How to test a bad speed sensor?
 

Is there any way to physically test and see which speed sensor on the wheels are faulty, without checking the codes?

It's very tedious to remove wheel, disconnect connector for wheel sensor at each wheel, and measure resistance. Much easier to access the ABS code by shorting the service check connector and reading the flashes to determine which wheel sensor is putting out a fault code.

Once you know which wheel, you measure the resistance of the sensor to determine if sensor, wiring, or perhaps dirty pulse wheel is cause of the problem. Front sensors (2.5TL) are 700-1000 ohms and rear sensors are 550-850 ohms. Why they would be any different is strange, but that's what manual says.

I have found a dirty pulse wheel and/or sensor to cause the wheel sensor fault by degrading the output signal. Clean sensor and pulse wheel w/ rag stuffed into sensor opening against the pulse wheel to clean the cogs.

good luck

Do you have any link on how to short the service check connector? I did not know that you can do that on 01 TL since the ABS code can be read by computer. My ABS, TCS and BRAKE light are all on and every one says it is a bad sensor.

I have a 3.2 TL and a couple of years ago my speedo stopped working. The mechanic first replaced the speed sensor at the transmission end and that didn't fix it. He replaced the car's computer module and that did the trick. He got the computer from the same model in a salvage yard in another state - costs me $500 - a new computer through the dealer would have been over $1,000.

I thought the speed sensor was on the Tranny?

Indeed there is a speed sensor on the tranny, however the ABS needs to know the wheel speed of each wheel to determine if one or more is sliding under heavy braking. ABS computer then actuates ABS modulator to reduce wheel slip when brakes are applied. This allows steering function to be retained on front wheels.

regards

similar problem
 

mine is having the same problem now. the speedometer doesnt work, sometimes it goes bat shit crazy and says in going 80-100 mph when im still in first gear. and sometimes it messes with the rpm gauge and it revs but doesnt shift, is that related to the speed sensor too? the check engine light came on, and shot out 3 codes, 1. P0500 Vehicle Speed Sensor (VSS) Circuit Malfunction 2.P1791 Vehicle Speed Sensor (VSS) Range/Performance Problem 3.P0700 Automatic Transmission Control System