Assuming you are using the bosch type sensor, this is the pin out.
Connector
pin Color Function
1
Black Vs
2
Green Rcal
3
Grey H+
4
White H-
5
Yellow Vs/Ip
6
Red Ip
I pulled this off the bosch site. The gray and white wires are for the heater.
On most systems the gray wire is hot all the time. ( between 10.5- 14.0 volts.
The white wire on heater is switched to ground through the mosfet.
So if the sensor is not up to temp, the white wire will show a low voltage.
Once the sensor heats up the white wire voltage will rise.
The mosfet can cycle very fast, so if you don't have an oscilloscope it may be difficult to tell once the sensor has heated up.
The easiest way to tell is to observe the voltage on the white wire with a DVM when the sensor is cold at initial power up. Once the sensor heats up the voltage should rise. This usually takes about 60-110 seconds.
To measure this you will need to put the DVM on the appropriate setting and hook the ground lead to chaise ground and the positive lead to the white wire.
If the voltage never rises on the white wire the controller is most likely damaged.
This should give the results you need to determine weather your controller is working properly. But if the information is unclear let me know..
There is another method used to control the temp. of the sensor.
this method holds the white wire to ground all the time and regulates the voltage to the gray wire. In that case you will hook your meter to the gray wire and watch for a voltage shift during warm up.
If you need more info on the wiring of the sensor you can visit this web site.
www.megamanual.com/PWC/wire.htm
