NP-231 Fun

[Miles]

Another thing that does not make any sense is that after Mike wired the other two sensors pig tails back in, I plugged their corrosponding sensors into them. Once I did this & drove the Blazer again, the transmission would just go into a *neutral* state after I let off the gas when in 1st gear, LO range.

BUT...when I unplug the two other sensors from their wiring harness, the transmission acts normal in LO range, when you let off the gas! :huh: Could wiring all three plugs together possibly cause the same thing to happen again? Or possibly burn up the VSS sensor that's in the 231 tail shaft?

[HenryJ]

Just read his post. If there is indeed a switch or connection in the encoder motor then, yes you will need to make that connection. I'll take a quick peek at that.

If all it is looking for is VSS readings, that is easy. They are just pulse generators. Give it a matching pulse. Splicing the wires as above will do that.

You are taking one VSS and sending signals as if there were two. They are just not separate.

[Miles]

Here's a couple more pics:





That skid fits CLOSE to the 231! in fact, I fabbed up some 1/8th" spacers to fit in between the cross-members & the skid plate. I even shaved the bottom of the 231 down, so that the little "ears" that were on it would not touch it.

[HenryJ]

Originally posted by Muslhed@Aug 9 2007, 06:22 PM
Another thing that does not make any sense is that after Mike wired the other two sensors pig tails back in, I plugged their corrosponding sensors into them. Once I did this & drove the Blazer again, the transmission would just go into a *neutral* state after I let off the gas when in 1st gear, LO range.

BUT...when I unplug the two other sensors from their wiring harness, the transmission acts normal in LO range, when you let off the gas! :huh: Could wiring all three plugs together possibly cause the same thing to happen again? Or possibly burn up the VSS sensor that's in the 231 tail shaft?

You won't burn up the VSS sensor. It is just a pulse generator. Tapping the two wires together does the same thing. Contact, no contact, and repeat. that is all it does.

I don't know about the "neutral state" , that may be related to the lack of a front shaft signal.

[Miles]

Originally posted by HenryJ@Aug 9 2007, 06:25 PM
Just read his post. If there is indeed a switch or connection in the encoder motor then, yes you will need to make that connection. I'll take a quick peek at that.

If all it is looking for is VSS readings, that is easy. They are just pulse generators. Give it a matching pulse. Splicing the wires as above will do that.

You are taking one VSS and sending signals as if there were two. They are just not separate.

Well, lemme know what you see on that. We can wire all three sensors together pretty easily.

Thanks man!

[Miles]

Originally posted by HenryJ@Aug 9 2007, 06:11 PM
Signal High Front YEL needs to attach to Signal High Rear LT BLU
Signal Low Front PPL needs to attach to Signal Low Rear DK GRN

I hate to say this....and I feel like an idiot.....but ya lost me there! I know that the VSS that's currently in the tail shaft of the 231 has one light green wire with a black stripe, and one purple wire with a white stripe.

[HenryJ]

I don't see anything in the encoder motor. The transfercase shift control module may be another thing though. That may have some control over the shifting?

K.I.S.S.

What does it need to be the same? All the VSS sensors running the same speed is normal, right? We can do that by splicing them all to the one functioning sensor.

Wire the sensors all to the one and give it a try. You have nothing to lose.

If that doesn't work, then the encoder motors operation may be needed. It is a series of four hall effect triggers. Open or closed grounds for four wires and a reference voltage. I really don't know what needs to be done to simulate this function beyond attaching it somewhere. I don't know what the options might be yet. If this is indeed something that needs to be done.

[HenryJ]

Originally posted by Muslhed@Aug 9 2007, 06:36 PM

I hate to say this....and I feel like an idiot.....but ya lost me there! I know that the VSS that's currently in the tail shaft of the 231 has one light green wire with a black stripe, and one purple wire with a white stripe.

Sorry , I keep forgetting we have three to make happy

try this:

Signal High Front YEL needs to attach to Signal High Rear LT BLU and VSS signal high PPL/WHT
Signal Low Front PPL needs to attach to Signal Low Rear DK GRN and VSS signal low LT GRN/WHT

[HenryJ]

I do see the Bravada having a GRY/BLK wire that grounds for the 4WD low signal. This is done via the transfercase shift control module. It might be possible to intercept that wire and ground it so the PCM receives that grounded signal. That might be the switch that is needed if just adding signals for the VSS connections doesn't work.

[Miles]

Bravada?

[HenryJ]

The utility wiring diagrams include some optional wiring. Bravada only was the reference. Or something like that.

Have you wired them together yet? Leave the encoder motor off and try it with just the sensors attached together.

