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Thunder wheel sensor


Daniel

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Ive tried the way the manual suggest and still no result.

I tried both Pull up On or Off and switching cable around from + to -. 

For the rear sensor i had the engine running on 3rd gear with the back end of the car on stands.

 

Was anybody that you are away been using the 350z/370z wheel sensor directly without going through the abs module ?

 

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Hi Daniel,

I believe this car would have active speed sensors, they are not widely used in the aftermarket world so its not going to be easy to make them work.  Although they put out a square wave similar to a hall effect sensor, I believe the driver circuit (originally in the ABS unit) is critical to get the output to span a usable voltage range. 

Normally we get wheel speeds over CAN from the ABS unit in the 350Z, have you removed the ABS?

 

You can refer to this document to understand how to make those sensors work if you no longer have the ABS unit:  https://www.motec.com.au/filedownload.php/CTN0007 Magneto Resistive Sensors.pdf?docid=3634

For our DI's you just need the voltage from the sensor to go above 1.5V and fall bellow 1.2V.

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Thank you Adamw for also posting the anwser to HPA.

I do still have the abs module somewhere in storage, unfortunatly i wouldnt know how to setup the CAN which is also probably slightly different from the 350z...

I will check at work what resistor i could use.

I suppose they would just need to be soldered in serie with the ground pin?

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The last page of the doc I linked to shows the connection, some need a pullup, some need a pull-down.

If you wanted to try connecting up the ABS unit, Im pretty sure most of the preconfigured 350Z CAN stream works in the 370.  You could try a temporary hook up to just one wheel if you want to test it.

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  • 2 years later...

Did you find a solution to this at all?

 

I’m currently going through the issue of getting 370Z speed sensors to work with a Fury. (Complete rewire, no ABS unit or CAN)
 

I’ve gone through that Motec help file that’s linked on HPA.

I’ve used the 5V reference with a potentiometer to get it near that 1.2-1.5v range, but can’t get the sensor to oscillate. The DI on the link reacts (displays ACTIVE and shows a random frequency) when I get the voltage around 2V. 
 

Here’s my table of voltages using a 12 position rotary knob.  
335D4D08-E7A8-4D05-8E20-415CF085516B.thumb.jpeg.d3a5c54a384bdcad8f19fc915e2ea4b8.jpeg

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16 hours ago, rrob said:

Early R/S chassis rear wheel speed sensors bolt into the Z diff and work directly. I don't have a solution for the front though.

Yes, there is that option and I do have some spare sensors that will work for the rear. I really do need the front one to work though, so if I can get it to work I'll use standard 370Z sensors front and rear.

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Many active sensors require 12V, sometimes pull up, sometimes pull down.  

I would try connecting the positive side direct to 8V or 12V.  Connect the negative side via a pull-down resistor to ground - try starting around 200ohm.  Measure the output at the negative pin.

The sensor above, if you tested it with your pot in the 0ohm position is probably fried.

 

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11 minutes ago, Adamw said:

Many active sensors require 12V, sometimes pull up, sometimes pull down.  

I would try connecting the positive side direct to 8V or 12V.  Connect the negative side via a pull-down resistor to ground - try starting around 200ohm.  Measure the output at the negative pin.

The sensor above, if you tested it with your pot in the 0ohm position is probably fried.

 

The final position on the trim pot read 00.4 on the 200ohm setting (I rounded down). Would that have saved the sensor?

 

Before using a 5v supply i bench tested it with a 12v battery (with a 330ohm pull up) and could get it to oscillate around 8.4-8.8v. If I use a 12v supply on the car I would need to find a stable source right? Otherwise speed will fluctuate with battery voltage change?

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I just did a quick test with a battery I had laying around. 330ohm pull down resistor. Can get it to oscillate 2.24-4.62V 

- is it bad that I’m using a magnet to trigger it? It’s the only way I can get it to switch. 
 

I’ll give it a go with the 8V but does it look like I’m on the right path? I’m aiming for below 1.2 and above 1.8 eventually right?

11 minutes ago, Adamw said:

There is a regulated 8V output on the ecu.  Try the pull-down variation.

Cheers. I'll try that when I'm with the car next. 200ohm pull down still?

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I'm testing this on the bench (using a G4X 8V and sensor GND) and can only get it to oscillate between the two values by tapping the sensor on a magnet. Is that ok?

Results:

8V supply

160R pull down: 1.1V - 2.262V

200R pull down: 1.375V - 2.831V.

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9 hours ago, Dean said:

Could I get someone’s confirmation that the Motec DMC-D will work for my situation before I get it?

DMCD is just for normal AC VR sensors.  DMCF is for magneto resistive sensors but only does one sensor so it will get expensive quick.  I have never used one so I dont know much about them.

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  • 3 weeks later...

I have the sensor on the car now. 
8V supply, 160R pull down resistor.
 

This video is with the positive probe on the signal wire, negative to ground. I’m gently turning the wheel and can get it to react with the multimeter (1.1-2.2V) 

Nothing shows up on the DI input though. I’ve tried spinning the wheel as fast as possible, and also changing the ECU pull-up resistor and rising/falling settings.

I can get the DI to say ACTIVE if I disconnect and connect the signal wire (it also shows a speed if I do it quickly)

I feel like I’m close to getting it working! Is there anything else I can try to get it to work?

Cheers!

It’s actually 1.09 - 2.25V when I use the sensor ground. 

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On the bench with my test ecu, I get 1.80 and 1.00V as the thresholds.   So I suspect your 2.2v is ok but maybe doesnt drop quite low enough.  

If you set your DI to a GP input, with on level set to high, can you check that it switches to active when the sensor is showing 2.2v and it should stay there.  That will at least confirm the DI is happy with the high level. 

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