I'll dive right into it. I have a fresh b20vtec running on an obd2 p72 (Gs-r) ecu.

After starting the motor up, checking for leaks, setting the ignition timing etc... I got into my teg to an expected CEL.

I used the paperclip trick to obtain a code 22 (Vtec oil pressure switch). I triple checked the wiring, but have no 10 volt signal coming from the ecu to the switch...

I know this has been covered in the past but I've read two different pieces of information about wiring the Vtec Pressure Sensor in an obd2 Integra.

Firstly I've read that only Pin C15 goes from the ECU to the sensor Blue/Black wire). The other (black) wire gets grounded from the sensor to the chassis.

The other setup I read was that instead of getting grounded, the other wire returns to the ECU as a signal?

I don't think the latter is true but if someone knew for sure it would help me move on in diagnosing my problem.

Thanks in advance!

 

Yes, at least on mine ('96 GSR) I have a wiring diag manual for...

BLU/BLK from pin 15 of C409 to pin 1 of C132 of the pressure switch. Pin 2 of C132 (BLK) goes to ground point G101 (the thermostat housing).

 

Awesome! Thanks for the confirmation, one theory down! I'll look into the 4,725 other possibilities!