PCM Electrical Question
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Teching In
Joined: Feb 2010
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PCM Electrical Question I have a 99 Vortec 5.3 in a 92 Chevy C1500. I'm in the process of wiring the new engine computer into the truck. I have the SES light in the factory cluster working with the new computer, and I have the ignition working the PCM to turn on the fuel pump relay for 2 seconds. What I can't figure out is that I have all 4 PCM grounds to a solid ground, both orange constant (battery) power wires running straight to battery, and the 2 pink "key" hot wires that run to ignition switch, and I have the new ODB2 port wired to the computer correctly, but when I try and scan the codes with a Snapon ODB2 scanner and K9 key, it tells me that it can't communicate. I know for certain that the OBD2 port is wired correctly because there are 4 wires, 2 of which are ground, one is battery hot, and one is serial data which comes from pin 58 from the blue connector on the PCM harness. Grounds are pin 4 and 5 on the OBD2 connector, pin 2 is serial data on connector to pin 58 on blue PCM connector, and pin 16 on OBD2 connector is battery hot. Can anyone chime in on possible solutions? Thanks in advance.
