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camerontech, Auto Mechanic
Category: Dodge
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Experience:  diagnostic auto tech
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2001 Dodge Neon Automatic Transmission. Regarding the PCM

Customer Question

2001 Dodge Neon Automatic Transmission. Regarding the PCM module. Which PCM connector pin tells the PCM that the transmission is engaged, and what is the signal on that pin coming from the transmision. Example; +12V, Ground, a wave form [what is the wave form if there is one], etc.
Submitted: 1 year ago.
Category: Dodge
Expert:  Jerry replied 1 year ago.

Hello and welcome. My name is ***** ***** you for visiting the site, I will be happy to assist you today.


Let me start by saying that any money that you paid, or if you have a subscription, that money stays in your account until the answers are rated, (positive) regardless of how fast or how long it may take to get finished. You can FOLLOW UP AT ANYTIME, even after rating.


The Transmission Range Sensor (TRS) (Fig. 304) communicates Shift Lever Position (SLP) to the TCM as a combination of open and closed switches. Each shift lever position has an assigned combination of switch states (open/closed) that the TCM receives from four sense circuits. The TCM interprets this information and determines the appropriate transaxle gear position and shift schedule.


I can get the test instructions for it and put it in a PDF file, (it is rather large) and send it to your email address for a little bit more.


You will just have to accept the additional service offer and ENTER your email address in the private section so that I can see it. I do not have access to your email address, Thanks

Please don’t forget to rate the answer in a positive way, . EVEN IF YOU HAVE A SUBSCRIPTION ****THAT IS THE ONLY WAY I GET PAID ****



Customer: replied 1 year ago.
I apologize, but I must have phrased my question wrong, I will try to re-phrase it. Just a note, this is the second time I have submitted this question, and paid for an answer, the first time was about 8 months ago. OK, here is what I did that led up to my question. 2001 Dodge Neon "Manual Transmission" I forgot the name of the part, but it is a computer control module that sits behind the car's gril, just to the left of the radiator (driver's side). I think it is called the ECM PCM Control Module. That unit suddenly produced an ODBII code that said the units internal memory had failed. I went to a junkyard and found another 2001 Dodge Neon and removed its ECM PCM module and installed it in my Neon. The unit works great, I have no trouble with it, however, it is sending and ODBII error code P0743 [The Torque Converter Clutch (TCC) solenoid valve is activated]. My Neon is a 5 speed manual, not an automatic and does not have a torque converter. The error code is appearing because there is no wire attached to the PCM TCM pin number 78. I just need to know what the signal should look like on pin 78 if there were a torque converter in the car. I'm trying to fool the PCM TCM into thinking that "all is right with the torque converter". It may be that it is something that I can not duplicate, however, if it is expecting a ground or +12 volts, then I can set pin 78 to that signal level, then, hopefully, the PCM TCM module will be happy. Can you please tell me what that PCM TCM pin 78 signal should be? That is all I need from you. Thank you. Oh yes, I forgot, is Pin 78 the correct pin, I found it through my research. I really wish the Chilton Manuals [I assume that you know what they are] had more information about model specific stuff. Thanks! I eagerly await your reply. Have a nice day.
Expert:  Jerry replied 1 year ago.

Not sure if that would work on it, but wait there may be another expert who has more. I will opt out and open it back up. Please DON’T REPLY to this post as that will lock the question back to me, also DON’T RATE THE ANSWER yet, someone should be along shortly, I’m sure, thanks and sorry I wasn’t able to help with it.

Expert:  camerontech replied 1 year ago.

hi there,

My name is ***** ***** i think i can helo you with this.

I have included a wiring diagram of the tcc circuit

It looks like a pretty simple 1 wire 12 v circuit. The computer is looking for a 12v signal from a fuse through the tcc. If there is nothing there than it thinks it is engaged.

I dont think i would wire a direct 12v to that circuit as i think it could possible damage the pcm.

Instead, i would wire in a relay, and use the relay as a dummy tcc solenoid. the computer doesnt know what its controlling, it just wants to see power at that circuit and ground its control when it thinks necassary.

so wiring in a relay should do the trick to fool the pcm.

Any other info, please let me know.

I appreciate any positive rating, and always reply to follow up questions with no problem


Expert:  camerontech replied 1 year ago.

for the relay, I would try (on a standard relay) pin 86 12v fused

and pin 85 to your pcm pin.

If it still comes on than swap the relay connections, because the relay might have a diode in it and in that case the pcm wont see the 12v signal.

Just remember to fuse the circuit.

I have included a diargram for you


Expert:  camerontech replied 1 year ago.

hi there, did you get my message?


Expert:  camerontech replied 1 year ago.