How do you check a crank angle sensor to see if its functioning or not? Can you use a multimeter?

Ideally you want an oscilloscope to check it and I'd assume its a square wave signal.. Not too sure on how to do it with a multimeter, but you'd need a copy of operating voltage range first.

TUFF,

For the 3rd Gens, the "Tech Torque" workshop manuals have Cranks Sensor diagnosis in Chapter 13A, on page 16 of that section. Hopefully, the 2nd Gen Workshop Manual will have similar info.

The 3rd Gen manual has you disconnect the loom connector for the Crank Angle Sensor, and test voltages of each pin to Earth. Think they also intend you to check voltages with the sensor connected, using some test harness special part: Terminal 2 to Earth when sensor connected - cranking OK is 0.4 - 4.0 V
Terminal 2 to Earth when sensor connected - idling OK is 1.5 - 2.5 V
Disconnect the sensor at harness connector, measure at Harness side with Ign Key ON:
Terminal 3 to Earth OK is "system voltage" so assume 11.0 - 13.0 V ???
Terminal 2 to Earth OK is 4.8 - 5.2 V
Check continuity from Terminal 1 to Earth - OK is continuity

I don't have these PDF's for 2nd Gen so can't tell you what is kosher for the car I assume you are working on.

Hope this is some help.

Hmm....Thanks for that mate. Just have to find out if the CAS is dead or not, Cause it wouldnt start yesterday due to no spark. So have to start fault finding for the 3 weeks left I have it for. Thanks for that information mate

Mate, grab a noid light and see if you have injector pulse, if you do then the CAS is not your issue.

Positive to signal and negative to ground on oscilloscope. So should be able to check it a multimeter.

Mal could you expand on how the injectors are dependant on the CAS signal. There might be a problem the injector wiring at the moment also (wiring is confusing)...

The CAS will tell the ECU when the engine is at TDC, on the s4 engines for instance the CAS gets 3 signals for each crank rotation.

The ECU will not send a signal to the ECU or to the Fuel pump if there is no CAS signal, the pump cuts when the CAS signal is gone as a safety precaution incase there has been an accident and a fuel line is cut as the pump can empty a tank pretty damn quickly