Toyota speed input supralink

[matt gray]

HI guys,

Issue with JZA80 supra with plugin ecu and r154 with speed sensor. Car was in storage for a couple years and recently back up running but I noticed that the ECU is now not receiving or reading a speed signal.

It does have a new speed sensor fitted and I did have to extend the wires going to the sensor. The odd thing is the dash speedo still works fine. My understanding is this sensor feeds into the dash and then to the ecu. I thought it maybe the wiring from dash to ecu so ran a wire from the dash input direct to the ecu but no change.

I have attached pic of the settings.

 

They do have common fault where the dash has another speed sensor in it which usually fails and you splice the wire input from the sensor to the output to clear the dash fault and enables the signal to the ecu. I had to do this about 9 years ago and never had any issues since.

 

Cheers

Matt

[Adamw]

I would expect the speedo has a built-in pull-up if it was originally designed for a hall effect sensor, but does turning on the pull-up make any difference?  

If that is not the problem then can you put a volt meter on the signal wire going to the ecu (other probe on gound) and either rotate a rear wheel slowly by hand or pull the sensor out and rotate slowly by hand, and tell us what the 2 voltages shown are.  It should step from something close to zero volts and 5 or 12V.  

[matt gray]

On 3/17/2023 at 11:05 AM, Adamw said:

I would expect the speedo has a built-in pull-up if it was originally designed for a hall effect sensor, but does turning on the pull-up make any difference?  

If that is not the problem then can you put a volt meter on the signal wire going to the ecu (other probe on gound) and either rotate a rear wheel slowly by hand or pull the sensor out and rotate slowly by hand, and tell us what the 2 voltages shown are.  It should step from something close to zero volts and 5 or 12V.  

I did try the other day changing the pull up to on and no change. 

 

Testing first with a test light then volt meter there is definitely voltage been given to the ecu. Handbrake on was 1.5v then release handbrake and it changes. It does jump around a bit not sure if thats just the meter though

[Adamw]

The video has not uploaded properly by the looks.  So what are the 2 voltage levels you are seeing?  Why does the handbrake affect it?

[0x33]

JZA80 speed signal from factory goes from the Speed sensor -> Dash -> Odometer -> ECU

The odometer changes to signal from one type to another before sending to the various ECU's on the car including the engine ECU. 

If your dash speedo works, then investigate the speed signal wiring between odometer and the Link ECU. 

Most JZA80 speedos always read incorrectly due to wheel changes etc. So normally when doing Link ECU install I change the wiring for speed signal to:

Speed Sensor -> Link ECU -> Dash -> Odometer -> Other non engine ECU's. 

Doing it this way you can calibrate the speed signal incoming to Link to be accurate, then output a calibrated signal to Dash to get speedo accurate whilst keeping the factory ODO reading accurately and other body ECU's happy (Assuming your dash wiring is stock). 

 

On passengerside footwell plug (RHD)


Cut Pin 2. 

Run the plug side of Pin 2 to a spare aux output on Link ECU and set as Speedo Out

Run the loom side of Pin 2 to DI1 (PinA2) on ECU header and calibrate as GP Speed or Wheel speed input

 

 

Pull up needs be enabled with factory wiring and with this modified setup above. 

[matt gray]

2 hours ago, Adamw said:

The video has not uploaded properly by the looks.  So what are the 2 voltage levels you are seeing?  Why does the handbrake affect it?

ahh ok, handbrake is just to stop the wheels rotating while running. wheels stopped was showing 1.5v then released the wheels it spiked to 11.3v then 3.9v.

With a led test light it would pulse when the wheels were rotating.

 

10 minutes ago, 0x33 said:

JZA80 speed signal from factory goes from the Speed sensor -> Dash -> Odometer -> ECU

The odometer changes to signal from one type to another before sending to the various ECU's on the car including the engine ECU. 

If your dash speedo works, then investigate the speed signal wiring between odometer and the Link ECU. 

Most JZA80 speedos always read incorrectly due to wheel changes etc. So normally when doing Link ECU install I change the wiring for speed signal to:

Speed Sensor -> Link ECU -> Dash -> Odometer -> Other non engine ECU's. 

Doing it this way you can calibrate the speed signal incoming to Link to be accurate, then output a calibrated signal to Dash to get speedo accurate whilst keeping the factory ODO reading accurately and other body ECU's happy (Assuming your dash wiring is stock). 

