?? how to test a crank sensor??

[dave5688]

Does anyone know how to test a crank sensor? I have a 98 beetle 2.0 with a no start condition. It cranks but no start. It went from intermitant to not starting at all. I have replaced coil and fuel pump relay. It is getting fuel. No spark to plugs. I have 12 volts to coil no pulse to coil. I wanted to test crank sensor if possible.

[geniushanbiao]

There are 2 ways to test.
1. Use multimeter, test the resistance between the 3 terminals of the sensor. 1-2(might be 2-3) should be between 480 and 1000 Ohm and the other 2 should be inf. If not the sensor is bad.
2. Use VAG-COM and laptop to log the crank sensor data. During start you should be able to see the curve.

[dave5688]

just to make sure do you mean to test between 1 and 2 and between 2 and 3?

[geniushanbiao]

I can't remember. Anyway, you have to test all the 3 possibilities. They are 1-2,2-3, and 1-3. Among the 3, 2 should be inf and the other should be 480-1000 Ohm.

Originally Posted by dave5688

just to make sure do you mean to test between 1 and 2 and between 2 and 3?