FYI.... The MSD Dashhawk OBDII display DOES NOT work with the 2005-2006 Scion tC. It only works with CAN compatible ECU/ECMs that have pins 6 and 14 on the OBDII connector. The tC does not, therefore, is not recognized by the Dashhawk. Not sure about the 2007 tC as there were some revisions to the ECM. It does work, however, on my 2007 Tundra 5.7L Crewmax and 2007 Camry V6 SE.
It is my understanding that all of the OBDII Monitor displays out there either don't work at all or provide very little information when it comes to the tC. According to the Scion tech manuals, the tC is a CAN enabled ECM that is fully compliant with the OBDII specification. What experience has any of you had with these display units? From the information that you receive from these devices, do you feel it was worth the purchase?