squared

Trying to connect my wideband via the A/C pressure sensor input, and use PID 7101 to monitor. Since I don't have the harness for my setup, I need to direct wire the sensor to the PCM (0411). Does anyone know the correct PCM pin? A 2001 silverado shows red pin 17 and red pin 55 as A/C pressure sensor inputs, but when I use a AAA cell on the pin, no voltage shows on the PID output.

gagliano7

Pin 55 is what you want not 17.17 is a/c request which receives 12v. I have never used the A/C. I use the EGR PIN 55 blue connector for volts for wideband and i used pin 23 egr ground for the wideband. Just enable egr in tune while using wideband. Not sure how a AAA cell is used for checking voltage i use a multimeter.

JoeNova

Red connector pin 14.

squared

Thanks for the help

squared

Just to clarify on the AAA battery, forgot to mention I'm hooking it up through HP Tuners.

On the scanner, when you choose and display A/C pressure (PID 7101) it shows the 'output' in volts (or millivolts, if selected). So, I figured if I connect the positive end of the battery to the pressure input on the PCM and ground the negative end of the battery to engine ground, it should display ~1.5 volts in the HP scanner. (with engine on and recording).

I did this to verify that I had the right pin for the wideband setup. Since I didn't get a voltage reading out of the HP scanner, I figured neither pin was the correct one. I could use EGR, but I'm already down the A/C route. It's in my boat and I might use EGR at some later point in time.

After a little more research this morning, and looking at the 02 Camaro schematic, I saw that Red pin 14 was the A/C pressure signal input..confirmed by JoeNova and will give that a shot even though my PCM firmware load is from an 01 Silverado.

I'm assuming that the internal circuitry and hardware-pin setup is the same for all of the 0411 PCMs and that the 'PID' is essentially a pointer to the memory location that's 'physically' connected to the PIN. If that's true, then if there's a PID-PIN association with a different 0411 vehicle (camaro in this case) that doesn't exist in the one that I'm using (silverado), I should be able to use that analog input to sense and translate the signal. (Assuming the firmware flash supports the address).

JoeNova

The hardware in the PCMs over the years changes a lot less than most think. With some minor exceptions, all of the PCMs are interchangeable. You can take a Blue/Green DBW PCM from 06 and plug it into a Blue/Red DBW harness from an 03 and everything work fine.

patSS/00

iTrader: (6)

Does that include o2 sensors and closed loop?

JoeNova

O2 sensors unfortunately did change between case ground and isolated ground.
You'll have to replace the O2 sensors themselves.