96 Legacy L Wagon - 2.2 AT with ABS codes 21, 23, and 27

[haugenlee]

There are loads of ABS topics on here, and I have dug through many of them. They are tough to search on this site, as it won't search words with four letters or less. (ex. ABS, any code numbers, the word 'code') So, I might be discussing something that has already come up.

 

After a lot of digging around, I finally found the diagnostic terminals under several layers of electrical tape and check the codes stored in the car. I came up with three (well, at least three...I'll get there) 21, 23, and 27.

All of them are "Wheel Speed Sensor Open or Short Circuit" for both front sensors, and the rear left.

 

Now, my question is, what is the likelihood that the rear right sensor would throw the same code? It seems to me that the the 'Open or Short Circuit' must be happening at the ABS computer to throw the same code for all three.

Does anyone else have thoughts on this? Where I should start looking?

 

A guy I know has agreed to run the codes at a dealership (no cost, thankfully) because I couldn't find the diagnostic terminals. Would his code reader (I assume it is one that can read through OBDII) retrieve more than just three codes?

 

 

 

 

 

I am far from being a mechanic. Sorry if I missed any other important details. I am learning as I do with hopes of keeping this car around for a while.

Edited January 14, 2014 by haugenlee

[haugenlee]

I brought it in to have the codes read, and the scanner couldn't read them.

I am a bit stumped. Should I assume it is the ABS unit/module?

[1-3-2-4]

You have to look for the ABS connector under the dash, you cant get a code reader to scan them because it's a separate system

 

You can clear the codes to start fresh but if the same codes come up again then you know what you need to have fixed.

Edited January 17, 2014 by 1-3-2-4

[haugenlee]

I did that. That's how I found out that the codes I have stored are 21, 23, and 27. I was just hoping we could pull some more or more detailed codes with a reader. He usually reads ABS codes with it. I figured we might not get something from it, but I thought it was worth checking.

 

I just am looking as to where to start with the three codes that I have right now, as I don't know what to have fixed given that three (probably all) of the wheel speed sensors say they are bad. I don't think that would be the case. I assume the circuit trouble might not be happening with each individual sensor, but maybe in the module instead.

 

I will try resetting the codes to see if they come back. I haven't done that yet. Not sure why I didn't think to do that. Thanks for the idea.

[1-3-2-4]

Yeah resetting is a good idea to do, when I got my car I had 3 codes as well, and one of them I remember saying it was the G-Sensor.. I reset the codes and the only code that stuck was the right rear ABS sensor, I finally replaced it this past summer as I finally scored a good price on it (Right rear seems to be the most $$) and turns out the ABS sensor wire where the little boot goes had a short in it. But the effect it had on the car was crazy, the brake pedal would get rock hard solid or the ABS will work for a few miles then just stop or not work at all upon starting the car.

[haugenlee]

I got it reset. The light was on when I turned the car on again, but when I ran the codes none showed.

After driving for a few miles I checked again. Just 27 this time - Rear left abnormal wheel speed sensor (open circuit or input voltage too high).

I found a document that gives a step-by-step of what to check for ABS codes. If anyone needs it, let me know. Looks to be very helpful. Supposed to have a new layer of snow and a lot of wind tomorrow. I will pull it in out of the cold to check some things out to see what I can get going.

 

Thanks again, 1-3-2-4, for getting me on that path. This looks a lot more manageable now.

Edited January 18, 2014 by haugenlee

[Fairtax4me]

You need the Subaru Select Monitor in order to read ABS codes with a scanner. Not even the new Snap-On Verus wire-less scanner we have at school will read ABS codes on a Subaru. At least not through the OBD2 port on my 96.

 

Wheel sensor codes are almost always because of a damaged sensor or wiring. If you have any rust on the knuckles the sensors can be crushed internally due to rust around the housings. Also the sensor tips wear over time and the gap between the sensor and tone wheel prevents the sensor from reading properly.

 

Check the sensor tips for wear, and check the tone wheels for dirt/grease buildup between the teeth.

[haugenlee]

Thank you.

I will give those things a look. Judging by how tough the sensor and cable look, I bet I will have to replace it. Hopefully it is just mucked up and I can clean it up to get it back on track.