C100 Connector and O2 Sensor Wiring
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I have an 03 harness that I am converting from DBW to Cable throttle for my swap. The method my tuner suggested requires me to re pin my harness for an 01 ECU so I may use the earlier OS.
Im about to finish things up but need some confirmation on a few wires.
I am using this link for all function references http://www.lt1swap.com/vortec_truck_pinouts/2003.htm
C100 Pins in question
C - Brown- Ignition 3 Voltage
The wire feeds to this connector. The two pin connector has a ground that merges with others from this portion of the harness.
![](https://farm4.static.flickr.com/3172/2772983349_f621a85c1a.jpg?v=0)
P- Dark Blue- AC low pressure sensor.
This wire feeds to this two pin connector which grounds at the same location as the pin C wire. What worries me is that a 3 pin pressure sensor plug already exists on another portion of the harness.
J- Light Blue but is listed to be Black/White (Engine ON Signal (w/SBA)) in the link I posted. The lack of congruence with the diagram has be concerned.
The wire goes to the alternator plug.
Another issue I am seeing in the diagrams is the Oxygen sensor wiring. The 2003 diagram shows wire C of the O2 sensors leading back to pins 72 and 74 at the PCM.
72-HO2S HTR LOW (from bank 1 sensor 1)
74-HO2 LOW CTRL (from bank 2 sensor 1)
Now on the 2001 diagram Pin C of the O2 sensors is simply show to be grounded at the left rear of the engine.
What do I do here? Will I be ok just grounding the wire that are show to feed the PCM on the 03 diagram?
-Ryan
Im about to finish things up but need some confirmation on a few wires.
I am using this link for all function references http://www.lt1swap.com/vortec_truck_pinouts/2003.htm
C100 Pins in question
C - Brown- Ignition 3 Voltage
The wire feeds to this connector. The two pin connector has a ground that merges with others from this portion of the harness.
![](https://farm4.static.flickr.com/3172/2772983349_f621a85c1a.jpg?v=0)
P- Dark Blue- AC low pressure sensor.
This wire feeds to this two pin connector which grounds at the same location as the pin C wire. What worries me is that a 3 pin pressure sensor plug already exists on another portion of the harness.
![](https://farm4.static.flickr.com/3241/2773830384_4749e582ab.jpg?v=0)
J- Light Blue but is listed to be Black/White (Engine ON Signal (w/SBA)) in the link I posted. The lack of congruence with the diagram has be concerned.
The wire goes to the alternator plug.
Another issue I am seeing in the diagrams is the Oxygen sensor wiring. The 2003 diagram shows wire C of the O2 sensors leading back to pins 72 and 74 at the PCM.
72-HO2S HTR LOW (from bank 1 sensor 1)
74-HO2 LOW CTRL (from bank 2 sensor 1)
Now on the 2001 diagram Pin C of the O2 sensors is simply show to be grounded at the left rear of the engine.
What do I do here? Will I be ok just grounding the wire that are show to feed the PCM on the 03 diagram?
-Ryan
#4
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I would ground pin c of the Oxygen sensors to the block. That ground is not pertinent to the PCM since all that ground is for is the heater part of the sensor and the PCM does not care about the heater portion of the sensor.
I am actually in the process of re-working a 03 DBW harness to cable and t56 for a friend of mine now.
Pin C I just eliminated, I have no idea what it is for, but I am confident that it was not necessary in my friends application because it is just there to supply power and ground to some other accy or part of the harness that he is not using anyway.
(I don`t have wiring diagrams for a 2003 truck
, actually I didn`t even have pinouts till I saw this post, I was using the ones for a 04 GTO as they are prettymuch the same)
Pin P, again I don`t have diagrams, but I know that on the newer harnesses GM began using 2 A/C pressure sensors, a 3 wire one that actually tells the PCM the exact pressure in the system and a second 2 wire one that is just a low limit emergency shutoff switch. I eliminated both of those from my friends harness as he has no intentions of running A/C
J, this one I am not sure about. I don`t specifically remember this wire or what color it was on my friends harness, but then again it was 2am when I was last working on my friends harness so my memory is a bit fuzzy right now as to what color the wires were LOL
I am actually in the process of re-working a 03 DBW harness to cable and t56 for a friend of mine now.
Pin C I just eliminated, I have no idea what it is for, but I am confident that it was not necessary in my friends application because it is just there to supply power and ground to some other accy or part of the harness that he is not using anyway.
(I don`t have wiring diagrams for a 2003 truck
![Bang Head](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_banghead.gif)
Pin P, again I don`t have diagrams, but I know that on the newer harnesses GM began using 2 A/C pressure sensors, a 3 wire one that actually tells the PCM the exact pressure in the system and a second 2 wire one that is just a low limit emergency shutoff switch. I eliminated both of those from my friends harness as he has no intentions of running A/C
J, this one I am not sure about. I don`t specifically remember this wire or what color it was on my friends harness, but then again it was 2am when I was last working on my friends harness so my memory is a bit fuzzy right now as to what color the wires were LOL
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I was hoping you would be the one to see this post.
Great info in every respect.
If you happen to remember, or ID the J pin off a diagram let me know.
The harness will be in the car tomorrow, so ill add to this thread if that pin has any affect on the system.
Edit:
Is there any chance you have the connector pinouts for the Fbody IACV and TPS sensor? I had to add these circuits to the harness and want to make sure I have things correct at the plugs.
Great info in every respect.
If you happen to remember, or ID the J pin off a diagram let me know.
The harness will be in the car tomorrow, so ill add to this thread if that pin has any affect on the system.
Edit:
Is there any chance you have the connector pinouts for the Fbody IACV and TPS sensor? I had to add these circuits to the harness and want to make sure I have things correct at the plugs.
Last edited by NoClassic; 08-21-2008 at 05:20 PM.
#6
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I will let you know what I figure out on the J pin, but I won`t be near that wiring harness until at least sunday as it is at my friends house.
I do have the 99-02 wiring diagrams, and I could e-mail them to you if you want, but they should all be here http://www.lt1swap.com/2001_ls1_schematic.htm The ones you are looking for are in # 9 and 14
I do have the 99-02 wiring diagrams, and I could e-mail them to you if you want, but they should all be here http://www.lt1swap.com/2001_ls1_schematic.htm The ones you are looking for are in # 9 and 14
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I must be missing something.
Im not seeing the TPS or IACV in either of those diagrams.
Im needing the physical pin locations within the connector. I have the wires run through the harness but have no idea what order they go into the plugs.
Im not seeing the TPS or IACV in either of those diagrams.
Im needing the physical pin locations within the connector. I have the wires run through the harness but have no idea what order they go into the plugs.