Here is the info i have found on the Internet from MPPS V18 china device.
MPPS V18 PCB Schematics
MPPS V18 Tricore Cable Pinout
Some problems on China mpps v18 maybe on new ones it is solved:
ON the tricore cable the +12v switch is only on t he pin 16 of the obd female, so it cuts +12v only on the tool the ecu is always poweered for solve it you can put a switch for cutting all positives and other for minor positives.
Boot wire have no resistor to ground.
And http://www.obdexpress.co.uk/wholesale/mpps-v18-breakout-tricore-cable.html this is a Tricore cable of high quality and tested good