1JZ vvti speed sensor on auto

[Wizzard]

Hi guys,

Not sure if you will know as its Soarer specific. I am putting a 1JZ vvti into my Soarer (91 model). The regular 1JZ has a speed sensor at the back of the auto which goes to the Soarer dash (to the speedo) and then that comes back to the ecu as SP1.

On the vvti auto this speed sensor no longer exists, the two wires that go to the combination meter are missing. So I am guessing I will have no speedo readout. The funny thing is that this is a 1JZ vvti from a Soarer, and therefore must have some info that can go to the dash.

There is a SP1 from combination meter on the ECU just like the original one, but not sure how the combin meter (speedo) gets the speed signal anymore.

Can anybody help?

Justin.

[wilbo666]

I've never seen wiring diagrams for JZZ30 VVTi 1JZ, but I can tell you how it works on JZA80 VVTi 2JZGTE


On JZA80 VVTi 2JZGTE (auto) there is no dedicated speed sensor for the dash (sounds the same as your VVTi 1JZ), instead the SP1 signal on the engine ECU goes to the dash!

So it goes, 2 wire reluctance sensor (rear of auto, passenger side) -> engine ECU -> SP1 output to dash.


Perhaps this is also how yours needs to be arranged?

Cheers
Wilbo

[Wizzard]

Ah Wilbo, they should just give you 1000000 rep and be done with it Won't let me rep you cause it seems your the only one I rep hahaha.

Ok, that makes a heap of sense then, only thing that was really really making me scratch my head was the pin diagrams found around.

Plug C86 - 28 PIN
Speed signal from comb. meter SP1 12 P

So I am guessing this should actually be TO comb. meter.

So next question Wilbo, There are two wires usually going from the speed sensor to the comb. plug on a blue and pinky one. There is only one SP1 out of the ecu. I obviously need to wire the blue or pink to the comb. meter, does the other one go to earth?

[wilbo666]

So next question Wilbo, There are two wires usually going from the speed sensor to the comb. plug on a blue and pinky one. There is only one SP1 out of the ecu. I obviously need to wire the blue or pink to the comb. meter, does the other one go to earth?

Normal 3 wire dedicated speed sensor has 3 wires,
Power (+12V from gauge fuse)
Ground
Signal (+12V square wave output to dash)

I think you'll find the two wires are Power and Signal...

If that is the case then just leave the Power (from the gauge fuse) disconnected / unused

Cheers
Wilbo

[Wizzard]

Looking at the wiring diagrams, yellow is 12 volt (not of the two wires), seems Red is ground. Blue-red is the signal from the box. I am totally looking at this wiring diagram and I have no idea how they changed the combi meter for the vvti soarer. It shows that the plug is not used in the automatic after 97.8 but on the combi meter it still has the wires required.

[wilbo666]

Combi meter / dash doesn't change at all.

Connect the blue-red wire to SP1 on the VVTi engine ECU

Cheers
Wilbo

[Wizzard]

Red one to ground?

[Wizzard]

Looks like it needs to be grounded for some other functions in my combi to work

Ok cool. Thanks heaps.

[Wizzard]

Hey Wilbo, small problem, 1JZ is in. Looking through the pinouts again, there is NO pin to combi for speed on the pinouts. The PIN 12 on the 28 pin plug that says SP1 from combi meter. That wire just plain doesn't exist (its a blank).

I am so confused as to how the dash gets the speed now.....Totally at a loss.

[wilbo666]

In most normal toyotas it goes

Speeds sensor on gbox (dedicated for dash) -> Dash -> SP1 to engine ECU (From Dash)



Your setup will need to be (I suspect)
Speed sensor on gbox (2 wire for engine ECU) -> SPD to Dash (From engine ECU)



SP1 is an output from the dash to the engine ECU, if you have the VVTi setup then this isn't used.

Email me the digrams you have (I'll send you a PM with my email addy).

Cheers
Wilbo

[pales]

Hey Wilbo, I sent you a PM about this... what was the outcome from this thread? I have the same issue.

Cheers Mike

[Wizzard]

Hey Mike,

I figured it out eventually with Wilbo's help. On a VVTi motor the one speed sensor from box does the speed to the ecu. The rest of the car I have figured out gets its speed from the wheel sensors and sends to dash, power steering, cruise etc.

You have to make an electronic speedo corrector and tap into the speed sensor from the auto (or manual) and send to the rest of your instruments.

J.

[pales]

Hey mate,
Thanks for the reply. Do you have any more info on how you went about this?

Cheers Mike

[midnight_purple_GA70]

well there you go... disregard my ideas via PM thismorning as this confirms vvti is different to non vvti auto

[pales]

haha, nah mate, they are still good ideas... I will compare the two speed sensors and go from there. I think what this thread confirmed for me is that VVTI doesnt send a signal from the dash back to the ecu... ill go with my plan of tracing wires from the sensor and see where that leads me.