Wiring Diagrams

Oxygen Sensor Color Codes

You might be able to get all the information you need if you can find your sensor in the following document: Oxygen Sensor Color Codes (pdf). It doesn't cover all makes and models, and no wide band sensors are included. But if your sensor is listed, then you can identify the signal wire on the sensor itself. By noting which wire it corresponds to on your vehicle's wiring harness, you can then also determine which wire color carries the signal back to the ECU. This allows you to attach the EFIE wiring wherever is most convenient without needing a wiring diagram at all.

If You Need A Wiring Diagram

You can get the wiring diagrams of your car from Mitchell's Online Repair Manual web site. The way to do this is to sign up for their 1 week subscription, which costs $10.49. This is a one time payment, and entitles you to access for 1 week. You'll then want to copy the wiring diagrams and save them for your future reference.

Note: Unfortunately, this service is only for models that are sold in the United States.  Models that are not sold here are not covered by this service.  This includes domestic manufacturers, that make models sold only in overseas markets, but not in the U.S.  If you are aware of a similar service that supplies diagrams for foreign makes and models, please email me, and I'll update this article with the information.

Once you've logged in, you'll do the following steps:

1. Go to Mitchell1's web site.
2. Press their "Subscribe" button, then select your vehicle, and finally pay them to join their service. You only need to sign up for 1 week.
3. Press the "Repair" button.
4. Select "Wiring Diagrams"
5. Select "System Wiring Diagrams"
6. Go down until you find the section "Engine Performance Circuits"
7. Copy these diagrams. All of your sensors will be included in this section.
8. If you want any other diagrams, copy and save them as well.

Copying the Images

The images can be copied with just about any image processor, even Microsoft's "Paint" program. I'll describe the steps below for several image programs, including Paint.

If you use these images directly in your browser, you'll need to blow them up. You'll see a link at the top "Click Here for full size versions". However, you don't need to blow them up when copying the images. They'll copy full size by using the following instructions. In each case, in the instructions below, you're going to open an image editing program, and then drag the image from your browser and drop it on the image editor.

In case you don't know how to drag and drop, you put your muse over the diagram in your web browser and push down the left mouse button. Hold the left mouse button down and move your mouse over your image editing program. Then release the mouse button. The full sized image will be copied into your image processor.

I'm describing the steps for 3 programs below. However, you may have another image processor that you want to use. It will probably work. Just make sure it supports drag and drop, and that it will save your image as a jpeg file. The other image types take up too much disk space.

Photoshop

I use Photoshop. It's professional software and you have to pay for it. If you have it, this is probably the easiest program to use. For each wiring diagram image you want, just drag it onto your Photoshop window. You can drag and drop all the diagrams you want at one time, and Photoshop will make each one into a new image. Then you should do the following steps for each image:

1. Image-> Image Size->Document Size-> Make the Width and Height both 50 percent, and select "OK".
2. Save for Web or Devices->Save as type JPEG with Medium quality. Earlier version of Photoshop may not have this option. In that case, just save it as a jpeg with medium quality.

You can make a macro that will do this for each image that will speed up the process.

Microsoft Paint

You must do each file one at a time. You can't drag a 2nd image into the Paint program until the first one has been resized and saved. For each diagram image, do the following steps:

1. Image->Resize - Set the Horizontal and Vertical sizes to 50%.
2. Save As-> - Then select type "jpg" as the file type.

Paint.net

This is a free program that you can download and install. It was originally written at the University of Washington, and is still maintained by some of the original authors. It is completely free, and it is better than Microsoft Paint. To get the free download, go to http://www.getpaint.net/. Once its installed, open the program and do the following steps:

1. Drag each image you want to save onto the Paint.net program window. You can drag all of the images into Paint.net, and it will create a new file for each image. You don't have to save each image before dragging in another one.
2. For each image, do the following steps:
1. Image-Resize...->By percentage->50%.
2. File->Save As..->Save as type: jpeg-> - Use 50% quality setting.