"Anti-Lock" light and 3 ACD lights
 

posting here because it is track related, but i may cross post since im not sure how common this is.

it was very hot at the track this weekend. While trying out some deeper braking to find some time on saturday, i managed to engage ABS kinda of hard, but quickly released the pedal a bit and all went back to normal. I believe this happened in either the 3rd or 4th and final session of the day. When i started the car for the first session on sunday morning it went through its normal lights on the dash check but this time the "anti-lock" light remained illuminated, and within a few seconds all 3 ACD lights lit up. As far as I know when all 3 ACD lights go on the diff sets itself to full open, and the potential of having no ABS wasn't a big deal to me so I finished the day without issue.

useful info - '06 Evo 9, maxxis RC1's, stock calipers with racing brake stainless pistons, Hawk dtc60 pads.

I visually inspected 3 of 4 abs sensors at the hubs and saw no visible damage, but im going to take a closer look when i swap wheels today or tomorrow. I attempted to read the abs ecu with evoscan but for whatever reason i couldnt (my laptop was nearly dead, so that may be it, and i will try again when its charged).

It was so damn hot and slick on track on sunday, i'm not 100% sure i didnt have abs. At times the car acted like it did and at times it didnt, but this may have been because the bias to the rear is all screwed up now...


has anyone ever run into this? any thoughts on diagnosis/resolution etc would be greatly areciated

ACD lights on, means an ACD issue. If it was just the ABS having a problem, you would only have the ABS light on.

so i would have also thought that, but out of the evo crew in my region im actually not the first person to have this happen. i have had zero issues with either system previously, and the ACD pump is not original as it was replaced after a small accident a few years ago.

im not super well read up on how the acd functions, but i sort of expected that wheel speed readings would be involved? i can however say that the "clawing" feeling that you get when digging out of corners was definitely gone....

I ruined my front wheel speed sensors because I forgot to zip tie the wires out of the way when I removed the OEM dust shields, they all melted through. Only the ABS light came on.


The quickest way to figure it out is to see if you have ABS codes. Page 6 tells you how to pull codes for the ABS by grounding pin #1 of the OB2 connector, dong the proper key/brake pedal cycles, and counting the flashes of the ABS light. It kind of requires two people to do it.


http://evoscan.com/manuals/Evo9/GR00002900-35B.pdf

yeah i was reading that evoscan pdf.

there was mention on lancer register to just jump pins 1 and 4 on the obd plug so i did and got the following...

ABS:
code 32 - longitudinal g sensor system
code 42 - front left solenoid valve system

ACD:
code 51 - longitudinal g sensor system
code 52 - longitudinal g sensor system

so it looks like they may be related.

Yea, possibly. I don't see how the G sensor would be used by the ABS. I thought only the ACD used it, same with the steering angle sensor.


Thanks for the tip on jumping pin 1 and 4. That's way easier than the process the manual makes you go through with cycling the key and pressing the brake...LOL

from the abs manual pdf:

it appears the actual g sensor is located near the handbrake, so ill start there. that pdf manual has some very good trouble shooting instructions.

well...MAJOR EFFING FACEPALM on my part.


as i typed that last post, i realized a very likely cause. due to seats and harnesses i obviously dont have the armrest in the car, which leaves the g sensor exposed. the buckle of my harness drops down into the are of the sensor all the time.


right after i wrote that post, i walked down into the garage, leaned into the car, and plugged the damn g sensor back in...


problem solved.

Hahaha that is awesome! Nothing beats a simple fix like that. Love the way you went about pulling the code. Its nice when things come together like that :)

Nice. Glad it was an easy fix. I'm sure those sensor's aren't cheap. Maybe consider building a cover/guard for it. Or being more mindful of where you toss the harness when you take it off...lol

trust me, i was fearing i needed a new hydraulic unit and im guessing that would be no where near cheap.

yeah im gonna need to find a way to cover the sensor. i try to carefully place the buckle, but sometimes it falls off my lap when i pop it open.

good read, lol

Hahaha, CLASSIC! Pretty sure we all do things like this at some point.

gotta take the easy fixes when you can, and be able to laugh at yourself :lol:

one of the perks of the crazy crap we do! lol

I've been having the same issue. Here's the video (after I shorter pins 1 and 4)-
As I understand error codes 12 and 22 have to do with the front left sensor so I've ordered a replacement sensor. But why is the ACD not showing a fault code?