Did you eventually get to the bottom of this Steve? I have a civic with the exact same symptoms as yours! All powers and grounds are correct and scoping at the ecu I have 3 clean scope patterns relating to the sensor it is sent from. Yet still no trigger from the ECU and no rpm in live data. There is no evidence to condemn the ECU, no fault codes and MIL lamp comes on for 2 seconds and then goes out... Baffling

Cheers
Ben