Abs Help

[gp1200x]

I'm trying to fix an ABS problem on my 99 RX.

The light is on as soon my the car starts...even while in park before any movement even occurs. I hooked up a pretty good code reader to it and it shows no code error or malfunction. This is a pretty good unit (Actron) so I'm surprised that it says no malfunctions occurred with the vehicle and no codes are pending. (I'm trying to see if I can review all the PID data still.)

I checked the 60amp fuse # 45 and it is okay. Any other ideas to look for? Somehow I have to get a reading to tell me where the malfunction is...like maybe a broken sensor wire.

I haven't flushed and bled the brakes yet but will in a day or two when I change the pads, which are not that bad yet but don't like the pedal....spongy.

Looking for my CD manual..hopefully it will have a schematic for the wiring.

If I need to get this to pass inspection will it fail if the ABS light is on?

If so ..... if I yank the dash bulb I don't think the inspection center will know since my OBD reader doesn't show a problem....so how could they be able to tell without the bulb lit?

Thanks

[lenore]

You might try unplugging and plugging back in the connector to the top of the ABS unit, maybe corroded. That fixed my Ford F150 ABS light.

[wwest]

Top off the brake fluid reservior...

[mikey00]

Top off the brake fluid reservior...

It's the "brake system warning light" that comes on if the fluid level is low. If the "ABS" light is on I don't think adding fluid is going to do much.

[gp1200x]

I found my problem. I ordered two ebay manuals for $10 and one had a great writeup on the ABS and I was able to troubleshoot the bug. Bad connection on front driver wheel sensor (ABD error 32).

For future help...tips..

The ABS system on the 99RX (don't know about later years), is actually pretty simple. Front and rear brake lines run to the ABS unit and it connects to the wheels. ABS errors can be found by shorting a wire and counting the ABS light flashes.

Bleeding the ABS is exactly the same as a standard non-ABS setup...mast. cyl (if needed), then RR, RL, FR, FL.

Think of the ABS as simply a T connection on each line to each wheel. The T connector is opened and closed by a solenoid for each wheel run. Activating the solenoid (by the computer) releases the hydraulic pressure by allowing it to follow through the T to the offshoot, thereby allowing the brake to release and the wheel to turn. No air is introduced into the system. The excess fluid in the offshoots is pumped back to the brake reserve and recycled. You do not have to worry about it when bleeding the brakes. Very simple design. If the computer detects any malfunction, the entire ABS is disabled, therefore no solenoids can activate.

Failures are listing in the manual and they can be read via the ABS light itself in the dash. They can also be reset. I spent about three hours (half of it pulling panels to get to the connections) and was able to understand, diagnose and find the problem and fix it with no parts, although I may replace the sensor since it is now modified to work.

Any backyard mechanic can probably repair this system with simple tools and a meter. A scope is really not required since if you get to that point, you will be spending major bucks on a new ECU. The ring gears seldom go bad unless physically damaged such as a broken tooth, which would require a CV replacement.

I probably saved $500 -$1000 bucks since I know they would have done what I did and charged me top dollar to determine the failing component. A new sensor is about $200+, so I will not be buying one!

Believe me...it is easier to fix than you think. I was able to trace the failure to the bad wire with just the $10 PDF manual on EBAY.