After techincal speed sensor informatio

[zolpix]

Hi everyone, i would like to know how a Toyota speed sensor works. I have an idea, using a micro controller i want to create a speed signal. If a Toyota speed sensor sends a voltage based on speed i can convert that voltage to whatever i want using software programing into a microchip. I have a 2JZ-GTE VVTI motor that i will be working with but if all Toyota speed sensors use the same logic, maybe i can create a solution to missing speed sensors from motors we want to use in our vehicles. Basically right now this is an idea, nothing has been tested, but im sure it could work. Please understand that i am working on multiple projects, one of which involves data-logging voltages and a windows program to modify the micro controller from the data. (self learning). So this would be a slow process...kinda like my engine swap haha. But hopefully i can create a controller that is cheap and easy to mimic a speed signal from a foreign enigne. Has this been attempted before? Any information at this stage would be greatly appreciated. Also if all successful, this will be open source i.e free for anyone to make and use.

Thanks in advance

Andrew

[dumbass]

its a square wav pulse with a pull up resistor internally in the sensor
so im sure instead of going from 0 to 7 or 8 v it goes from 12 v down to 3 or 4v
thats for the common speedometer speed sensor
the late 2j vvti doesnt have a speedometer speed sensor
it does have the 2 wire inductive or sine wave sensor on back of box
which is for the auto side of things
how r u going to make it variable as u go faster
if u just want certain constant pulse thats piss easy
just make an oscilator
i find it easier to join the speed in to the injector pulse

[George]

Why the hell do ever want this kinda signal into ECU? Unless you have to run auto g/box it's worthless effort.

p/s some experimental data. I once tried to fool a toyota ECT speed channel (pins SP2+, SP2-). Found that 12v square wave source with 100 Ohm series resistor work ok (so there's no #42 error code and transmission shifts according to my simulated signal)

Real sensor will never output a voltage that high (it only outputs some 4-5v peak to peak sine) but at the time of the experiment I didn't have another signal source handy.

Though that was not exactly 2jz-gte I believe result won't be different with any toyota ecu/ect which runs the same type of speed sensor

[wilbo666]

Hi Andrew, you might want to add the back ground of what you are trying to achieve... :-)

I'm assuming that you're carrying on from this thread...
http://www.toymods.org.au/forums/tec...ed-sensor.html

To summarize as I see it,
-2JZGTE VVTi engine from a JZS161 into a GA70
-The 2JZGTE VVTI from the JZS161 was auto (they only came as auto ), but you're running a W58 in the GA70
-You want to developing a circuit to generate the JZS161 2JZGTE VVTi speed signal to the 2JZGTE VVTi JZS161 engine ECU from the GA70 dash speed signal.


The following should give you the run down on Toyota Speed Sensors
http://www.autoshop101.com/forms/h36.pdf

To summarize the different types of electronic speed sensors mounted on gearboxes,
-3 wire: This type of speed sensor has three wires, one for power (+12V), one for ground (0V), and one for the signal output. The output signal is a Square wave (0V to 12V) output. There are two main types, one outputs 4 digital pulses per revolution of the sensor and the other outputs 20 pulses per revolution. 4 pulses per revolution is more common in my experience.

-2 wire: This speed sensor is similar to a camshaft position sensor or a crank position sensor. An AC voltage signal is generated between the two wires as a tooth passes the sensor.
Usually the zero crossing of the AC signal is used to generate a square wave inside the engine ECU... e.g. see here for some more detail Distributor Pickups


And to summarize the original speed sensors setups
JZS161:
-2 wire speed sensor on rear of auto gearbox (12 of AC pulses per gearbox output shaft revolution) -> engine ECU
-Engine ECU -> signal to dash

GA70:
-speedo cable from gearbox to dash (I have a feeling the dash is 637rev/km, that is 637 revolutions of the gearbox cable gives one km on the dash)
-dash outputs a 4 pulse / revolution digital speed signal to the engine ECU




From the above info (and / or measurement) you should be able to work out what you need to send to the JZS161 Engine ECU and how to get it from the GA70 dash seed signal


FYI I have done exactly what you are trying to do in the past

While I did mention above that 2 wire reluctor sensors usually use the zero crossing of the AC voltage signal to generate a square wave voltage internal to the engine ECU, I have used/inputted a 0V to 5V square wave in the past (Fed to the engine ECU SP2+ pin) and that worked for me on JZS161 & JZA80 2JZGTE VVTi engine ECUs.

This makes the circuit you need to generate the signal much easier (Don't need a zero crossing)



Good luck

Cheers
Wilbo

[zolpix]

Thanks wilbo, great info. What i am attempting to do is use a micro controller for a few tasks, i would like to read cel codes from a lcd display in the cabin, run a few circuits to remove codes for missing items i.e automatic gearbox ect... i seen your jza80 thread where you eliminated codes. It may seem pointless but it is more of a side project to see if i can do it. I want the speed signal for part of my data logging i plan to do (also no real need for this) and also progressive power steering. Cheers

[dumbass]

hey wilbo
did u see if the 2j vvti has a speed signal input
or is it a speed signal output
i remember we had a chat bout this one the other thread where the guy
could not get his 2j working properly

[wilbo666]

hey wilbo
did u see if the 2j vvti has a speed signal input
or is it a speed signal output
i remember we had a chat bout this one the other thread where the guy
could not get his 2j working properly

I haven't really looked at it to be honest....

But this is what you said...

just checked my books
pin 25 which on yr diags is called spd and looks liek it does have speed sensor
somewhere and sends signal to dash and ecu at same time

my diags that pin is called rfc

and there is also pin rfc2
not sure where they go as has bad explaination
but voltages on that pin says it changes when a/c is on

I'm a bit confused as to which pin 25 you say I have labelled as "spd" on my diags?

There are only two 25+ pin plugs (not counting the later model plug that was added), and on the first plug pin 25 is IGF... on the second plug (90980-11637) I have pin 25 labelled as "REC" which from my notes is related to the hydro cooling fan (as is REC2)... if it's related to the hydro cooling fan as my notes suggest that would explain why it changes when the AC is On/Off

My personal thoughts / understanding is that in the JZS161 2JZGTE VVTi system the vech speed is sent over the Multiplex network from the engine ECU to the dash, but like I said I don't have any firm proof of this. Going off the fact that I'm unaware of an output pin from the Engine ECU to the dash for speed in the JZS161 arrangement tho it seems like a fair bet to me

Cheers
Wilbo