ETC failsafe now it won't start

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willfly4$

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I have searched high and low but havent quite found another example of my problem. 2004 LS V8, it first manifested itself as the ETC failsafe, it would restart but then die completely in ETC failsafe, this happened a few more times until it would just sputter and die when i tried to start it. after a few more times, it wont even start.

here is the odd part, it is in ETC failsafe as soon as i turn the key on. right when i turn the key on, the throttle is driven closed by the motor then the motor releases but the plate stays closed while cranking and right after that, the ETC shows its ugly head and the cooling fan kicks in full blast and my battery will almost go flat while trying to get the codes! (brand new battery) the codes are the usual PCM, throttle actuator and all that stuff but nothing about ignition.

its got spark and i smell a little fuel in the exhaust so must be the throttle plate being closed all the time due to the ETC? dont know.

things done so far:
1. put new coil in #4 position, no change so i walked it all the way around and no change, still wont start.
2. new throttle position sensor, no change
3. new spark plugs, no change
4. checked plugs on PCM, TPS, throttle motor, gas pedal and still no change.
5. checked for pressure on the fuel rail and reset the pump cutoff...no change

ive got 8 coils on the way but i really dont see how the engine is going to start if it doesnt even fire up as it sits now. any insight as to how i could clear the ETC failsafe without throwing any $400 frickin parts at it would be awesome.
 
Well, if you could post the exact codes, it would help. Maybe you actually have a defective throttle body. Knowing which codes you are getting and which ones you aren't would help to determine that. If your engine fan comes on without the engine running, then you probably have a PCM fault.
 
at first 0606, 1233, 1235, 2107, 2106 in addition to these codes the driver information center says check parking brake, traction and some other stuff. As it sits now after clearing the codes the pcm fault (0606) wont clear and i keep getting just one or two other codes which are always the throttle stuck closed or open.
thanks
 
let me try this question, how can i test to see if the gas pedal position sensor agrees with the throttle position sensor. the car obviously doesnt like the coamparison with these two and i really need to clear the ETC if im going to get this thing started. im just assuming that the throttle plate being driven against its stop then released is not normal.

also, i do have 5volts going to the TPS. I put a meter on the TPS when i took it out just for my own edification, at "idle" it read 6K ohms and just a little past idle jumped out of limits on my meter, as they say next door in louisiana, "whats da deal wit dat?"
 
I think there's a new PCM in your future. It looks like yours might be toast.

I don't know why you are wanting to look at the gas pedal assembly. There are no codes related to it. The PCM does not compare the gas pedal position to the throttle position. There's actually no big link between them. (You can be driving with the gas pedal pressed 1/4 way down, while the engine is at wide-open-throttle. The PCM decides where the throttle needs to be based on several factors, only one of which is the gas pedal position.)

The gas pedal has three position sensors in it. The PCM monitors to make sure all three always agree. You don't have any codes listed to indicate any problem there. You do have a code that basically says the PCM wanted to put the throttle in one particular position, but couldn't. This could be a problem with the throttle position sensor, the servo motor assembly that moves the throttle, or wiring, or the PCM. Since you have actual PCM codes, I say it is the PCM. Also, the fan coming on with the engine not running is an indication that the PCM has crashed/failed.

If you measured the TPS resistance by moving it by hand with it disconnected from the car, then it has a dead spot and is faulty. If you measured it while it was still connected to the car's wiring, then the measurements are invalid. You can't measure the resistance of something while another power source is driving it.
 
thats strange that the PCM would "progressively" die being as its a solid state device, but ive seen stranger things! im into airplanes and my airplane doesnt have a whole lot of computers so im just relying on research with this problem and so far ive found VERY few PCM failures and VERY few ETC problems that were fixed by replacing the throttle body. i understand that not everybody post there fixes online but thats all ive got right now. ill try another TPS today.

TPS was ohmmed while off the car. if i was measuring on the car i would be looking for voltage :)
 
willfly4$ said:
thats strange that the PCM would "progressively" die being as its a solid state device, but ive seen stranger things! ...
Click to expand...

Actually, it's a bunch of solid-state devices soldered together. The most common failures are soldering issues and coil drivers burned out by defective COPs. Anyway, PCM failure is extremely rare and as such the PCM should usually be the last thing to suspect. However, they do sometimes fail, and internal failure codes usually are correct.

There were some known problems with the 03 (and early 04) throttle bodies, but yes most often the problem is interference from the COPs. Again, there are exceptions.
 
new TPS and no change, i did compare the old TPS to the new one and im 99% it was bad. i checked the live PID data after installation and it is reading throttle plate position and shows a change when i manually move the throttle plate.

i checked the PCM last night, connectors, wires for chaffing, disassembled the box and looked at the solder connections going out the the plugs, all good as far as i can tell.

one question i still have is why the throttle plate is being driven hard against the stop everytime i turn the ignition on?
 
willfly4$ said:
...
one question i still have is why the throttle plate is being driven hard against the stop everytime i turn the ignition on?
Click to expand...

