02 ATX to MTX need Help with wiring !

olafurrobert · Post by **olafurrobert** » Sun May 20, 2012 9:59 am

Hi, I just finished swapping out my blown 41te tranny for a t350 manual stick. on my Neon 2.0 2002 model

everything is installed.

but i am having a few issues with wiring,

Can you guys help me????

a) my speedo aint working

b) car wont start, starts if I wire the start relay directly and runs fine , revs to 6800

c) has 2 transmission codes.

,

Is is nessiary to get a MTX pcm , or can i just use my old ATX pcm , since these models had a seperate Tcm ?

I noticed that the car has a 3 wire plug waiting near the speed sensor , can i just plug that or do i need to do some wiring ?

does anyone have a wiring diagram of this model ? i havent found the accurate one

olafur_robert@hotmail.com

NickKo · Post by **NickKo** » Sun May 20, 2012 12:30 pm

YES, I would say that it is NECESSARY to get an MTX PCM !!

Also - I'm assuming you have the 'Sentry' or SKIM (security) feature activated.
If that is the case, you'll have to program the VIN into the replacement MTX PCM.

*IF* you are lucky enough to score a good used 2001-2002 PCM that does NOT have the 'SKIM' feature activated, be sure to unplug and deactivate the SKIM module in the steering column, or else it will instantly "become" a SKIM-activated PCM and you'll have to program the VIN into that one, too.

- Nick

esteinmaier · Post by **esteinmaier** » Sun May 20, 2012 12:34 pm

Your problem lies in the VSS and interstop. Gonna have to wire up those.

Post by **occasional demons** » Sun May 20, 2012 2:08 pm

Possible spare connector for VSS? viewtopic.php?t=62569

Not really sure you need to use an MTX pcm. If it was an '03 to '05, then it would be the better route to take. You need to like Eric said, change the wiring at the range selector switch connector, and wire in the clutch interlock for your starter.

Now the thing that has me wondering is why the ATX pcm allowed the engine to rev past 6000 rpm. Much over that, and torque converters tend to expand inside.

Being separate units, the '02 PCM may have the capability to read the VSS signal from a 31th, or t350 sender. The 41te uses the parking sprag notches to read the output speed of the axles for the speed reading. It will be wired to the TCM, so those wires will not work for a VSS signal.

The only thing is IDK what the pcm is going to do if the TCM is disconnected. Basically they linked for TPS signal to the TCM for up/down shifts, if in gear or not for idle speed/rev limit, etc. If you just set the range sensor to P or N, it will likely start, but the rev limit should be kept to about 3000 rpm. Not a fun drive.

olafurrobert · Post by **olafurrobert** » Sun May 20, 2012 6:00 pm

the signal from the t350 is it send directly to the speedometer or is it going through the pcm first ? if so , does the atx pcm have this option activated,

I figured out the how to get the car going, and is revs to maxinum rpms.

Post by **occasional demons** » Sun May 20, 2012 7:28 pm

The signal goes to the PCM, and TCM on the pre neon cars. Since it is the same basic pcm/tcm configuration, and I don't have an '02 wiring diagram, I would only have to guess they didn't change much as far as the wiring inputs.

The bitch is, even tho export neons had the 41te in '01, the '01 FSM does not provide any info for the 41te.

But yeah, the PCM sends the signal to the cluster via the PCI bus. This started in 2000 model year neons. There isn't any way around it. a 1995 to '00 cluster will not work out too well for all the other functions. You would need to re wire a lot of the engine bay, etc, and use all 1gn sensors where applicable to make the cluster work.

Edit: The thing is, IDK if the signal from the 31th and t350 are the same as the 41te sender. And which unit; pcm or tcm is sending the signal to the cluster. Now, the 41te can be programmed via the DRB tool to change the signal to the cluster for different sized tires on different models. The input for the 41te signal is 8000 pulses per mile. I have not found info for the 3 speed and MTX sensor.

Barry McCockener · Post by **Barry McCockener** » Sun May 20, 2012 8:06 pm

Try these links and see if you can see the diagrams. They're for the '02 ATX.

