L84sky

I spent the morning verifying colors on the PCM wiring.


One discrepancy I found involved the pins on the EGR valve.


Chevy and Suzuki use the same pin numbering on their EGR plugs but the schematics showed the PCM wires going to different
EGR pins. I needed to examine the EGR plug on my Tracker to see who was correct and that is not an easy thing to do on the V6 engine.


Using a tripod, remote shutter release, zoom lens and a mirror; I was able to get a picture of the EGR plug wiring. Turns out the Chevy documentation
was correct. I uploaded the changes to the PCM schematic here: https://www.dropbox.com/s/o8wvar0nai...ed%20.jpg?dl=0
I also updated the link on the "intro to the PCM" post.

Rich Engle

if you need more wiring diagram, pls contact me

L84sky

Rich, thanks for bringing the broken link to my attention. I had updated the PCM schematic and forgot to update the link to it. The link works now.

Rich Engle

Do you know how the wires get from the maf to the PCM? I have a short in that wire

L84sky

All three MAF wires are part of the engine harness ("C" harness in the Suzuki manual).



The Engine harness and half of the Main harness ("E" in the Suzuki manual) pass through the firewall
at P101 (Chevy's desgination for the firewall pass-through on the passenger side).



Inside the cabin the MAF signal and ground wires terminate on PCM C2 (Suzuki designation C51-3). C212 is Chevy's designation for connector 12 in zone 200.
The Suzuki designation for C212 is C52/E59 (connector 53 on the engine "C" harness to connector 59 on the main "E" harness).



MAF power comes from pin 2 of the main relay on the junction block in the driver's footwell, runs under the dash through the Main harness ("E"),
then connects to the Engine harness ("C") at C212 (Suzuki E59/C52) then out P101 to the MAF sensor.

Devo Stevo

I am a stumped newbie at reading wiring diagram for my gm 4.3. What does the 'S' followed by numbers indicate? And can you suggest some source that covers reading auto electrical diagrams I understand 'G'101 is a ground location, and you explained 'P'101 is a pass through. TIA

L84sky

S219 is the 19th splice in zone 200. See Tracker 101: intro to splices - Chevrolet Forum - Chevy Enthusiasts Forums for more detail.


These are the zones for my Chevy Tracker.