My trailer interface module won't program with the Tech2 due to my chassis number (A13DTE engine shouldnt have a towbar fitted it seems) 

When it reads the VIN as part of programming it refuses... even if i use the VIN thats stored in the TIM, that's from a 1.7 engined meriva, 

So i removed the GM-lan wire from the TIM, connected that to the tech2's obdii connector... pin 1 - gm-lan, pin 4 and 5 to earth, pin 16 to power, 

i can talk to the TIM with the tech2 like this, read DTC's, oper