mainboyd

Just like what the title says, my 4W ABS light comes on once I start the car and it stays on when I am driving.
Does anyone know whats going on and what do I need to do?

Thanks,
David

Okie-RX7

iTrader: (1)

Check all of the ABS wheel speed sensors and make sure they read the correctly 0.8 - 1.2k ohms. The front two connectors are in the engine bay, the rear two are under the bins,

mecman

iTrader: (11)

I have the same problem. Checked and replaced the four wheel sensors. That wasn't the problem. Next, there is an ABS computer in the hatch area above the driver's side wheel well. If you need one I have one for $30.

axnjaksn

iTrader: (2)

Chk your charging system and see what its charging at running....i had a the 2 pin connector come off my alternator and it was throwing 16+volts and made my abs light come on.....

Tsukuba

Thats strange but I bet anything that's what mine is doing...thx

Okie-RX7

iTrader: (1)

If it isn't the wheel speed sensors themselves, I would start at the ABS computer, unplug it and test the wires to the wheels speed sensors( page P-52 service manual). Next check the gray ABS connector on the passenger side of the car and make sure you have voltage to the pump. Unplug the connector, key the car on and test the W/R wire to the pump, it should have the same voltage as the battery. That is what was wrong with mine, the terminal had corroded. After that check the two relays on the ABS pump. If all that checks out then I would be leaning toward a bad ABS ecu.

mainboyd

thanks for all the replies!
I will start looking into all of that soon. its not going to be a problem if i drive it like that for now right?? its my DD as of right now because my actual DD broke down after 222,XXX miles...

Okie-RX7

iTrader: (1)

You should be fine to drive it, just remember you probably have no ABS. I drove mine for almost a year with no ABS and it was only a problem in heavy downpours.

mainboyd

I believe i found the problem. I checked the ABS fuse in the fuse box next to the battery (in the hood) and it looked a little corroded so i switched it out with the DEFOG fuse, for now, that was next to it that had the same V and 60A. Usually the ABS light would come on once i move the car forward in gear and after doing the switch it didnt come on but i didnt take it for a drive, I just moved it forward in gear so i will be taking it out for a drive soon to see if everything is ok.

What exactly is the DEFOG fuse for? and is it ok that i switched it out with the "bad" ABS fuse?

thanks,
David

twinsinside

iTrader: (34)

Glad you found the problem. Mine was acting up a few days ago too, but the light was on and it was "buzzing" with the key off. Smacked the relays around a little and reconnected the battery and it went away.

AzEKnightz

iTrader: (24)

sticky abs relay does that all the time. Replace before it drained your battery dead.

-AzEKnightz

twinsinside

iTrader: (34)

I keep a trickle charger on it and haven't noticed any drain (maintain light on, not the charge one) since I checked the relays.

also the car was down for about 6 months and just recently finished my rebuild and got her running again, so I was kind of expecting weird stuff like that with it just sitting there gathering dust

AzEKnightz

iTrader: (24)

That's a great idea with the trickle charger. Alot of the owner's doesnt know a simply trickle charger can relieve so much headaches =P.

-AzEKnightz

Zoolander

iTrader: (8)

Funny thing. I just got my car back from the shop and had to re-wire my A-pillar boost gauge. The body shop also deleted my rear wiper so while I was down there I decided to pull the rear wiper fuse. Got the boost gauge light to work but now the ABS brake light stayed on. I cursed the ole adage "fix one thing and something else goes" and searched and came up with this thread about the sensors. Really didn't want to go through all this. The next morning I put the rear wiper fuse back in because that's really the only thing I changed but thought it couldn't be that simple....and what does the rear wiper fuse have anything to do with the ABS system? Lo and behold: the ABS light turned off after it initially lights up.....just like normal.

Thoughts?

mainboyd

the ABS light came back on... so i just disconnected the battery and took the two relays off the ABS pump checked to see if they are still good according the manual (had no clue what i was doing) and then put them back in, reconnected the battery and gave it a test drive and so far the ABS light has not come back on. I hope my ABS brakes still work though, how would i know if they do?

$lacker

iTrader: (9)

Drive fast, stop quickly

mainboyd

hmmmm... lol i knew that was going to be said but is there any other way?

billyboy

Short of hooking up to a dealer's ABS diagnostic tester, probably not.

That's been brought up several times in the past, if you strain you eyes and look on the far right of the diagram below, you can see the power supply going into one part of the ECU via ignition switch and wiper fuse....95 schematic.

Nataphen

iTrader: (6)

Thanks for all the posts, I'll start testing things Monday morning. Rotary Performance also told me a while back that sometimes you can clean the wheel speed sensor connections to fix this, but I haven't gotten around to working on the ABS issue until now. I'll report back once I find my problem in case it's a help to someone in the future.