It sounds like the PCM is not reading the throttle position correctly. This could be because of a bad throttle position sensor (but you changed that out), bad wiring, or a bad PCM.
 
thanks for your help, earlier i called the local dealership to ask about programming a used PCM if i can find one, the service writer not surprisingly had no clue what i was talking about and then told me i couldnt talk to the tech that was standing next to him telling him what to say to me....

would my next step be to check PCM power, ground and v-ref circuits? if so, does anyone have a flowchart? ill be searching for one on the net.
 
Went back out just now and I got the car to NOT go into ETC fail safe when I first turned the key on, this lasted about 20 seconds before it went back into fail safe. It did this three times and got my hopes up before it petered out. The current codes are 0606 PCM, 1233 fuel pump off line, 1235 fuel pump control out of range, 2106 throttle actuator forced limited power, 2107 throttle actuator processor, 2135 throttle pedal position sensor switch a/b voltage correlation

After this, I went back to cleaning contacts and reseating everything I could.
 
There's one thing common to all that, the PCM.
 
Joe, I was just checking rockauto and they have a rebuild service for ECMs (i beleive they are talking about the PCM) have you ever heard of this service and is it worth it? it comes up in their catalog for the 04 LS8
 
willfly4$ said:
Joe, I was just checking rockauto and they have a rebuild service for ECMs (i beleive they are talking about the PCM) have you ever heard of this service and is it worth it? it comes up in their catalog for the 04 LS8
Click to expand...

No idea.
 
does anybody have access to the voltage drop test procedures (which wires are which) for PCM circuits on the LS? or does the maintenance manual just say to substitute a non-malfunctioning PCM to check PCM function?
 
willfly4$ said:
does anybody have access to the voltage drop test procedures (which wires are which) for PCM circuits on the LS? or does the maintenance manual just say to substitute a non-malfunctioning PCM to check PCM function?
Click to expand...

Dude, take it in and have a proper diagnosis done. It will save you money in the long run.
 
why would i have my car towed and stranded at the gnarly dealer when i can "possibly" find the faulty component myself and safe money by not buying $80 coils and $600 PCM and $500 throttle bodies? (prices are ballpark) their time is $90 per hour and my time is considerably less as long as there are no oil spills in the world that need to be sprayed :)
 
willfly4$ said:
why would i have my car towed and stranded at the gnarly dealer when i can "possibly" find the faulty component myself and safe money by not buying $80 coils and $600 PCM and $500 throttle bodies? (prices are ballpark) their time is $90 per hour and my time is considerably less as long as there are no oil spills in the world that need to be sprayed :)
Click to expand...

Because they have the proper diagnostic tools. That will save money by not throwing parts at the problem.
 
willfly4$ said:
why would i have my car towed and stranded at the gnarly dealer when i can "possibly" find the faulty component myself and safe money by not buying $80 coils and $600 PCM and $500 throttle bodies? (prices are ballpark) their time is $90 per hour and my time is considerably less as long as there are no oil spills in the world that need to be sprayed :)
Click to expand...

No it cost $100 to do a diagonistc. You dont have to get it fixed there.

Also if you get it fixed there not only will you get a guarantee on the work you could possibly get a loaner car to drive in the meantime.
 
I'm brand new to this forum but I have been reading a lot of posts regarding maintenance issues and such. I seem to think that there are some Lincoln mechanics here on the forums that might have access and be willing to help with me troubleshooting my PCM/Wiring. If we all took our cars straight to the dealer, why would we need a forum other than to talk about bling bling and which dealers threw parts and which ones test drove and actually fixed the car:)

I do appreciate everyones answers so far but I still would like to "wring" out my wiring to and from the PCM with a meter.

I am an aircraft mechanic by trade and while this obviously isn't an aircraft, I didn't give exorbitant amounts of money and time to be trained how to use a multimeter and a screwstick, then pay someone else to do it. I also have a scanner so I don't want pay $100 for their scanner, even if it is a super duper flux capacitor scanner.

If you gents want to take your car to a dealer, thats your call, but the mechanic in me won't do it until I need a new PCM flashed or something else that takes specialized equipment.
 
i just got a PM that led me to a download for a complete manual! I've got some studying to do and if I'm still alive or have any pride left after this debacle, ill report back....
 
alright, just an update, joegr got it! so far as i and a lincoln mechanic from justanswer . com can tell, the PCM is bad. It cost me $27 to do the diagnostics myself :) (with the help of just answer . com of course)

i got the complete service manual but found out that in order to get the pinouts for the voltage and ground tests of the wiring, i needed a Powertrain Control and Emissions Diagnosis manual for my car, when you look up the PCM in the service manual it tells you to refer to the PCED manual :)

i got on justanswer and although it took about 2 days, i finally found a lincoln guy that gave me all the pinouts and procedures, once i tested the wiring, the fault was isolated to the PCM. as far as the codes pertaining to the throttle body, the mechanic had me unplug the TPS and servo and make sure that the same codes were coming up, hinting that the PCMs ETC circuitry is faulty.
 
my PCM was repaired with the memory intact, no flashing required. after i installed that silver box of death, i turned the key on with ignition off, checked codes and it was clean with all PID data normal. i put 8 new visteon coils and new plugs..... started right up and purrs like a kitten!!! thanks for everyones help and i hope this will keep at least one other person from buying throttle bodies or TPS that they don't need.
 
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