mx83 1jz auto issue

[jeffro]

I have just completed a 1jz from jzx81 into my mx83 grande. I have everything working but my od light flashes, got codes out and is speed sensor 2 code 61. Have done heaps research most people have said they just live with it cause it doesnt affect the auto but its really starting to tick me off. Has anyone been able to find what the problem is? If any one has any info like what pin in computer is for this sensor and what sensor it is because i know there is 2 sensors on my gearbox and one is for speedo the other is abs sensor, so where is the sp2 sensor. Any help is greatly appreciated

[slide86]

im pretty sure that there is an issue with the speed sensors in this conversion. apparently the ABS module reads the speed sensor and affects the way the trans shifts. I think it can also prevent it from going into top gear all together!

I read that disconnecting the ABS unit will fix the problem....does your car still have active ABS? if its not working then you can disconnect the module and it should be good.

check this out, should be able to help you
http://www.toymods.net/forums/showthread.php?t=4419

[Hibba]

Alot of people have this code with the conversion, the car will still drive and change gears fine.

SP2 is the big boxy looking sensor on the extension housing.

[jeffro]

Thanks guys, my auto shifts fine and i have got my abs working also, the only thing is this stupid od light. I was hoping someone had figured out why it does it.

[Hibba]

I think its related to the way the ABS worked in a JZX81, because insted of just using a gearbox sensor for the rear wheels the jzx81 had a sensor on each rear wheel.

[SL666]

it *COULD* be because one of the sensors goes to the dash and then gets changed and back to the ECU (thats what a soarer does) perhaps they do a simular thing on the mx, but from the ABS?

[jeffro]

I have worked out that the signal comes from speed sensor 2 on the gearbox then goes to the abs computer. The abs computer then outputs to the EFI computer. Was wondering if anyone had worked out how to simulate this signal.

[SL666]

if its the same as the dash version it just divides it my a bit..

[Mr DOHC]

very interested in this thread, as mine does the same thing, apparently sideshow has yet to even work out how to stop it

[ZZT231]

Try this... I've tried, but my car hasn't been able to leave the drive way...
http://forums.toymods.org.au/index.p..._view=&start=0

[jeffro]

Thanks guys, ill let you know how i go. Does anyone have a complete running jzx81 so i can measure the speed sensor output from the abs computer. I have searched everywhere and cant find much info on the jzx81 any sites you guys know about would be very helpfull, or does anyone have factory service manual.

[Mos]

Hi,
The ABS in both the JZX81 and MX83 has a single speed sensor on the back of the gearbox (3pin, right next to the vehicle speed sensor, also 3pin on the speedo cable output). This signal is a 10V square wave of 32 pulses per rev of tailshaft. This signal is fed to the ABS ECU in the boot. The ABS ECU divides this signal and feeds it back to the engine ECU on pin SP2+, with SP2- being grounded by the gearbox loom (IIR the pin designations correctly). This signal is also a square wave.

The unfortunate part is that the MX83 and the JZX81 divide this signal by a different amount before feeding it back to the engine ECU. If you hook up the JXZ81 engine ECU to the SP2 output of the MX83 the gearbox will not change out of first gear until some ridiculous speed - like 80km/h.

If I were to guess the JZX81 ECU expects 4 pulses per rev and the MX83 uses a single pulse per rev. This is something I have yet to confirm.

An MX83 without ABS has a 2pin sensor that feeds straight into the SP2+ and SP2- pins of the ECU (IIR the pin designations correctly). This signal on other cars is 4 pulses per revolution of output shaft - never looked at the signal from the MX83. Second hand info from a very reliable source suggests his signal is a single pulse per rev but I have never confirmed this.
(Hence the guess on the 4:1 ratio of JZX81:MX83 and the first gear shift speed).


IF YOU DO NOT have the SP2 signal hooked up, the engine ECU defaults to the vehicle speed sensor, SPD. This signal comes from the other 3 pin speed sensor on the extension housing of the gearbox - where normally a speedo cable would go in. This signal is fed to the instrument cluster and the fed to the SPD pin of the ECU. This is the signal that provides speed limiting.

The transmission ECU appear to operate correctly when supplied only with the SPD signal and no SP2 signal. Toyota literature suggests this is a failsafe that does not compromise function.

In addition, older cars, such as the M/GZ20, have a 20 pulse per rev vehicle speed sensor which is divided by 5 in the cluster to produce the required 4 pulses per rev for the SPD input to the engine ECU.

If there is enough interest, an interface box can be developed that divides this ABS signal to the required number of pulses to feed the SP2 signal.
Given there is no operational advantage to have this signal present, such an interface has never been pursued, however as stated I can be persuaded to develop it

PS. Just read the thread started by GT. The non-ABS 2pin speed sensor discussed above is different to the single wire photo posted by GT - it is a 2 pin inductive pickup with a chopper wheel with no magnets (might get some time to dig up the parts and take photos).

HTH.
Mos.

[Mr DOHC]

i may be interested in the siganl box, let us know the details {$$$$}

[PlacentaJuan]

the od light flashed on my 1jz mx73 too, there was never a problem, but i sometimes wondered how i would know if there was a REAL problem with the gearbox, given that the 'problem with your gearbox' light is allready flashing?

[MacroP]

Hi,

An MX83 without ABS has a 2pin sensor that feeds straight into the SP2+ and SP2- pins of the ECU (IIR the pin designations correctly). This signal on other cars is 4 pulses per revolution of output shaft - never looked at the signal from the MX83. Second hand info from a very reliable source suggests his signal is a single pulse per rev but I have never confirmed this.
(Hence the guess on the 4:1 ratio of JZX81:MX83 and the first gear shift speed).


IF YOU DO NOT have the SP2 signal hooked up, the engine ECU defaults to the vehicle speed sensor, SPD. This signal comes from the other 3 pin speed sensor on the extension housing of the gearbox - where normally a speedo cable would go in. This signal is fed to the instrument cluster and the fed to the SPD pin of the ECU. This is the signal that provides speed limiting.

The transmission ECU appear to operate correctly when supplied only with the SPD signal and no SP2 signal. Toyota literature suggests this is a failsafe that does not compromise function.

In addition, older cars, such as the M/GZ20, have a 20 pulse per rev vehicle speed sensor which is divided by 5 in the cluster to produce the required 4 pulses per rev for the SPD input to the engine ECU.

Mos.

Great post dude,
The MX83 without ABS has a simple 1 pulse per rev two wire sensor for SP2. It's simply a reed switch and a magnet that impregnated into the rotor.
I guess if a Series 2 MX83(which had non-ABS and ABS models) use the same engine computer(which I'm sure they do) then I might be safe to say that the MX83 ABS divedes this signal by a factor of 32 and sends it to the MX83 engine ECU.

Jaycar make a kit(KC5380) to modify speedo signals up and down(% change) that should work. It's a matter of knowing what the JZ ECU wants to see, maybe 4 pulses per rev(for example) ie get the kit to multiply the MX83 ABS signal up by a factor of 4 or intecept the ABS sensor(SP2) signal and divided this by 8 and send this to the new JZ ECU.