 

On passengerside footwell plug (RHD)


Cut Pin 2. 

Run the plug side of Pin 2 to a spare aux output on Link ECU and set as Speedo Out

Run the loom side of Pin 2 to DI1 (PinA2) on ECU header and calibrate as GP Speed or Wheel speed input

thanks for that will definitely look into once I figure out why the ecu isn't picking up the signal. To test the wiring from dash to ecu I have run a wire direct from the input side with no change.

I'm not sure if the DI on the board has potentially failed

[Vaughan]

24 minutes ago, matt gray said:

I'm not sure if the DI on the board has potentially failed

I have never seen a DI input fail.

From memory though (based on playing with MR2s) when wiring the hall effect sensor straight to the Link ECU you use 5V not 12V as the power for the hall sensor where the factory dash uses 12V to power the hall sensor and I have seen the ECU not pick it up when using a 12V power supply I think due to the signal not dropping low enough. This might be your issue if you have the bypassed the hardware in the dash that converts the signal and an oscilloscope would be able to show if this is the case.

[matt gray]

11 minutes ago, Vaughan said:

I have never seen a DI input fail.

From memory though (based on playing with MR2s) when wiring the hall effect sensor straight to the Link ECU you use 5V not 12V as the power for the hall sensor where the factory dash uses 12V to power the hall sensor and I have seen the ECU not pick it up when using a 12V power supply I think due to the signal not dropping low enough. This might be your issue if you have the bypassed the hardware in the dash that converts the signal and an oscilloscope would be able to show if this is the case.

thanks Vaughan the odd thing is it used to work perfectly fine 

[Adamw]

2 hours ago, matt gray said:

ahh ok, handbrake is just to stop the wheels rotating while running. wheels stopped was showing 1.5v then released the wheels it spiked to 11.3v then 3.9v.

With a led test light it would pulse when the wheels were rotating.

You need to turn the wheel slowly by hand so that you see the 2 distinct voltage levels.  You should see 0V low and either 5V or 12V high, but all the ecu actually needs is something that rises above about 2.0V and falls below about 1.5V.  If you've got 11.3 and 1.5V thats not going to work, that would indicate the sensor has a bad ground.

[don17]

On 3/20/2023 at 7:13 AM, 0x33 said:

JZA80 speed signal from factory goes from the Speed sensor -> Dash -> Odometer -> ECU

The odometer changes to signal from one type to another before sending to the various ECU's on the car including the engine ECU. 

If your dash speedo works, then investigate the speed signal wiring between odometer and the Link ECU. 

Most JZA80 speedos always read incorrectly due to wheel changes etc. So normally when doing Link ECU install I change the wiring for speed signal to:

Speed Sensor -> Link ECU -> Dash -> Odometer -> Other non engine ECU's. 

Doing it this way you can calibrate the speed signal incoming to Link to be accurate, then output a calibrated signal to Dash to get speedo accurate whilst keeping the factory ODO reading accurately and other body ECU's happy (Assuming your dash wiring is stock). 

 

On passengerside footwell plug (RHD)


Cut Pin 2. 

Run the plug side of Pin 2 to a spare aux output on Link ECU and set as Speedo Out

Run the loom side of Pin 2 to DI1 (PinA2) on ECU header and calibrate as GP Speed or Wheel speed input

 

 

Pull up needs be enabled with factory wiring and with this modified setup above. 

I have a similar problem, my speedo was working fine, but i coudn't adjusted the speed through the G4 software. when trabeling 100km/hr speedo in car was showing 120km/hr, its out because of tyre change. So I've tired wirng up the speedo as per this post linked, using a aux input and digital but dosen't seem to work, when i start moving the speedo will move up to about 10km/hr and stay there until coming to a stop? on the G4 software AUX for speedo becomes green when moving, then turns of when stopped.  anymore help would be great.

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this is my log file https://www.dropbox.com/scl/fi/z9axyr7mvv1ey4b3jz2z3/newspeedo.pclr?rlkey=y5y9f5kbiwiga20bo2odyj49n&dl=0

https://www.dropbox.com/scl/fi/dbzodpsn52jugjf2hwarf/screenshot.png?rlkey=rua4tw8akvwqdy1uokkbq99s1&dl=0