[Miles]

I won't be able to mess with it anymore until Saturday morning. My wife is going to Vegas for work early Saturday morning, and I need to get some quality time in before she leaves. B)

Mike said he would come over Saturday and work his wiring magic with his soldering gun again. \\One other thing that I noticed is that when I manually shifted from 1st to 2nd under part throttle in LO range....it seemed much softer than normal. Mike mentioned something about the line pressure being increased when the PCM knows that it is in 4LO. I get the feeling that it has no clue that the transfer case is in LO range.

I will give this all a run on Saturday, and we'll see what happens.


Soooooo, whaddya think of the install pics? I absolutely LOVE that console!

[HenryJ]

Originally posted by Muslhed@Aug 9 2007, 08:54 PM
whaddya think of the install pics? I absolutely LOVE that console!

Awesome would be an injustice :thumbsup:
It all looks really nice!

[ArkansasBlaZeR2]

Brule I had the same idea last night. It didn't work. In fact the VSS sensor didn't work then either. ??

[HenryJ]

Originally posted by ArkansasBlaZeR2@Aug 9 2007, 09:22 PM
I had the same idea last night. It didn't work. In fact the VSS sensor didn't work then either. ??

Did you connect all the highs and all the lows together correctly?

EDIT: Ok, let us assume you did indeed connect them correctly and it did not work. Here is what you need to try next:
Locate the PCM connector. Find pin #16 with the GRY/BLK wire. This should be the only gray wire with black. There are several plain gray wires. It is in the C2 connector. They are numbered. In the C1 connector 13-16 are not used , so you can't pick the wrong one. This is the 4WD low signal. Attach a wire to a switch and ground it via this switch.
That is what the signal from the TC module does when the encoder motor moves to low range.
See if that works.

[Jigg]

I've got to say, you guys impress me to no end. The amount of knowledge and willingness to try innovative ideas you guys have is mind-boggling.

Keep up the good work!

[ArkansasBlaZeR2]

Well since the cable bracket seems to be non-existent... I fabed something up today. It's damn sure not purdy, an it's extremely temporary, but it's strong and it'll work short term. :thumbsup:

I'm almost ready to rock and roll!

[Miles]

Good deal man!

[F9K9]

Originally posted by Muslhed@Aug 11 2007, 10:28 PM
Good deal man!

Knucklehead!!!!!!!!

[Inced]

got a q for yall, since i am goin to be doin this swap down the road. But mine isnt a autotrac. will i still have this 4low problem?

[HenryJ]

Originally posted by Inced@Aug 12 2007, 07:01 PM
got a q for yall, since i am goin to be doin this swap down the road. But mine isnt a autotrac. will i still have this 4low problem?

Jeremy may have a better idea about the specific differences. You only have one sensor, so the multiple VSS issues will not be a problem.
If in fact the encoder motor position is affecting the transmission shifting, then the likelihood is that you will have the same issues.

I am waiting for someone to get excited about this again and try some more. If it really is as simple as grounding the PCMs low range indicator wire, that would be a piece of cake.



Lets sit back and wait for someone to try it.

[cknaffle]

Originally posted by Inced@Aug 12 2007, 07:01 PM
got a q for yall, since i am goin to be doin this swap down the road. But mine isnt a autotrac. will i still have this 4low problem?

You've got a 5 speed. No.

And if you don't believe that, I'd already done it!

[HenryJ]

Now there is something I didn't consider. The only thing that can cause a shifting problem in the manual transmission is operator error.
I didn't know he had a manual transmission

[Inced]

but when i DO do this swap, i will also be swaping in a auto.

[HenryJ]

Originally posted by Inced@Aug 12 2007, 08:52 PM
but when i DO do this swap, i will also be swaping in a auto.

OK, throw another monkey wrench in the mix! If you plan for it to be a 700R4 that is not electronically shifted, then you should have no problems.
If you plan to import the PCM, TCCM , BCM and associated wiring for a electronically shifted 4L60E or better yet a 4L80E then you have more problems in front of you than just the 4 lo shifting.

[cknaffle]

Originally posted by Inced@Aug 12 2007, 08:52 PM
but when i DO do this swap, i will also be swaping in a auto.

Good luck with that! What a nightmare. As Henry said, I'd stick with a 700R4.

[Inced]

I've been doing alot of reading and searching on the 5speed to auto, so i should be fine with the 4L60E.



Sorry for the topic jack Jeremy

[Miles]

Originally posted by Inced@Aug 13 2007, 03:26 PM
I've been doing alot of reading and searching on the 5speed to auto, so i should be fine with the 4L60E.

David, when my current 4L60-E goes out, I fully intend on replacing it with a massively built, non-electronic 4L60, which is also known as the 700R4. Just have to figure out the kick-down linkage for the throttle body.

There's just too much red tape to go through to get this thing to do what I want it to. I prefer less electronics anyway.....but I loves my automatic tranny! B)

[cknaffle]

Originally posted by Inced@Aug 13 2007, 03:26 PM
I've been doing alot of reading and searching on the 5speed to auto, so i should be fine with the 4L60E.

