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Discussion Starter · #1 ·
So today I disconnected my battery to work on some minor things, didnt really need to as i just changed the belt and alternator wire. Well. After i reconnected the battery and started the car reved it and it revs. I turn the car off to gather up my tools and stuff and to close the hood. (could of left it running sure).

I start the car again and boom, service light is one, battery light is on, ABS light is on, engine light is on, and there is ZERO throttle response. i turn the car off and relax for a bit thinking. Why is this happening? i turn the car on again i get maybe 200rpm above idle of rev. I scan the car and have a P2112 code. Actuator stuck closed. Weird as i watched my throttle body clearly open wide when i press the gas and the scan tool even reads the actuator is opening. I turn the car off and do a "hard reset" on the car

I pulled the cables off and sat there for about 30 seconds, reconnected them turned the car on and still. No response. I went to AutoZone and got a new actuator and installed it. Still. No response. Same codes as before except this time, its claiming its stuck open and or closed. I called a buddy of mine and we adjusted the idle screw, nothing. pulled the TPS sensor, car ran rough, plugged it in car ran fine, removed the actuator wire car ran rough, plugged it in fine again.

He thinks the ECU is fried from the previous times the car was being over charged from voltage spikes and the issues have just now caught up to me. Could this be a possibility cause weve tried most if not everything we could possibly think of doing and still just no throttle response. AGAIN on my scan tool its responsive but to the car its not. Both TPS reads 86% at WOT, but the revs dont go higher than 900rpm.
 

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2006 Mustang GT
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It IS possible the ECU might have been damaged by the voltage spikes, but you could try finding a good used OEM throttle body in a junkyard or on Craigslist (with electronics attached of course) and see if swapping that in solves the problem.
 

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2014 GT, 1967 Fairlane GTA
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The P2112 code is Throttle Actuator A Control System - Stuck Closed. You may have a wiring/connector issue anywhere in the throttle actuator control system including the pedal sensor/assembly, TPS, actuator motor, TB, or the PCM. Any of these parts malfunctioning can also cause this code. There's some circuit check troubleshooting here: P2112 Throttle Actuator Control System Stuck Closed (obd-codes.com)
 

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Discussion Starter · #4 ·
It IS possible the ECU might have been damaged by the voltage spikes, but you could try finding a good used OEM throttle body in a junkyard or on Craigslist (with electronics attached of course) and see if swapping that in solves the problem.
Whats weird to me is both plates open up, and on my scan tool it reads the TPS is opened to 86% but there is no increase of RPMs at all.

The P2112 code is Throttle Actuator A Control System - Stuck Closed. You may have a wiring/connector issue anywhere in the throttle actuator control system including the pedal sensor/assembly, TPS, actuator motor, TB, or the PCM. Any of these parts malfunctioning can also cause this code. There's some circuit check troubleshooting here: P2112 Throttle Actuator Control System Stuck Closed (obd-codes.com)
I know what the code is which is why im confused, i replaced the actuator and still nothing. Both plates open but no response to it at all. The most of a response i got was maybe, 200RPM over idle. I pull either side of the connectors off the throttle body and it runs rough, put it back on and it idles fine . But again, no throttle response when the plates open.

The P2112 code is Throttle Actuator A Control System - Stuck Closed. You may have a wiring/connector issue anywhere in the throttle actuator control system including the pedal sensor/assembly, TPS, actuator motor, TB, or the PCM. Any of these parts malfunctioning can also cause this code. There's some circuit check troubleshooting here: P2112 Throttle Actuator Control System Stuck Closed (obd-codes.com)
The car drove perfectly fine there but as soon as i disconnected the battery and reattached it, now theres a problem.
 

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Discussion Starter · #6 ·
That's why we're all scratching our heads!
Yeah, like i said a buddy came out to help me and he has been working on mustangs since god knows how long, and even he was super confused. hes got a 1996 GT and was just baffled at whats going on. I dont see why a throttle body would just stop working after a battery disconnected and reconnected when its been done dozens of times.
 

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Try a throttle relearn procedure. You stated you reconnected the battery and goosed it and then shut it off. TB didn’t have time to learn. Disconnect +/- cables and put them together for a few minutes. Reconnect and go through a relearn. Just my thoughts. Thanks.
 

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I know what the code is which is why im confused, i replaced the actuator and still nothing. Both plates open but no response to it at all. The most of a response i got was maybe, 200RPM over idle. I pull either side of the connectors off the throttle body and it runs rough, put it back on and it idles fine . But again, no throttle response when the plates open.
I posted the full definition of the code for others to see it because you only typed "actuator".
Codes don't tell you to replace a particular part. They tell you that there's something wrong with a circuit or system. In this case the actuator is not the problem. One of the other parts I listed in the circuit could be the cause or the wiring or connections to them.
An electrical surge can cause a borderline functioning electronic part to fail if it was nearing the end of its life. There's no telling when a part that's electrical in nature will fail. It could just be pure coincidence that it decided to fail after you reattached the battery but even so it technically wasn't because you started the car immediately afterwards and it ran fine. It was the second start when something malfunctioned.
 