LINK

LINK

LINK

Edit: username is student
password- watc

olafurrobert · Post by **olafurrobert** » Sun May 20, 2012 8:29 pm

thanks for that, for some reason i can´t log in

Barry McCockener · Post by **Barry McCockener** » Sun May 20, 2012 8:47 pm

Were you able to see the diagrams? Try logging in through here. Same username and pw.
http://search.ebscohost.com/

olafurrobert · Post by **olafurrobert** » Sun May 20, 2012 9:03 pm

no , i cannot log in, sorry

Barry McCockener · Post by **Barry McCockener** » Sun May 20, 2012 9:12 pm

See if you can look at this. It's 3 pdf files with the wiring diagrams.
https://acrobat.com/#w=uZWDG9kb-wcId9Ba-7ideg

olafurrobert · Post by **olafurrobert** » Sun May 20, 2012 9:14 pm

does anyone know this ? is the mtx pcm the same in models 96-04 ?

Post by **occasional demons** » Sun May 20, 2012 10:03 pm

No they are not.

You can only use the MTX pcm from either a '01 or '02 neon. A 2000 would work, but there would be no idle control, and you would have a CEL from the wrong wiring/IAC valve.

And there is also the possibility of a SKIM issue, like Nick mentioned. If you do not have SKIM, then the best bet would be to try for an '01 pcm, as they seem to be less likely to have it. As the cars got newer, they packaged those little "extras" in more often.

Not sure how they optioned the exports to Iceland. Possibly they all have SKIM.

Post by **occasional demons** » Sun May 20, 2012 10:17 pm

Not sure why you cannot log onto the site, unless your locatoin does not allow it.

Anyways, the wire colors match the the MTX colors for the VSS connector. So you may be able to extend, and splice on an MTX connector to the original speed output sensor wiring.

BUT, for what it's worth, that site also shows a TTC solenoid for an R/T model. R/T's do not come with automatics.

olafurrobert · Post by **olafurrobert** » Tue May 22, 2012 8:04 pm

it could be a problem with the region.

i measured the dummy plug, and it has power waiting on in, the question is , where does the signal wire go?

Also I found some remanufactured pcm on ebay.
they offer preprogrammed pcm with matching vin code for the skim system , mine has one.

they are wanting 150$ plus 50$ for shipping , has anyoned tried this ?

any links ? for sites that offer online purchase and download for the 01-02 service manual

thanks for helping

Olav a.k.a the snowman

gilly02le · Post by **gilly02le** » Sun May 27, 2012 8:47 pm

02's will have the plug for an mtx style speedo(3 pin) But no pcm software for it. You need an mtx pcm to get the speedo working. I'm in the same boat.

Need to look at a pin-out for the Transmission range sensor, to verify which pin gets grounded when the car is in park or neutral(as an automatic). Wire that to your clutch pedal switch, and ground the other wire coming from the pedal switch. If i figure out which wire it is, ill let you know, i don't currently have mine wired like that, just a push button start to bypass all of that.

a23dranger · Post by **a23dranger** » Mon May 28, 2012 12:19 pm

On my 02 I swapped in a 00 engine bay harness and ecu along with t.b so the iac works. Had issues getting wiring to work with the auto 4spd 02 harness. Said f that as I had the othr stuff laying around

olafurrobert · Post by **olafurrobert** » Wed May 30, 2012 8:43 pm

Do you guys think I could use one of these to convert vss signal from from the t350, to the atx pcm

http://www.dakotadigital.com/index.cfm/ ... prd126.htm[/url]

Post by **occasional demons** » Wed May 30, 2012 8:47 pm

It may be possible, but I couldn't say for sure. You need to remove the [/url] from your link so it works.

olafurrobert · Post by **olafurrobert** » Wed Jun 06, 2012 11:57 am

Does anyone know where i can find a 01mtx pcm without skim?

Post by **occasional demons** » Wed Jun 06, 2012 3:28 pm

Ebay, or the FS boards on this site, or neons.org. Or pay your life's savings, and get a new one from the dealer. All new PCM's come non SKIM.

If you were going to buy from the dealer, may as well get an R/T pcm. I mean if you're spending that kind of cash...

