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2 Pin speed sensors!!

EFI Wiring Fundamentals

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Quick Question,

I have just retrofitted a 2 pin speed sensor into a Subaru 6 speed gear box. Does anyone know if these are reluctor types? or will one of the pins require power of some sort?



i am going out on a limb here and betting its a reluctor as Hall sensor requires power ground and signal.

There are two types of 2-pin sensors -- some are magnetic, which generally have a sine-wave output where the frequency and amplitude vary with speed.

There are also two-wire current loop hall sensors -- You need to supply them with an excitation voltage, and they vary the amount of current that flows (20 - 40mA from memory) depending on the sensing of teeth in the trigger wheel. I found these were used on the Nissan 350/370z. I was able to wire them by connecting 12V to one side of the sensor, the signal to the other side, and a 300 ohm resistor between signal and the ground.

I was able to determine that the sensors had a current loop output from the description in the factory workshop manual.