If you get an adapter (J1939 type 2 - green to OBD2) in order to use a conventional code reader or other ODBII device, you may need to swap the ground pins in the OBDII connector side because the adapters often take the ground pin of the J1939 (pin A) to pin 5 (signal ground) of the OBDII but your device may need Chassis Ground on pin 4 instead. (I had this issue when trying to use a Banks iDash, but couldn't get the iDash to read Freightliner stuff I wanted anyway..)
Thor Forums
