was blocked.
After I evicted the arachnid, the truck runs perfect to this day! Too bad I didn't have a 'check spider' light on the dash - it would have saved me a lot of time and trouble!
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PS: If you do have to buy new VCT's, Amazon has Ford OEM's for $40 (price as of 8-11-23). I bought these same ones when I did my timing job and they are genuine.
Ford DTC Decoded: P2106 - Throttle Actuator Control System
It appears to point to a o2 problem for one , heater fuses may be blown on front o2 devices .
That will screw up response of o2 sensors.
It also points to maf problems and throttle body problems .
I would clean both with the proper spray first . Look for air leaks bypassing maf stream . Or blocked filter /intake .
A limp mode is quite often because of failed throttle body . These trucks are fly by wire no linkage to throttle . If the throttle body is sticking for any reason the limp mode tries to prevent you crashing from a runaway throttle.There is a circuit card and motor inside plus other mechanical points to fail .
My throttle body failed at 60kmiles ,05's had a bad series from the factory.
Check all fuses you may have an o2 wire burning on exhaust manifold .
I wonder if you have vacuum leaks. Intake manifold gasket etc .Not knowing how IMRC job was done.
Most of us now use 5w .30 but that's more of a long term preventative not a fix . There is a lot more to check .
Thank you for getting back to me with a lot of good info. I recently transitioned away from my summer job back to my fall/winter/spring occupation and haven't had much time to dig into the problem but I will post my results when I get her running like she should. Now I have a path to follow. To fill in a couple things; the friend that did the IMRC is very meticulous and thorough so I'd be very surprised at a vacuum leak. Also, when I first started having troubles, I pulled off the throttle body and gave it a thorough cleaning with the proper solvent/spray and afterwards it ran good until I tried to accelerate the boom, failsafe mode.
08-04-2023, 01:27 PM
05 Lariat with 5.4 3v having VCT problems
