I'm new so forgive me if I'm out of bounds or on the wrong thread. My question is about the wire colors for the O2 sensors on a 2001 4.3L. After an engine swap and modified harness, I'm having a difficult time finding the appropriate diagram for my engine and PCM,,,, Or are they the same for a certain year range? Thanks for this forum and your patience with a newbie.

I appreciate any assistance offered.

 

Welcome to the forum. I've got the pin outs for a 2000 if the colors and numbers match yours I'd try it. The heated O2 sensor wires go to the BLU connector at the pcm. The pins are numbered.


17 **************32
1***************16

Pin # Wire Color Function

7 Tan HO2S Bank 2 Sensor 1 Low

19 PPL/WHT HO2S Bank 1 Sensor 1 High

21 PPL HO2S Bank 2 Sensor 1 High

22 PPL/WHT HO2S Bank 1 Sensor 3 High

25 TAN/WHT HO2S Bank 1 Sensor 1 Low

26 TAN/WHT HO2S Bank 1 Sensor 3 Low

Hope yours matches and that's what you're looking for.

 

2000 and 01 are completely different computers.

 

Thanks, I appreciate you taking the time to help. The wire colors you've indicated (short of a couple) mimic the colors in my harness, but the pins as they are currently located aren't altogether the same. I wish I could find a diagram specific to my year to help me make sense of it.

 

That might explain some of the differences I'm encountering. I found a pinout chart for the 01-02 4.8-5.3 V8's and many of the wires/pins coincide with what I'm seeing but, I'm still not confident its appropriate to the 4.3L V6. If I could find a diagram detailing the specific wire to pin locations for a 2001 Blazer I'd be set.

 

The factory service manual set for 2001 S & T series trucks will be 100% accurate for every wire.

 

BLUE CONNECTOR
TAN HO2S -----Low Bank 2 Sensor 1 Right Front O2 C1 26
TAN/WHT HO2S Low Bank 1 Sensor 2 Post Cat. O2 C1 28
TAN/WHT HO2S Low Bank 1 Sensor 1 Left Front O2 C1 29

PPL HO2S ------High Bank 2 Sensor 1 Right Front O2 C1 66
PPL/WHT HO2S High Bank 1 Sensor 2 Post Cat. O2 C1 68
PPL/WHT HO2S High Bank 1 Sensor 1 Left Front O2 C1 69

 

Thanks Guys,

I greatly appreciate all these rapid responses. I think I'm on the right track now, the numbers and pins seem to closely match what I'm indicating. Looks like I only had one wire in the incorrect pin.

Hope everyone has a safe and Happy new year.