And the advantage to a 4L60E versus a 700R4 would be what? All you're doing is making the project significantly more complicated.

[Inced]

Originally posted by Jackson+Aug 14 2007, 11:34 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Jackson @ Aug 14 2007, 11:34 AM)</td></tr><tr><td id='QUOTE'>

And the advantage to a 4L60E versus a 700R4 would be what? All you're doing is making the project significantly more complicated.

word.........he obviously needs to do some more reading...... [/b][/quote]
we will see

[HenryJ]

It sounds like it worked!

Originally posted by "stroker01zr2"
Good news guys, grounding the wire works like a charm! The tranny shifts just like it did from the factory and no longer has the "neutral" feel when coasting. very simple fix for those who have switched to a manual t case. What I found out.....

The grey/black wire carries 12v from the pcm to the tccm harness any time the key is on.

Grounding this wire at any time causes an instant change in shift points.

You do no have to stop or even be in low range, however its probably not a good idea to hit the switch while moving and probably a bad idea altogether to do it while in high range. after all, you would have to stop anyway to shift the t case so the best idea would be to only switch then...which is when it would change if it was still in factory configuration.

Removing the wire instantly changes shift points back to normal.

If the switch is flipped while in high range the tranny upshifts at like 1000 rpm and really lugs. while this can't be good at all for the tranny it probably wont break anything if accidentally flipped.

[Miles]

Brule, do you have a link to a thread where this was discussed? I have not heard of anyone else attempting this. Very good to hear though! :thumbsup:

[Miles]

Aw hell! I didn't realize that there was any further discussion in that thread! Very cool!

Now I just have to pretend like I'm not a complete moron.....and try to figure out where this "PCM Connector" is, that's being discussed......



Jerm =

[HenryJ]

http://www.zr2usa.com/mboard/index.php?showtopic=18091

It is your thread on ZR2.com in the Ask Mike Forum.

EDIT: Looks like you already know

[Miles]

Where is the PCM Connector that I need to tap in to? I hate to sound like an idiot....especially if this is common knowledge....and I'm the only one in the dark!
....

[HenryJ]

Bear in mind that I am not doing this so this is not from experience. I am shooting from the hip with some educated information only.

The PCM sits on top of the expansion tank. On the right hand inner fender. Inside the engine compartment.

First you need to remove the PCM from the bracket and retaining clips so that you can see the back side better. Push the metal rod clip toward the AC dryer/filter and gently push back the two plastic retaining hooks while lifting on the PCM. It should slide up and in a little to be loose from the mount.

There are two long flat connections to the PCM. The upper is C1 and the Lower C2.
Locate the C2 PCM connector. Use a small screwdriver to gently pry loose the hooks that retain the gray plastic shield. You do not need to unscrew or unplug anything.
Find pin #16 with the GRY/BLK wire. It is in the lower connector inside (engine side) as it sits mounted on the expansion tank. This should be the only gray wire with black. There are several plain gray wires. They are numbered. In the C1 connector 13-16 are not used , so you can't pick the wrong one. This is the 4WD low signal. Attach a wire to a switch and ground it via this switch.

I would use 16 or 18 ga wire. Carefully cut the insulation around the wire to expose 3/8 to 7/16" of the wire. Strip 1/2" of the end of the wire to be added. Wrap this around the exposed portion of the gray/black wire. Solder the two. Coat with liquid tape and wrap with electrical tape to seal.
Run this wire down below the HVAC housing to the firewall grommet just below the top edge of the carpet inside.



From there take it to a switch that is conveniently located. The switch should be normally open and close when low range operation is desired. One side of the switch from the attachment to the PCM and the other to a good ground.

It can me manually activated, or a micro switch added to the shifter might be a good idea. It could be activated when the lever moves to the low range position. There are many roller micro switches , or even a shifter mount back up alarm switch could be used.

EDIT: Looking at the video it looks like the same wire may be accessed from the encoder motor connector? I would contact stroker01zr2 and find out where the connector is easily accessed.

[Miles]

Thank you Brule! B) We're going to tear into this on Saturday. I'll post up how it worked out!

[HenryJ]

It should not be too difficult to adapt a momentary contact switch to activate it when moved to the low range position. I would be really nice to have it seamless and invisible.

[ArkansasBlaZeR2]

Originally posted by HenryJ@Aug 29 2007, 08:44 PM
It should not be too difficult to adapt a momentary contact switch to activate it when moved to the low range position. I would be really nice to have it seamless and invisible.

In fact, the factory switch on the lever assembly that turns the 4wd lights on and off, would serve perfectly for this...

[HenryJ]

Originally posted by ArkansasBlaZeR2@Aug 29 2007, 08:53 PM
...the factory switch on the lever assembly that turns the 4wd lights on and off, would serve perfectly for this...

Now that really sounds good!