INVUJerry · Post by **INVUJerry** » Wed Jun 06, 2012 6:02 pm

Chris Hagan got his to run but the speedo didn't work until he got an MTX harness and Ecu.

NickKo · Post by **NickKo** » Sun Jun 10, 2012 4:24 pm

INVUJerry wrote:Chris Hagan got his to run but the speedo didn't work until he got an MTX harness and Ecu.

Now that is interesting.....

- Nick

gilly02le · Post by **gilly02le** » Mon Jun 11, 2012 7:34 pm

To get the car to start with the atx wiring and computer still in, You need to ground the brown/yellow wire running out of the old 10pin atx plug.(the grey one). There are two brown/yellow wires on that same plug, you are looking for the one at the end of the row that's got a blank pin. (last pin(br/yl) on side with 4 wires) White and solid purple are your reverse lights also. Again, speedo is a computer issue, not wiring.

olafurrobert · Post by **olafurrobert** » Fri Jun 22, 2012 6:56 pm

I got the car started the first day, but still having issues with the speedometer, got all my parts for the swap from a 1995 donor,. got the 3.94 trans, every things seems to work , but havent found time to get the speedo working. the workshop is full these days.

have been thinking about mixing together the cluster from the 1995 with the 2002, and add the old pcm only to run the meter,

Got a new idea , maybe i should just get my hands on a 2.4 turbo motor with harness and pcms , arent the Vss signals the same for the t350 and t850 ?

have also been looking for a mtx pcm and harness, how can i recocognise pcm that didnt come with skim, some serial number or just luck ?

Thanks for all the help.

...Olav the viking...

Post by **occasional demons** » Sat Jun 23, 2012 12:38 am

olafurrobert wrote:, how can i recocognise pcm that didnt come with skim, some serial number or just luck ?
.

You would have to ask a dealer to check the VIN# on the PCM.

Unfortunately, there isn't any other way to tell. Other than plugging it in, and seeing if it works.

olafurrobert · Post by **olafurrobert** » Sun Aug 12, 2012 9:09 am

does anyone know where i could buy some parts for my swap. tryied to put in an ad in the forum but didnt work,

what i need is :

wireharness from a mtx car
a Pcm from a mtx
a matching skim module
and maybe the wireles remote for the doors

then i dont need to visit the dealer for programming???
since i live in the middle of nowhere , where every one elses drives a toyota.

NickKo · Post by **NickKo** » Sun Aug 12, 2012 10:19 am

olafurrobert wrote:does anyone know where i could buy some parts for my swap. tryied to put in an ad in the forum but didnt work,

what i need is :

wireharness from a mtx car
a Pcm from a mtx
a matching skim module
and maybe the wireles remote for the doors

then i dont need to visit the dealer for programming???
since i live in the middle of nowhere , where every one elses drives a toyota.

I would keep checking the 'For Sale' boards here.

Occasionally, someone will sell a PCM with matching SKIM key and transponder.
The same goes for the wiring harnesses.

- Nick

Post by **occasional demons** » Sun Aug 12, 2012 12:04 pm

An '01 SE base car would be the best to look for, as SKIM would be more rare on those. (Not that you have much to choose from) I would still check ebay, even if it is from a reman vendor. Most of those are not ridiculously priced, and if you call they may have a non SKIM available. That would save you the cost of the reman PCM just by not having to have it flashed at a dealer.

NickKo · Post by **NickKo** » Sun Aug 12, 2012 1:44 pm

occasional demons wrote:An '01 SE base car would be the best to look for, as SKIM would be more rare on those.

Good idea.

There are non-SKIM 2nd gen Neons out there, these are not common, but they do exist.
( the 2000 in our garage, for example - a base model.)

*IF* you do not have the SKIM / Sentry /Immobilizer on the car already, then swapping over to a non-SKIM PCM, will be easy.

My guess is, that your 2nd gen has the SKIM module, since it appears that all the 'export' models had them.

* You might be able to swap over to a Non-SKIM PCM, but you will have to remove your immobilizer / SKIM module, before starting the car, to make it work.

* (Bill..... If I am missing anything, please let us know !! )

- Nick