2JZGTE swap this summer...

A member on Jeepforum also gave me this. Similar thing, just different chip, and different methodology, yes?

025tx7ic.jpg

0RadioShack_TL082_TL082CP97227.jpg


Kastein, regarding the "input 1- or 2-: 1k ohm resistor to 5V VSS power, also 3.9k ohm resistor to GND"...

is that just tapped in to 5v vss power and then split off to the 3.9k ohm resistor to ground?
 
I'm not sure why you'd bother with that much complexity, but it could work. That appears to be a difference amplifier circuit feeding a non-inverting amplifier circuit. You can do it that way but it's overcomplicating things, all this needs is a simple level comparator setup.

Lemme draw it out, will update this post.

xeqz5i.jpg
 
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I thought that was more complicated than this required, which is why I wanted you to look at it. :)

I have a dedicated 5v output from the ecu for TPS and MAP sensors.

I'm hoping to start sourcing components tomorrow.
 
Lm741 is designed for dual supply rail (+12 and -12 volt supplies) iirc but should be fine in a comparator app such as this. I am not sure its output swing is large enough compared to supply voltage though. I would go with the tl082.

I'm surprised they don't stock the lm324, which would be ideal for this.
 
Flip-flop will divide the frequency by two. If that works out right for the tire size and gearing, go for it... but unless you get a flip-flop with some pretty laid back input level thresholds it won't condition the signal any better and you'll have to use the comparator with it.
 
Actually, I don't know. My best friend works at a particle physics lab @ UT, so he's hooking it up. He is pretty sure it's of the ferric variety, but not 100% sure.

As I understand they are changing the circuit. Something about while opamps can do the task, transistors can do it much faster, with more temperature resilience, and are cheaper. I'll know when I get the new schematics.
 
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Chad,
Just make sure you end up with a square wave output. In a pinch, you could always clean the signal by running it through an AND gate. Tie the inputs together.
 
Checked and double checked.

I'm off today, so I'm gonna head down and wire the Jeep side of things in preparation for the circuit board completion.
 
It appears that the ECU will still read the 5v signal after all, despite it's expecting 12v. I'm still going to use the amp and see if that helps, but now I suspect a frequency problem. Jeep is shifting, but shifting way to soon, is staying in higher gears more and doesn't want to release the lock-up converter. I think the compy thinks I'm going faster than I am...but I am not yet sure.

Does anyone happen to know with a high degree of certainty what ppm (pulses per mile) or pulses per revolution the Jeep VSS#2 in the transfer case is?


SprintPhoto_c0pylf.jpg


SprintPhoto_b0pylf.jpg


Does anyone have a spare gauge coolant temp sensor plug lying around? I'm going to plug in the Jeep gauge sensor into the Toyota water neck.

SprintPhoto_b44qvt.jpg
 
Okay I see you said three wire so hall effect type. For hall effect type the Jeep PCM supplies 8V into sensor which then outputs 5V square wave. Since you don't use Jeep PCM where are you getting 8V supply for VSS?

You said the Toyota ECU expects 12V? What is the Toyota VSS supply voltage? If it's also 12V you could replace the VSS with a two wire type. Yes it will handle 12V at low current. I did a swap where I ran 8V thru a two wire VSS and added a pull down circuit to the output to get 5V. Works perfectly.

Last thing coming to mind is Toyotas (some anyway) look for two independant VSS signals to control trans shifting. That could be related to your shifting issues.
 
As of now I have supplied 5v sensor power from the Toyota ECM to the Jeep VSS #2 power in.

Toyota VSS supply is technically unknown, but since it outputs a 4 pulse 12v signal and the vss supply voltage is not coming from the ecu, I'm very sure it is getting 12v supply to start with.

From all of my documentation, the extra vss signal is used only as a back up, or in this case, the primary signal.

I also swapped out the Toyota CTS to gauge with the Jeep sensor. Both sensors shared the same thread size and pitch. I should have accurate temp readings in the dash panel now.

What kind of chip or component will allow me to build a manual shifter using either two buttons or paddles to shift the gearbox sequentially? I imagine some sort of logic gate, but the key is the "sequential" part. Kastein, O-gauge...any ideas?
 
What do you have for shift solenoids on the a340 valve body? I only know the aw4 well, don't know anything about the a340. If it is the same setup I can throw together a design for you either later today or sometime tomorrow, should be pretty simple.
 
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