Originally Posted by the Rave, more or less
Both pins of the CKP sensor are outputs, to protect the signal the cable has an earth shield.
the ECM measures a positive single on the pink black wire and a negative on the white/blue.
Voltage generation from the ckp is relative to engine speed. A good CKP produces 2-3 volts while cranking and 6-6/5V at 1Krpm+
The airgap of the CKP to the reluctor ring will adjust the voltage.
The signal can be incorrect if one or more of the following occour.
sensor assembly loose
incorrect spacer
sensor Open circuit
sensort short circuit
incorrectly fitted
water ingression
There is no backup strategy for the CKP.