Exactly where is the PCM located on a 99 Sierra, and how do you physically get to it?

Also where do the knock sensors go into the PCM?

Pardon my ignorance,

Thanks,

ts99

 

Its under the hood. Standing in front of your truck, it is located on the right behind the radiator near the fender. How to get it out, I cat help ya with, sorry. Are you wondering about which wire colors are coming from the knock sensors or where the snesors are?

 

Where the sensor wires come from and where (what color) do the go into the PCM.

 

the knock sensors are under the intake manifold inside the valley cover (kinda)....i'm not sure what color the wires are though.

 

Let me guess SES code P0332 knock senser low input.If you pull off the intake cover ontop of your engine,on the drivers side back of the intake theres a 2 wire plug with a light blue and a dark blue,grab a multimeter and set to 200k ohms scale and ground one of the meter leads.Measure the knock sensor resistance it should be between 91k and 110 k ohms.If it is not let us know and I will dig up what to do next.GM has a tsb on the rear knock sensor for corrosion.

 

Sorry, nos SES codes, but I do have 8* of false knock retard. I am going to put a resistor in each sensor line to de-sensitize the sensors.

I still have not found the PCM and the wires coming from the intake (sensor wires) so I can add the resistor.

Need further direction,

Thanks,

ts99

 

email bigtex or parish8 they're modorators here and i know richard has done somthing similar and i think parish did also at one point.

 

There was just a post on knock box install about 99's having 8* false knock. Look for that thread, couldn't more than a week old. I know the label has Knockbox in it.