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Discussion Starter · #9 ·
Try a throttle relearn procedure. You stated you reconnected the battery and goosed it and then shut it off. TB didn’t have time to learn. Disconnect +/- cables and put them together for a few minutes. Reconnect and go through a relearn. Just my thoughts. Thanks.
Yeah I did that and it didn’t do anything, I got throttle back after holding the gas and going on off on off 5 times. Then I cranked it and I had throttle again and the codes were cleared. I’m not sure why this happened out of no where
 

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Yeah I did that and it didn’t do anything, I got throttle back after holding the gas and going on off on off 5 times. Then I cranked it and I had throttle again and the codes were cleared. I’m not sure why this happened out of no where
So if I’m understanding you correctly, it’s all fixed for now?
 
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Discussion Starter · #11 ·
So if I’m understanding you correctly, it’s all fixed for now?
Correct, for now. I’m gonna run tests over the week and see if I can replicate the issue. Gonna have a electrical shop look at it Monday to ensure what I did was set right and everything. But yeah this issue is “fixed” until next time 😂
 

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Yeah I did that and it didn’t do anything, I got throttle back after holding the gas and going on off on off 5 times. Then I cranked it and I had throttle again and the codes were cleared. I’m not sure why this happened out of no where
As @Cobrajet67 mentioned, there may have been nothing wrong with the original throttle body actuator in the first place, although it was reasonable to assume at first that there might have been.
It seems that the real problem could be the accelerator pedal position sensor. For now you seemed to have solved it but if it recurs, I'd suggest that's the part you'll need to replace.
 

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As @Cobrajet67 mentioned, there may have been nothing wrong with the original throttle body actuator in the first place, although it was reasonable to assume at first that there might have been.
It seems that the real problem could be the accelerator pedal position sensor. For now you seemed to have solved it but if it recurs, I'd suggest that's the part you'll need to replace.
I also was just thinking that the pedal sensor could be the next likely candidate.
It could possibly also be what gladams said too about the PCM not being able to relearn the throttle since he hooked the battery back up, started it, revved it, and then turned it off quickly. After this issue came up the OP said that he only pulled the battery cables off for 30 seconds to try to reset the PCM but that's not long enough in order to reset and get it to relearn. The PCM memory has to be drained and 30 seconds isn't going to cut it.
 

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So today I disconnected my battery to work on some minor things, didnt really need to as i just changed the belt and alternator wire. Well. After i reconnected the battery and started the car reved it and it revs. I turn the car off to gather up my tools and stuff and to close the hood. (could of left it running sure).

I start the car again and boom, service light is one, battery light is on, ABS light is on, engine light is on, and there is ZERO throttle response. i turn the car off and relax for a bit thinking. Why is this happening? i turn the car on again i get maybe 200rpm above idle of rev. I scan the car and have a P2112 code. Actuator stuck closed. Weird as i watched my throttle body clearly open wide when i press the gas and the scan tool even reads the actuator is opening. I turn the car off and do a "hard reset" on the car

I pulled the cables off and sat there for about 30 seconds, reconnected them turned the car on and still. No response. I went to AutoZone and got a new actuator and installed it. Still. No response. Same codes as before except this time, its claiming its stuck open and or closed. I called a buddy of mine and we adjusted the idle screw, nothing. pulled the TPS sensor, car ran rough, plugged it in car ran fine, removed the actuator wire car ran rough, plugged it in fine again.

He thinks the ECU is fried from the previous times the car was being over charged from voltage spikes and the issues have just now caught up to me. Could this be a possibility cause weve tried most if not everything we could possibly think of doing and still just no throttle response. AGAIN on my scan tool its responsive but to the car its not. Both TPS reads 86% at WOT, but the revs dont go higher than 900rpm.
You stated you changed the alternator wire...What did you do?

Sounds to me like the new alternator wire is the issue unless you sparked the positive wire to the alternator body or ECU ground...

The ECU ground wire a ground wire that goes from the battery negative to the unibody is pretty important so Id go over the battery wires and ground wires and the wires were replaced with proper gauge wires to handle the amperage...

One time I had a neighbor that reversed the battery wires looking into outerspace most likely when changing his battery and some how the car started when he reversed them back but not good and kinda like your issues also to mention soon after his ECU went kaput so hopefully you didnt accidently reverse the battery wires or spark the positive to the alternator body because even a tiny tap does damage to the inner diode inside the alternator also capacitors inside the ECU..

Id also look into the alternator body to alternator bracket ground if you removed the alternator or loosened the bolt......
 

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Yup, 30 seconds definitely isn't enough to reset the KAM inside the PCM.
It is if you do it my way...LOL

Disconnect the positive lay it on the negative get in the cab turn the headlights on turn the key to start and press n hold the brake pedal...

30 seconds will do the trick but I hold the key to start and press the brake pedal 1 minute just to be extra sure.....

This method works awesome in Dodge Hemi Pickups too

Usually its a bad sign when you can bleed down ECU memory in 30 seconds just by disconnecting the wire and would point to the capacitors not doing their job due to a voltage spoke as a possible culprit and fails the Capacitors to "OPEN"..
 
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