Can't connect to OBD port for Engine module

[jtmdmd1]

I have always been able to read & erase codes from all modules with my generic VAG/OBDII scanner. After my last Timing belt/etc service my MaxScan scanner wouldn't read the engine module codes- it will read the Transmission & erase all codes. I bought a new one & still the same thing. What do you think is going on? It had worked fine for the 4 years I have had the car & wanted to make sure there weren't any new things going on besides my usual codes that give me a CEL. I took the car back to my mechanic to check a few things out & it seemed to take his unit a long time to get the codes.

Thanks

[UrS6]

Do you have a tune? Also check the ECU plug in the cowl. Make sure no pins are bent

[jtmdmd1]

No tune but i will try the ECU pin.
Thanks