What else could cause a TAC code

[Lupo222]

Besides the actual Throttle body electronics, what else could cause this code? Just the PCM or is there something else I could be missing??

By the way it's throwing a TAC forced idle code and will not turn over.

Could it be tune? Alternator? I'm so lost and not looking forward to buying yet another PCM

 

[J2L06GT]

Check gas pedal and wiring down there, remember reading, long ago,
someone had problem that ended up being resistors in pedal assembly
bad.

 

[Lupo222]

but would that prevent the car from even turning over?

 

[J2L06GT]

Don't think gas pedal will keep engine from turning over,
clutch safety switch or PATS would.

 

[Lupo222]

but would clutch safety switch or pats throw a p2104 TAC forced idle?

 

[J2L06GT]

Don't see how they could, have you done any rewiring, following
your post looks like you have multiple issues.

 

[BruceH]

Stock tb?

 

[Lupo222]

GT500 TB and no I haven't touched any wiring under there like that

 

[J2L06GT]

Have you checked major electrical connectors for any
moisture or corrosion, thats the problem with all this
high tech shit, doesn't take much to throw it wacky.
How much would we all pay someone for a throttle cable
conversion!

 

[BruceH]

GT500 TB and no I haven't touched any wiring under there like that

I'm just guessing here but is the tb accounted for in the tune? How did the code pop up, were you driving and it went into limp mode or just starting it or...

 

[Lupo222]

actually, the shop i took the car to took the pcm out to swap it and then it just popped up. never had issues with that code before. All voltage to TB checks out. The TB is good. Lito tuned and accounted for the GT500 TB. It ran great for about 6-9 months.

 

[J2L06GT]

Have you tried removing intake tube so you can watch TB butterflies
and have another person 'turn on key, don't try to start' then after
dash stop beeping, slowly push gas pedal down to see if butterflies
react, this should tell you if PCM has any control, also might try
wiggeling plugs on front of PCM at the same time to see if anything
changes. With battery disconnected might also look at plugs on front of
PCM to make sure all the pins look okay, none bent or pushed back.

 

[AutoXRacer]

actually, the shop i took the car to took the pcm out to swap it and then it just popped up. never had issues with that code before. All voltage to TB checks out. The TB is good. Lito tuned and accounted for the GT500 TB. It ran great for about 6-9 months.

Why did the shop replace your PCM?

 

[Lupo222]

the car was throwing a faulty o2 sensor code, and the driver bank wasn't reading any voltage .0001 or so at most.

The car started runing like crap because of it so I took it to a shop and they checked everything electrical and couldn't come up with anything so they determined it was the PCM (Yes, i changed the o2 sensors no less than 3 times myself).

After they removed the PCM, the company i ordered from sent me on that was supposed to have the same PROM (4 digit comp code) as mine. Well, assuming they ddi their job, i reloaded my tune. When the car wouldn't start, i finally realized this computer had a different code on it. I had Lito account for this PROM. It was STILL the wrong one. After reading the strategy i found it was a different prom than the sticker on the PCM. So after having 2 faulty programs on that computer, we got the right one and now im getting this TAC code.

 

[AutoXRacer]

I have been always told you can't swap PCMs...

Is this true? Something about coding the keys?? I was told you had to have the dealer recode the PCM for your vin number??

Again, just asking...

 

[Lupo222]

^ I did this. It's for the passive anti theft system

 

[Fallenauthority]

You need to datalog the following parameters if you can:
APPS1 APPS2 APPS3, while logging these PIDS push the pedal to the floor and see if your values are within the following ranges

APPS1
0.48 - 1.76
APPS2
2.95 - 4.62
APPS3
2.43 - 4.02

These should be the values for foot off the pedal:
APPS1
3.43 - 4.69
APPS2
1.13 - 1.88
APPS3
0.64 - 1.28

Report back and let me know and I will walk you through the next step of the pinpoint test if your values are within range of the above.

 

[Lupo222]

I can't. Cars 800 miles from me. Ford says it is not the computer because the computer is not registering the TB at all so he's checking the wiring from the TB all the way back

 

[Fallenauthority]

I thought you were getting it shipped to you? Guessing and throwing parts at it from "guess a part" diagnosis isn't going to do you any good. Get the car to you. We will help you actually diag the car instead of playing pick a part and replace.

 

[Lupo222]

Welp, good news and bad news...the throttle body itself is bad. They put a stock GT throttle body on it and it ran just fine.

So now I need to find a GT500 tb (with electronics) asap.