In an attempt to help another forum member that had both his DCS and ABS lights remaining on, I came up with the follow for him to use as a reference.
Keep in mind, I am certainly no expert, and some of this comes from experience and some is a compilation of various things I have read and heard of that turned out to be the issue.

If anyone with the issue solves it by use of this thread, then please let me know and eventually I will put these in order of most likely possibilities when we get enough of them.

First, the reset procedure for the DCS/TCS is as follows and is different than the ECU reset(or any other reset).
This is the same reset that you need to perform after disconnecting the battery for any length of time. Having said this, know that if you have driven the car and made fairly sharp turns it should have gone off on its own, but you might want to try this reset for the hell of it.
More importantly, after anything you do to try and fix this issue you may have to reset to see if it has been fixed.

Here's the reset:

1.) Turn the ignition switch to the ON
position. <--- This doesn't mean start the car!
2.) Turn the steering wheel fully clockwise,
then turn it fully counter-clockwise.
3.) Make sure the DSC OFF indicator
goes off.
4.) Turn the ignition switch to the OFF
position, then turn it to the ON
position again.
5.) Make sure the TCS/DSC indicator
light goes off.


Now some questions:

Are you using the right size tires and all the same size, brand, and tread pattern?

Is one tire really worn more than the others?
Even a small difference in one(or in the tire pressure) can actually lead to this...............but not really all that common.

If either of the above are true(especially the first one).....it can cause these lights!



Some possibilities and checks:

In no particular order(right now).

1.) Make sure none of the wires leading to the sensors have been compromised. Also check the connectors for good secure contact/connection. Have seen many times where due to road debris or when changing out suspension parts that wires have been cut by accident, sensors damaged, or connectors unplugged.

2.) It can always be the sensor itself, just take off the wheels and make sure the sensor is snug, have someone watch your dashboard while you fiddle around with it, if it happens to be loose on a particular side the light on the dash should go away. The sensor is on each hub and is connected with a singular black wire that runs from the body to the sensor(behind the rotor).

3.) You can do a RESISTANCE CHECK by: Disconnecting the sensors and checking with an ohmmeter for 0.79 - 2.2k ohms resistance.

4.) Brake light switch could be sticking on the brake pedal. I read where someone replaced it after doing #3 above as he read 4.4 - 4.7ohms at one of the sensors.

5.) Under the hood in the fuse box in location #7 is the ABS/DCS fuse. It's a 60A and you should check this!

6.) You also need to check #13 a 30A in that same engine bay fuse box.

7.) In the cabin fusebox(by drivers foot), check #10 which is a 7.5A

8.) Alignment can cause this issue believe it or not.

9.) A burned out third brake light. Of all things!

10.) Unfortunately I read that the damn PS connectors being dirty can cause this as well. WTF?

11.) Oh…I know one………you didn’t stick an LED in the third brake light position did you? That can cause it! I went through that one myself! Some people don't need a load resistor and some do, the value I've seen recommended is........a 2 watt 150 Ohm wire wound resistor. There are some DIY's on how to put it in if you need to do so. Easy to tell, take out the LED and replace with normal bulb and see if issue goes away!

12.) Get your alternator checked out and make sure it’s not over-charging as this can fry the module.

13.) Keep in mind if the center position of the steering deviates, the DSC may also not operate correctly because there is a sensor in the steering which detects driving conditions. (See reset above, but you might want to check the connector)

14.) Cut or shorted third brake power wire. This one can pop the 15A stop fuse in the engine bay, so check that!!!!

15.) Actually have been cases where just a shorted tail light and/or brake light has caused this and also blown that same 15A stop fuse in the engibe bay.

16.) Not likely, but the actual switch itself could be bad.


If you have any direct knowledge of anything else, let me know and I'll add it.

 

good stuff thanks Mazurfer

I have first hand experience of the lights coming on because of worn/uneven tires

 

Thanx for the info.Not sure if you were answering me directly or not but i posted this question recently. Will test it out today

 

No, I wasn't but let me know if it helps or you find anything..........even if it's not listed here.

 

Edited first post with some new info and changed the title!

 

I had dsc light & traction control system light problem on my 04 Rx8 MT.

After reading Mazurfer post, i got everything sorted out:

My problem was solved by #11 possibilities and checks.

Thanks Mazurfer

 

I checked #5 6 7 11 and did the reset but it doesn't work for me. I take my 8 to Mazda dealer and they asked for 108 USD to do the check on;y. That's expensive! I may try to do #1 2 by myself later.

 

Did you have any unusual event that caused this light to come on?
Examples..........
Change a tire?
Rotate tires?
Hit something?
Change any bulb?
Lots of rain perhaps?
Disconnect the battery for any reason?
Anything else unusual that you may have done?
Do you have TPMS in your wheels? If not, have you checked your tire pressure?
What kind of tread life do you have left? Is one worse than the others?

