Hi Chris,

Can't tell you much about the immobilizer, but yes normally you will still get a signal from the crank sensor, usually the immobilizer just prevents the ign and injector circuits from working (have you scoped these? do they have battery volts?). According to my data the crank sensor is a hall type half a volt doesn't sound right normally they work on 5v or 12v. I've just been stung by sensor amplitudes on a diesel Peugeot (see in diesel section).

Mark

P.S.
Just checked again, depends which ECU is fitted one has hall the other has inductive and therefore is dependant on cranking speed for output, can you check the resistance to see if it's in spec?.