MX83 1JZ R154 speedo problem. HELP!

[Cressid@]

Hopefully someone can point me in some directions to fix my speedo problem.

I have a cressida Grande 92 converted 1JZ from Jzx81 and R154 g/b.
Recently my speedo become intermittent, sometimes the needle just drops and goes up a couple times then it ran fine. One day it decided to stop working at all.

I have eliminated a few things.
It is not the speedometer, because I bought another one and it is still not working.
I stick a multimeter into the Speed sensor pin on the ECU and I didnt get no voltages.

So I asume there is no signals at all to the cluster or the ECU.

That leaves the speed sensor on the R154 g/b or the wiring somewhere along the gearbox to the firewall being fault.

My question is, how likely is the speed sensor on the gearbox faulty? how expensive to replace? or can you even get them?
I would love to take it out and examine it but it will requires draining all my oil.

I suspect it is the wiring fault somewhere because it seem like a bad connection somewhere that caused the speedo to drop up and down. Any ideas where can I start looking or diagnose next?

cheers,

[Cressid@]

Sample R154 box



It has 2 plugs on the R154, can someone confirm which plug is the speedsensor? Is it the one circled Green? and what plug is the one circled in RED?

I did more diagnosis, but unsure if it is the correct way? I stick a multimeter on the plug circled GREEN ( i am assuming that it is the speed sensor it has 3 wires; red, white, black). wth the engine runing in 1ST gear, I didnt get any voltages. Is that a good way to tell if the sensor is working or faulty?

I am pretty sure it is not caused by shorted/faulty wiring. (tested for continouity). So it left me with the speed sensor being the culprit????

any inputs? I am keen to fix my speedo problem. THANKS>

Cheers,

[jzx81mx83]

the speed sensor is the one that is circled GREEN and mine was wired up and works fine im pritty sure you can use the one of your auto if not i have one

[Cressid@]

That is good to hear thanks.
From an auto box off 1JZ or cressida 7M auto box work as well?
How much do you want for it? I might need to buy it and test if that is the caused of my problem!
cheers,

[takai]

7M auto box one will do fine. The red circled plug is the reverse lights.

[mumblezzz]

I lost my auto one so i used one from a 20v 4age box.

[Cressid@]

i have a sensor from cressida mx83 GLX, but it is not the correct one.
the one in my R154 is this one below
My guess is have to be series 2 because it is an electronic sensor. Will have a look out for s2 mx83. But definately not series 1 cressida.

[takai]

Ah, i thoguht your R154 had a mechanical output as in the first picture you posted.

[TheDarkRaver]

Are you running a speedo convertor (I.e so your speedo shows the correct speed)?? There could be something wrong with that also..

[Cressid@]

No speedo convertor.

I found the problem, the teeth on the sensor gear are fcked. In the process of looking for replacement gear.

cheers,

[Cressid@]

Thanks to Fiver. Gave me the sensor free!
I will replace the gear tommorow and see how it goes.

Cheers,