[PlanetDude]

Hey all, new to the forum and trying to get my NB on the road. Failed Ontario emission test (OBDII plug in test) because of a bad transmission input speed sensor. Swapped that out. Shifts a little rough but managable for now.

Throwing code P0753 and P1778 now, but only when I stop, or when I park the car and drive it again. If I get cruising and clear the codes it is fine, they don`t come back.

Anyone have any idea where to start with this thing? I don`t want to start throwing money at it, as I don`t have much to throw...

Thanks,
Ryan

 

[Smileybug]

Looks like they point to shift solenoids.

What year car/what auto trans do you have (4 speed, 6 speed, etc)?

 

[PlanetDude]

Sorry, rookie mistake.

98 NB, 2.0 gas, 4 speed auto.

 

[PlanetDude]

Update - it will drive but stays in second unless I clear the code. Then it shifts fine until I come to a stop or slow down, at which point it won't come out of second again. Seems purely electrical to me. And the code p0753 iis for shift solenoid a - could that be all my problem?

 

[jfoj]

Could be the solenoids, could the the wiring/terminal connections, could the valve body, could be combination of many of these??

The solenoids do wear and have problems, also the solenoid connectors are very small and fragile.

Depending on where you live you could have a shop look at the car, you could also remove the valve body and ship it out for reworking.

Many of these valve bodies wear out prematurely and need to be reworked along with the solenoids.

 

[PlanetDude]

Local VW dealer was feeling generous and scanned the car for me. Code of N94 and N88.

Also apparently I have a DMD trans.

Dealer says valve body assy and that the solenoids can't be ordered sepertely. Priced me the valve body at $750 though. With some of the prices I have seen I didn't think that was terrible.

Thoughts?

 

[jfoj]

You likely can get a re-manufactured valve body for $400-$450?? Usually these include reworked solenoids as well.

The valve body is pretty easy to swap if you plan on doing the work.

So it kind of depends if you can do the work yourself and can either ship your valve body or buy an exchange valve body.

Where are you located??

 

[billymade]

I don't know if you are a do it yourself-er or a techie type of person but there is allot of good tech info about the 01M here:

He offers valve body rebuilding among other things; check under "services":

O1M FAQ - Kansas City TDI

You can at least see if you are up to swapping the valve body yourself; check out his diy: http://kansascitytdi.com/01m-valve-body-removal-and-reinstalation/

You might email or call him and see what he says; getting it correctly diagnosed seems to be the main challenge with transmission issues.

 

[PlanetDude]

I'm located in Chatham, ON. About an hour or so from Detroit.

I still need to check wiring, connections etc. I'm also trying to see what my options are locally. We do t really have any good independent trans shops here, but I do have one good independent shop that specializes in imports. Will post back with more info. Thanks for the help!

 

[jfoj]

Be careful, most trans shops will not just replace the valve body, they almost always want to perform a full overhaul.

 

[PlanetDude]

So still no luck. The thing shifts fine if I keep clearing the codes as they pop up. But as soon as I slow down it throws a code again.

Is it possible to trick the computer into seeing the proper signal? All wiring looks ok and all signs point to solenoids. But if I pull the valve body for solenoids, then I might as well replace... And soon I'm at $750 plus on a car I don't have registered yet.

If its possible to trick the computer please let me know! Even so I can get it registered. Or does anyone know of reasonably priced solenoids?

 

[jfoj]

You have a problem, no tricking is going to work.

Please describe your exact codes and what happens.

Also how do you know the wiring is good? Did you pill the trans pan? Its only 6-7 bolts. The wiring is very delicate and the solenoids do wear.

 

[PlanetDude]

Major code is p1778 and that comes up as soon as the car is started. If I drive the car stays in second (fail safe) but if I clear the code using my scanner the car will shift normally. This lasts until I slow down, whic re-triggers the fault code.

I haven't dropped the pan yet. I'm at the make or break point - is it even worth to fix? Also I'm worried about the snowball effect - what might start as a solenoid replacement might end with a total trans rebuild. I was hoping to bypass the solenoids for now at least until I get a feel for the rest of the car.

At this point I either have to commit to fixing it or dump it. And on a 15 year old car with tons of mileage it's a tough call.

Thoughts?

 

[jfoj]

Here is what I would do, get a clean container and drain the trans fluid into from the pan and drop the pan.

You can reuse the pan gasket without much problem and you can reuse the fluid if you run it though a paint strainer you can likely get for free at a home, hardware or paint store.

The trick it you NEED to search my signature for how you fill the trans from the fill plug.

Once you drop the pan, you can check the magnets for metal and see how much trash is in the pan. If the magnets look like Chia pets, time to move on, if there is just a small amount of metal, this is normal. Take pictures.

Then search and figure out what solenoid the problem is with. Make sure the wiring connector is tight, you may need to pinch the terminal to make it a bit tighter.

You can also check the coil resistance, but many times the coils can short or open, but sometimes they are temperature dependent when the problems pop up.

Not sure you can change any of the solenoids without dropping the valve body?

I have worked with a good shop in California that will rework your valve body or they might sell you a new solenoid.

Also sometimes the wiring harness get pinched or damaged inside the trans as well.

You will need to do a lot of research before you want to move forward.

What trans model?? How many speeds?

Again, many of the valve bodies, solenoids and wiring hardness have issues!

 

[Smileybug]

OP posted its a '98 4-speed, so its the wonderful O1M.

I don't think you can "bypass" the solenoids. You need to fix the problem.

 

[PlanetDude]

Well, car is sitting at the best import shop in town waiting for its turn. I'll post the diagnosis once I have it.

I can do brakes and belts and tuneups, but the insides of transmissions are a little over my head.

 

[PlanetDude]

Just got word from the shop - wiring harness to valve body! I haven't picked it up yet but the shop owner test drove it and gave it the all clear.

Ill let everyone know how it is once I have it back!