Vehicle speed on Toyota MR2

[-Totenkopf-]

Trying to work out if the vehicle speed input on the SM4 can take a signal from the sensor mounted to the gearbox on my MR2 Turbo. My vehicle uses the later model electronic speedo sensor as opposed to the cable driven type.

Has anyone configured this before and can offer me any assistance?

Cheers,

James.

[Kevin Black]

You first need to determine if the sensor is Mag (variable reluctor) or Hall Effect.

Here are the rules:
2 wires, has to be Mag
3 wires, can be either Hall or Mag
To find out, see if there is +5 to +12 volts going to one of the wires, by looking at the wire diagram, or measuring.
If there is power, then it is Hall Effect.
If no, then it is a Mag sensor with the 3rd wire being a shield. You should get 500-1000 ohms between 2 of the wires, none to the other wire, and/or in the diagram you will see one or possibly two of the wires going to sensor ground.

Hall Effect - signal wire straight to the SM4 HSI3 Input
Mag - You will need to buy an Autronic Reluctor Interface (adapter for Mag) and you will be able to use the sensor.

[-Totenkopf-]

Thanks for the info Kevin, will get a fluke out today. Its a 3 wire sensor, so could be either. Like bloody everything else on this Toyota its probably reluctor type.

You first need to determine if the sensor is Mag (variable reluctor) or Hall Effect.

Here are the rules:
2 wires, has to be Mag
3 wires, can be either Hall or Mag
To find out, see if there is +5 to +12 volts going to one of the wires, by looking at the wire diagram, or measuring.
If there is power, then it is Hall Effect.
If no, then it is a Mag sensor with the 3rd wire being a shield. You should get 500-1000 ohms between 2 of the wires, none to the other wire, and/or in the diagram you will see one or possibly two of the wires going to sensor ground.

Hall Effect - signal wire straight to the SM4 HSI3 Input
Mag - You will need to buy an Autronic Reluctor Interface (adapter for Mag) and you will be able to use the sensor.

[-Totenkopf-]

Went and had a look. Had ~10V on one pin on the connector, so I assume that means its a hall effect sensor. I'm just doing some initial research ATM as I'm still awaiting a clutch for the new engine.

I can just T off of the signal wire I assume and run it to the SM4. It currently already runs through the bodyloom connector to the speedo.

Cheers,

James.

[turboe36]

The diff speed sensor in my BMW is mag, but somewhere in the car it is converted to a digital signal. Check if you had a speed signal wire going to your stock ECU. If you do, I'd bet its a digital signal. Worth a shot before purchasing the mag interface.

Or yes, scope the wire to your cluster and see if it is an a/c signal or digital signal.

[-Totenkopf-]

From memory, yes the ECU took a speed signal. So its probably digital. Also from Kevin's explanation, and having a power feed to the sensor, its should be a hall effect type. I'm assuming that all these vehicle speed sensors work similar or something, and don't pulse at different rates? If I connected this straight up it'd work?

Cheers,

James.

[turboe36]

Whoops, I missed that. I believe a 5-12v signal is acceptable so you should be all set! I'll let someone else confirm though. :)

[Gert]

I can just T off of the signal wire I assume and run it to the SM4. It currently already runs through the bodyloom connector to the speedo.
Yes, I did that, and it worked.

Gert

[nisse järnet]

The diff speed sensor in my BMW is mag, but somewhere in the car it is converted to a digital signal. Check if you had a speed signal wire going to your stock ECU. If you do, I'd bet its a digital signal. Worth a shot before purchasing the mag interface.

Or yes, scope the wire to your cluster and see if it is an a/c signal or digital signal.

What BMW was that? And what cable? I have a 325i -88 and i want to get my speed into the SM4 :) Is it best to use the diff speed sensor or one of the ABS sensors?

[MRMRacing]

If you just want speed it is easy to hook up to the Diff. On my son´s Volvo 960 which has a Sm4 has a mag sensor at the diff and is converted in the speedometer to hall type and then linked to the motronic ecu (now Sm4).

[nisse järnet]

If you just want speed it is easy to hook up to the Diff. On my son´s Volvo 960 which has a Sm4 has a mag sensor at the diff and is converted in the speedometer to hall type and then linked to the motronic ecu (now Sm4).

Yes, i just want speed :) ( i think hehe) But im not sure if my beemer has speed input in the standard motronic ECU? Does anyone know this? If it doesnt, should i get a reluctor or go with the ABS sensor? (2 wires in the ABS cable)

[MRMRacing]

If you got a wiring diagram you can find out or use a reluctor interface, but be carful with the polarity so you don't mess with the ABS function.