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Discussion Starter #1 (Edited)
How-to: 2004 STi ABS sensor troubleshooting - installation guide

Disclaimer:
I'm not a mechanic. I have absolutely NO training in that field. What I know, i learned by doing mistakes. I can't be held accountable for any/all of this how-to. Use are your own risk :)

Hola everyone :) Been a while since i've posted. Anyways, on with the how-to!

Problem:
So you have your ABS light brightely lit up in your dash. Your DCCD is disabled and it's flashing green. WTF is going on?

How to read the ABS code:
Locate those green connectors above your feet, located up where to clutch is. There is a small bundle of wires that are attached to those green wires. Those are the ABS diagnostic wires. Prepare to curse a lot just locating this connector.



Plug in ONE of the prong connectors to terminal 6. It won't be easy because the space is limited down there, so that flashlight will be useful :)

Put the key in the ignition and set your key to position "ON"

The first code you'll get is 11. The ABS light will flash a long flash, then one short one. Follow carefully, the trouble code is next.

ABS DTC list

11 – Start Code, DTC is shown after start code, Only start code is shown in normal condition

Abnormal ABS sensor, open circuit or voltage too high
21 – front right ABS sensor
23 – front left ABS sensor
25 – rear right ABS sensor
27 – rear left ABS sensor

Abnormal ABS sensor, abnormal ABS sensor signal
22 – front right ABS sensor (passenger front)
24 – front left ABS sensor (driver front)
26 – rear right ABS sensor (passenger rear)
28 – rear left ABS sensor (driver rear)
29 – any one of four

Abnormal solenoid valve circuits in ABS control module and hydraulic unit
31 – Front right inlet valve
32 – Front right outlet valve
33 – Front left inlet valve
34 – Front left outlet valve
35 – Rear right inlet valve
36 – Rear right outlet valve
37 – Rear left inlet valve
38 – Rear left outlet valve

41 – Abnormal ABS control module
42 – Source voltage is abnormal
44 – A combination of AT control abnormal
51 – Abnormal valve relay
52 – Abnormal motor and/or motor relay
54 – Abnormal stop light switch
56 – Abnormal G sensor output voltage
The rest of this guide will fix code 25. Which is the one I got. When installing my new suspension I "yanked" on the ABS sensor wire. It broke ...

Testing your new ABS sensor before replacing it:
So let's say you picked up a used sensor for about 30$ (sweet!). You want to test it out to see if it's working.

This is a REAR abs sensor.


Set your multimeter to read OHMS.


Put the red and black probe on each of the metal pins inside the white plastic plug. We are reading if there is a resistance, thus knowing if the sensor is ok.


You are getting a reading? Good! That ABS sensor is good to go :)



Install the new sensor (rear sensor):
Like I said earlier, these instructions are for installing the rear sensor (passenger side)

Start by removing both 12MM bolt (one of each side of the rear seat)


Pull up and towards you. Remove that seat. CAUTION! if you don't want to scratch that precious paint while pulling it out, watch out for those massive U metal hooks on the seat.


Locate the rubber plug that the ABS sensor is connecting to.


A better view of that plug. You can push this one out since we are replacing the whole sensor assembly.


I won't go into details, but jack up the car, secure it and remove the wheel. You can find more information in this how-to by Austinpike http://www.iwsti.com/forums/how-ins...ots-guide-getting-your-car-up-jackstands.html

Tricky part alert! Removing the ABS sensor ... Patience is a virtue.
Locate the wheel sensor/ABS sensor and remove the 12mm bolt that's securing it.
Pry at it, grab it with a pair of pliers, do whatever you have to do to pull it out.
The sensor is located behind the wheel, here a somewhat good picture of it.


Next 12mm bolt is located on the control arm, here.


A better a look at that bolt:


Now, follow that wire, you will see ANOTHER 12 MM bolt. You really need to go under the car for that one. I couldn't take a picture of that one.

Replace everything in reverse when you install the new one. No need to clear the ABS light, once the system detects it can read the sensor again, the light will go away.

Hopefully this was helpful :)

Cheers!
 

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Discussion Starter #2
Re: How-to: 2004 STi ABS sensor troubleshooting guide

My car is a 2004, I drive year around so yeah, it's a wee bit rusted :) The body is intact btw hehe.
 

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GREAT INFO.

Thanks for sharing.

Its nice Subaru made it so you can read the ABS codes without having to have a $3000 scan tool.

That's so 1980s. :)
 

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Discussion Starter #6
Anyone have any idea why the light isn't kiting up, and not working?
Do you mean not "blinking" out the code? Double-check the connections to the ABS fault terminal like I illustrated in the picture :)
 

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Update*
Went to stealership and found out that the sensor wire for lh wheel speed and throttle wire were broken. Also found out that the abs module was bad... As for the light, it's burnt out or not working for some other reason, but after 12 hours (only charged for 3) I decided to research a cure for the light on my own. So if anyone has some insight how to fix that I'd be forever grateful.
 

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My ABS light has been on for a while now. I cleaned the ABS sensor a while ago and the light went off but it eventually came back on. Just brought it to the Subaru dealership and had it checked out. I am informed I need a new ECM ABS Module? What the Sh*t is this? I am told it will cost me about $1000 to replace.

