DIAGNOSTIC TECH wiring utilizes a twisted pair wiring, and this is because any electromagnetic interference on the harness will affect both CANH and CANL electrical signals equally so that the voltage difference between the two is unaffected if such a condition were to occur. Additionally, you may not always find the exact info you need within service information. Often, I find myself researching training documents offered by the OEM or aftermarket resources for additional insight. ERROR REPORTINGhttp://www.VehicleServicePros.com