OBDII port has power but no communication | GMC Truck Forum Sep 02, 2015I have an 04 sierra and the OBDII port doesn't want to communicate with the computer when a scanner or programmer is hooked up. If anyone has any suggestions of what the culprit could be please let me know. Sent from my Rock using a Chisel Wiring Harness Information - LT1 Swap 2010 to 2011 Camaro L99 - LS3 Information, Wiring, and so on. 2001 Vortec 8 Info. 1998 to 2002 Camaro/Firebird harness Wiring Info-New PCM Pinout info specific to 98, 99-02 F-body. 3/30/2013. 2004 Pontiac GTO Wiring Harness Info - Wiring harness info 2020 diagnosis for NO Communication result of your scanner 2020 Auto wiring DLC test . The quickest way to test engine wirings in 2020 has changed. Now, you can diagnose automotive wiring problem by using the diagnostic link connector of your vehicle. It's not just plugging in the scanner and walla! You get the fix. NO..