Does anyone know if I have to buy this ECM module or can I just get away with turning off the light and or buying a new ABS sensor??

Please any help would be GREATLY appreciated.
 

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My ABS light has been on for a while now. I cleaned the ABS sensor a while ago and the light went off but it eventually came back on. Just brought it to the Subaru dealership and had it checked out. I am informed I need a new ECM ABS Module? What the Sh*t is this? I am told it will cost me about $1000 to replace.

Does anyone know if I have to buy this ECM module or can I just get away with turning off the light and or buying a new ABS sensor??

Please any help would be GREATLY appreciated.

The ABS electronic control module is located passenger side underhood. The unit with all the brake lines coming out of it. What is/was the codes that set? Is that on the dealer repair order or are you able to pull the codes?
 

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My ABS light has been on for a while now. I cleaned the ABS sensor a while ago and the light went off but it eventually came back on. Just brought it to the Subaru dealership and had it checked out. I am informed I need a new ECM ABS Module? What the Sh*t is this? I am told it will cost me about $1000 to replace.

Does anyone know if I have to buy this ECM module or can I just get away with turning off the light and or buying a new ABS sensor??

Please any help would be GREATLY appreciated.
You can find them on eBay for around $50 used, which beats the dealer price. BTW that's the price I was quoted as well. Changing the module out is straightforward and took me 45 minutes, just be careful not to bend the brake lines anymore than necessary, it will make installation of the new part much easier.
 

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Bumping this because I need some help. I have attached a picture of the connector that I assume you are talking about. But what are the prong connectors that I am supposed to plug into the terminal? Just not sure what you mean by "prong connectors". If anyone could help that would be great! My ABS and DCCD lights are both on. Although the DCCD is not flashing green, just solid red "DCCD" and I have no control over it. Thanks again.

 

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Ah, I got it. For anyone reading this in the future, the prongs are connected to a red/black wire that is looped back into the group of wires that that connector comes from. Mine was a pain to get to, it was looped extremely far back up. But I got code 44, which is "A combination of AT control abnormal" Anyone have any info on what that means? I think i'm also getting 51 – Abnormal valve relay and 21-21 – front right ABS sensor
 

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bump for the helpful post. the other day, i pulled slowly out of my garage turning the wheel as i exited and the ABS light came on as well as grabbing on the front right. it like the sound and feel the diff makes when it's locked and you turn too tightly. or as if one one brake was grabbing. this only happens when going slowly. i just got DTC code/s: 21 (front right abs sensor; consistent with what i was feeling) and 56 (abnormal g sensor output voltage). i'll get a replacement abs sensor but anyone else had a g sensor go bad?
 

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bump for the helpful post. the other day, i pulled slowly out of my garage turning the wheel as i exited and the ABS light came on as well as grabbing on the front right. it like the sound and feel the diff makes when it's locked and you turn too tightly. or as if one one brake was grabbing. this only happens when going slowly. i just got DTC code/s: 21 (front right abs sensor; consistent with what i was feeling) and 56 (abnormal g sensor output voltage). i'll get a replacement abs sensor but anyone else had a g sensor go bad?

Who are you?

:rofl:


Familiar member. Thought you were out of the game.
 

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following up: i got a used front right abs sensor off ebay and installed today. sheesh, this was the easiest repair i've done on this car; literally 5mins once the wheel was off. the bolts and sensor came out without the slightest hitch; i was expecting the worst. the ABS light is off so that 56 code i was getting must have been spurious or related to the 21. all good. thanks again OP.

i'm still puzzled about why i was experiencing that "brake grabbing" when turning the wheel sharply and rolling slowly. it couldn't have been the abs since my foot wasn't on the brake. (isn't "brake pedal pressed" the first condition in the logic of the abs?) any thoughts?
 

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Re: Re: How-to: 2004 STi ABS sensor troubleshooting - installation guide

following up: i got a used front right abs sensor off ebay and installed today. sheesh, this was the easiest repair i've done on this car; literally 5mins once the wheel was off. the nuts and sensor came out without the slightest hitch; i was expecting the worst. the ABS light is off so that 56 code i was getting must have been spurious or related to the 21. all good. thanks again OP.

i'm still puzzled about why i was experiencing that "brake grabbing" when turning the wheel sharply and rolling slowly. it couldn't have been the abs since my foot wasn't on the brake. (isn't "brake pedal pressed" the first condition in the logic of the abs?) any thoughts?
I don't think your feeling the ABS. I think your feeling the affects of the DCCD not working.

I believe when you have ABS issues it can affect the DCCD. I'm having a rear diff temp light now which I believe is just a bad ground and ABS light. I experienced the exact same thing you are, clunking/jerky motion when driving slowly and turning sharply. I'm attributing this to the fact that the DCCD is somehow disabled because of the ABS issue. Why the two are so closely tied I don't know.

Sent from my XT1080 using Tapatalk
 

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doh! of course. my understanding is the dccd uses wheel speed to do it's thing so it would make sense for it to drop into locked mode with an abs wheel speed sensor failure. thanks.
 

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bumping an old thread: I am trying to locate the diagnostic plug and have the dash apart under the steering wheel. My green test connectors have been located. They travel into a larger harness is the plug within the bundle of those wires or is it its own plug hanging loosely somewhere tucked up and I have yet to find?
 
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