 

When I first bought my car I had this issue. The guy was running gforce tires with goodyear on the back. They were the same size, but the front tires were soft, and the rear tires were a stock tread. I replaced them with michelin 245/40 18 and then reset the system doing the steering wheel reset and the problem went away.

Also he was running a stock style tire on the rear but it was 255/40 18 and the fronts were 225/45 18. I dont know what he was thinking but it was mess.

 

Today i had this happen while driving. Restarted the car and all was fine, didn't happen again.

225/50/17 front, 225/55/17 rear, been using this setup for a month now without issues. My driving style has not changed, hoon at the sight of snow!

 

Just what I was lookin' for, Cheers> Have the same problem for 2 weeks now, the lights are never on when Im anyway close to my local dealer for them to check, i brought it in when they started first, but they told me there was not fault and the done a visual check on all the sensors. So I'm gonna start on No1 and work my way through them all. Let you know which one, Sooon. Oh I did have the battery outa it for about 2 weeks, when we got snowed in.

 

i just had subwoofers installed by best buy, ever since my DSC light has been stuck on. the reset does not make the light go away. has anyone heard of this happening before? i'm thinking best buy knocked a wire out of position

 

I tried several check listed above but no one work for me. I gave up and send my car to dealer. They told me sensor behind my steering wheel is out of order and need to be replaced. Finally, it takes me 600 dollars to fix this problem!

 

I always found it very interesting.
how do you turn the steering wheel without the engine running. its already heavy with PS, without PS its almost unturnable.

 

After trying all the points above,now the centre console have given up, so i have given up and brought the car car to the local Mazda Steelership. Who have told me they dont know what the problem with the centre console is and the error codes for the lights on the dash are , speed wheel mismatch + censor power supply failure, they say the speed wheel mismatch is because i have fitted the wrong size tyres on the rear, I told them I have these tyres 18 months or so, i dont see why its only become a problem now I have 225/45 r18 Front and 225/40 r18 Rear, these are the same spec as when I bought the car 4 years ago. They have said they dont know then, just fit the sames size tyres front and rear and the problem will fix its self.

 

yes, RX8's stability control doesnt like different tires.

 

I am running 245/35/ZR19 Cooper Xeon 2XS front and 275/30/ZR19 Achilles ATR Sport rear without issue. BUT, the fist thing I will do if I run into this issue is replace the tires.

 

Yeah, I'm not running stock size and staggered and I don't have it either.
Just be advised that it could make you more sensitive.........especially if you get uneven wear in the the future.
Funny thing is, it's been confirmed by several that had replaced just one tire and that it caused it. Same size, but different brand and tread pattern!

 

Thanks Surfer! It appears my 3rd brake light hasn't worked since I bought the car. I changed the bulb, to no avail, so, I went looking for other causes. I put a rock on the brake pedal, so the lights would stay on, and went to the trunk, pulled the carpeting back and started wiggling wires around, still didn't work. So, I took the liner out of the trunk again, and removed that harness that's inside the trunk lid. Pulled the contacts away from the bulb on a spare I had, and touched it to the connector inside the trunk, tada, there's power, there wasn't any power on the opposite end(end going to brake light)
So, it's obvious it was the short harness mounted to the lid. I found a break in the wire. It was right where that grommet attaches to the trunk lid. If any of you guys have issues with this, and your 3rd brake light doesn't work, start there

 

So..............#14 was your issue?
Wondering how you developed a short to trunk lid? Is this an area that you had previously messed with on some occasion?

 

Nope, I'd never taken it apart before. The wire was broken, so there just wasn't any power getting to the bulb. It was in an area that sees a fair amount of flex, and I guess it just finally broke.

Yes, #14

 

I am an occasional lurker on this board, and hope to have a track day issue sorted if possible.

I have the problem of the Brake, ABS, and DSC lights coming on and staying on during track sessions. I have seen many variations of this problem described on this board, but no clear picture as to why this happens on my 2005 RX-8 GT *only* under hard track use. The car is otherwise amazingly reliable and a joy to drive as a touring car. But in two seasons of track sessions this one issue hasn't gone away.

The only changes from stock are fresh DOT5.1 brake fluid, tires (Goodyear Eagle F1 All-Season 235/40ZR18), and now Carbotech XP-8 pads all around. I tracked the stock Dunlops with the stock pads for most of a season. Brake fade happened around the same time as the light issue. With the new tires and pads, there is no evidence of fade, but the lights still come on.

The lights clear when the car is turned off and back on. But they will come back on quickly if
the tires and brakes are still heat soaked. I know a few other forum members track their cars
with great success and not a lot of hardcore modification. The truth is out there.

The treasure trove of info here already helped me with the climate control issue,
so I am already in your debt. Thanks in advance and happy revving...

 

I hav problem with my ABS sometimes it come and some it goes automatically, i also check the back light it's ok, so what i will do now pls need help...

 

Go through first post.....especially under "now some questions" since you really haven't said when this light appears and then disappears. Based on your loose info, it could be one ofg these items. If not, then look at everything in first post.

 

ok thnx....