Q about Toyota gearbox electronic speed sender

[KinLoud]

The ST206 Curren I got my 3sge out of had an electronic sender to give the speed info to the speedo.
What sort of signal does it send?
- square wave/sine wave?
- 5 volts/12 volts
- or is it just a reed switch i.e. switched to earth.

I need to know what sort of signal the computer is expecting... trying to anticipate any problems once the gen 3 3sge is in my 1983 Carina race car. Using the factory 3sge computer.

Ken
Hamilton
021 408 863

[KinLoud]

I looked here but it doesn't say what type of sensor was in the curren.
www.autoshop101.com/forms/h36.pdf

Ken
Ham
021 408 863

[RomanV]

There is a guy on MR2OC, 'Lander'. Who has a redtop 3sge in his 1990 SW20. Since the early SW20 had a speedo cable, and the redtop gearbox had a digital speed sensor, he simply replaced the digital speed sensor with the analogue one from his old gbox. Apparently this caused no problems, I believe he was running the stock computer.

Although that doesnt answer your question.

You are wondering if the ECU uses the speed sensor data for any reason, rather than how to rig up a speedo, correct?

In that case, I am of no assistance. I am wondering this myself, as I will be encountering this same problem in the future.

[celica_tommo]

hmmmm.... toyota service manual for my celica (st-182) says 5 volts four times per each revolution. Thats for the S-53 and the E series GT4 gearboxes anyway. Could well be different though given that the E-56 speeed sensor plugged into the side of your gearbox rather than the top as is does with my S-53.

btw Kinlouds Curren gearbox was an E-56

[fivebob]

All the 3S ECU's I've seen get the signal (4 Pulse,0-5v) from the speedo not from the gearbox sensor, so you could run a mechnical speedo from something like a SW20, ST185 etc and get the signal from there (provided you don't exceed 180km/h). Or just use a signal generator if you don't want to use a speedo.

[KinLoud]

Thanks for all the replies.
Yeah - I don't want it for speedo. I want to avoid "check engine" light putting the computer into limp mode while I am racing.
Pulses seem to say it might be reed switch but I dont think the computer will care too much if it is square wave or something similar as it will take its trigger from the voltage drop point (or rise point).
I figure that if I hitch up a reed switch to only give 2 pulses per axle revolution the speed limited won't kick in till 360kph??? Might get this speed if I was driving down a cliff!

Ken
Ham
021 408 863

[RomanV]

Im just curious, but...

Why does the ECU need an input for the vehicle speed? I understand that it uses it for the 180kph speed limiter, but anything else?

Also, I believe that NZ new cars do not come with the 180kph speed limiter that japanese cars are required to have. Is this a software change to the ECU? What I mean is, would the speed limiter be removed if you swapped your japanese ECU with an identical one from an NZ new car?

[KinLoud]

Good question.
I know that my old 4age bigport gave me a check engine light when I raced it without the speedo working, the engine ran just the same as normal so I never worried about it.
I'm just trying to have a solution ready to go if the 3sge computer goes into limp mode if see the revs high but no car speed.

Ken
Ham
021 408 863

[Corona]

When I did my swap, I still havenet hooked up the speed sensor, that car has been working fine so far, but havent taken it to top speed, too many cops around with my luck