2003 - 2004 Chevy Truck Tach

What size engine are you working with.

This is a 4.3 lit.  PCM plug is Blue. This is off of the crankshaft sensor. Pin 12 Yellow wire circuit 573.

I cannot find any RPM wire at the PCM on the 4.3 - 4.8 - 5.4 - 6.0 for 2003 or 2004

The Crankshaft sensor or the Camshaft sensor should provide the required signal, it is not the cleanest signal.

(or connecting to one of the coils)

why make life difficult?  the fuel injectors are very easily accessible, and provide a solid signal.  we've found Autostart will not work right UNLESS we use the injector.  if I remember correctly on the V8 models its /not/ the pink wire...

b

why make life difficult?  the fuel injectors are very easily accessible, and provide a solid signal.  we've found Autostart will not work right UNLESS we use the injector.  if I remember correctly on the V8 models its /not/ the pink wire...the coil for each cylinder will NOT provide tach...it measures very low, and Autostarts don't see it.

b

hey doc....good stuff.  although, please note in my above post I clearly put /not/ pink    we've found this is the only really reliable tach in these trucks for Autostart products.  have done MANY this season and never had an issue with the SES light...

b