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Old 05-03-2017, 02:46 PM   #69
MRS-Colin
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Join Date: Jun 2016
Drives: 2001 Impreza 2.5 RS
Location: Dayton, Ohio, USA
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Quote:
Originally Posted by gtpvette View Post
Thanks Colin! Have a question regarding the DLC connection as I'm real new to this CAN stuff. My PCM has two 'High Speed GMLAN Serial Data' pins a + and -. Would those be the correct inputs to your device?? Is it fair to assume I'd be able to read fault codes from the motor off the FRS DLC??


Thanks again
The DLC plug (red) we provide is set up already so you don't have to worry about which side of the bus you are connecting to (low or high)

CAN bus is a two wire protocol with differential signals. This is a good way to protect against EMI and other interference on the lines. You have a + and - line (high and low) which results in a waveform like this:



You can see the low and high lines are exactly opposite of each other.

Yes, you can read fault codes of the GM PCM through any normal fault code reader through the FRS/BRZ DLC. The GM PCM is actually on the same bus as the rest of the vehicle (as if you just one for one replaced the FRS/BRZ ECU with the GM PCM). With our gateway we then block these specific generic requests so that the FRS/BRZ ECU does not see them so it will not respond. Some advanced scan tools like factory scan tools that use non-generic request ID's will still be able to communicate with the FRS/BRS ECU.
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