LS Harness Woes

[JJAB]

Guys I am having a nightmare with my 6.0. We don't have enough time for me to go through all of the issues that I have dealt with and dealing with on my 6.0 build. Here is my current problem. After two visits with the custom tuner I am having a 02 sensor reading problem. My bank 2 sensor is reading 47 when it should be reading 420 to 440. The tuner ran a special y band test on that side to eliminate possible motor or injector problems and the conclusion we came to was this. I need the diagram of the 02 sensor plug so i can compare what the voltage of each wire is as to what it is supposed to be. And also, one of those wires should be a ground, so I am going to check for ground.

That bank 2 sensor not reading correctly is showing lean and causing a dumping of gas on that right side. Does anyone have a diagram and voltage specs?

[usmcchevy]

Converted harness or new harness? what year?

[JJAB]

The harness is the original 2002 harnes from the Chevy pickup, so I guess it would be consisdered a converted harness.

[usmcchevy]

I'd start with doing some continuity checks on all of the O2 wiring, past that maybe you just have a bad O2 sensor.

[JJAB]

I have exchanged the 02 sensor 3 times. I started with a new 02 sensor and exchanged it twice. The 02 sensor plug is horizontally shaped with 4 wires. Maybe I am not looking at the diagram correctly, but I only see two wires on the diagram. I will need to do a volt test on each wire. The sensor wires in question is bank2 sensor 1.

[JJAB]

ok after a second look, am I reading the diagram correctly. For the bank 2 sensor 1 it says:

A - black .8
B - Purple .8
C - Pink .8
D - Black .8

Is this correct and what is the .8? Should I ohm or volt test the wires and how can I find out what each wire should ohm or volt test to?

[usmcchevy]

.8=size i believe
Bank2 sensor 1
A-Tan
B-Purple
C-Pink
D-Black

Test Continuity A to PCM Blue pin 26, B to PCM pin 66 and D to ground. All should read less than 1 ohm

With key in run test for 12V at C

[JJAB]

Thanks for your quick response. I will keep you posted on my results

[TR65]

Yep, The 0.8 is the metric wire size. Here is the conversion.

Metric__English__Amps
0.35_____22______7
0.50_____20_____11
0.80_____18_____16
1.00_____16_____22
2.00_____14_____32
3.00_____12_____41
5.00_____10_____55


TR

[JJAB]

ok guys, what direction do I go from here. I test each wire to the 02 sensor plug. The black wire did test ok as a ground. The pink wire did test to 12 volts. The tan and purple tested at 4.5 ohms instead of below 1 ohm. What now?

[usmcchevy]

Has the sensor been swapped to the drivers side to see if the problem follows it?

[BustedTruck]

Make sure the wires are in the right cavites. A is tan, B is purple, C is pink, & D is black. Also bank 2 sensor 1 should switch back & forth. The sensor should be around 450mv unplugged.

[JJAB]

I am afraid that the wiring of the harness has a flaw. Unplugged, it has a reading of 45.

[BustedTruck]

Why dont you try removing wire #26 & #66 from the pcm connector then reconnect everything & see if you get 450mv then. If you do its in the wiring. If not most likely a bad pcm.

[JJAB]

OK. I will attempt to do that. I will let you know the outcome. Thanks!!

[clinebarger]

Check the purple/White wire in the harness for a short to ground with PCM & O2 sensor unplugged.

[BustedTruck]

Originally Posted by BustedTruck

Why dont you try removing wire #26 & #66 from the pcm connector then reconnect everything & see if you get 450mv then. If you do its in the wiring. If not most likely a bad pcm.

I apologize this is incorrect information. Its been a rough week. This will not work. I should have said when the oxygen sensor is removed, but still connected it should read 450mv. Make sure all the terminals are in the right holes, then ohm each wire out end to end, and ohm them out to ground to make sure they are not shorted. Again sorry about the confusion.