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Just for reference, a 2 wire signal is probably providing a voltage with a round wave pattern (analog) and the change is often more waves with speed AND amplitude (voltage increase with speed increase.)
A 3 wire sensor is probably a hall effect. This sends out a square wave (digital) with pulses. Faster is more pulses.
Yes the 2 wire speed sensors send a small ac anolog voltage signal and the 3 wire sensors send a digital hall effect signal as they are hall effect sensors.
The 2 wire ac sensors in the tailhousing of the 518 is not used for the speedo but it is used for the electronic govenor as it needs to know the output shaft speed to control throttle pressure. These vehicles usually use the rear diff 2 wire sensor for the abs for the speedo. The abs module sends the signal to the pcm as it is either hard wired or sent over the buss. Then it goes to the cluster. Ron
Last edited by 383man; 05/22/10 11:00 AM.
