On my 1986, I was getting the ABS warning continuously at 4MPH and it stayed on. Before I could take a look at the RPM sensors, a new symptom.

The ABS warning didn't come on but when I applied the brakes, the car pulled very hard to the left as if the right front brake wasn't engaging. This happened on several test runs but now I am back to the ABS warning coming on but the brakes are engaging normally.

Any suggestions would be appreciated.

 

Sounds like your ABS system trying to compensate for bad inputs from the wheels or a wheel, and maybe that's why you're getting the warning, and pulling to the left as it applies antilock to the right.

Check and clean your wheel sensors and connectors ... wild guess left front sensor or connector is kaput. Could of course be anything else in the system, but that's where I'd start looking.

 

When the system detects a bad sensor it deactivates the entire ABS system. It will not try to compensate. Something is going on with the pump or the controller.

 

I had similar issues with my S4 ABS a few years back; tried changing the relay on the main electrical panel and while that helped some it didn't cure all. I cleaned the sensors and bled the sysem and again it helped but not everything.

Then I replaced the relays for the ABS pump that are under the LH front wheel cover.....that sorted it.

 

Sounds like the RF sensor is sitting a little too far from the tone wheel. At low speed there isn't enough signal output (hall effect) so it looks like the wheel is locked. The system will release pressure in that wheel to try and the speed back up. Thus, the pulling to the left.

 

I went through the ABS issue a few years ago. As said above clean your sensors. The best way to test them is get a test meter with a frequency counter. Hook the test meeter up to the two wires from the sensor. You can do it at the connector. Then just spin the hub. The meeter will read the counts. If you get counts the sensor is good. No counts and it is bad. Fluke makes a nice meter with a frequency counter. They are fairly expensive so if you don't have one you may want to borrow one if possible.

 

Same thing happened to me in my Versa. I installed a non-ABS hub by accident and the protective plate on the non-ABS hub, which the ABS hubs aren't supposed to have, cut the sensor right off. ABS system still works, but i have to make sure the ABS system never engages now because when it does it completely locks up FR wheel, i almost crashed the first time it happened and i'm just too lazy to pull the hub out again and get a new sensor. So the ABS system being totally disabled with a bad input isn't totally true.

 

You've got a weird ABS system on that Versa. Most that I know monitors the wheel sensors all the time and if something doesn't add up, it de activates it.

 

Do you feel a pulsating in the pedal when the light is off and the car pulls to one side?

 

I had ABS errors a while back. Since I have a RDK ecu and diag tools, I can check the signal from the 4 sensors (almost like a frequency counter). Easy to do, but I could never catch any issue with the sensor output. The ABS errors were intermittent and hard to pinpoint where it came from. So I swapped the relay. It is a special one as it has a (high power 22volt Zener diode) spike voltage protection in it. Here is a link to some info:
http://jenniskens.livedsl.nl/Technic.../MyTip1030.htm
Swapping the relay made the errors disappear.
regards
Theo
1992 928GTS, in the Netherlands

 

Yes, that is very odd. New systems look for open and short to ground. It should fail on key up and default to backup EBD only.

928 do weird things because the ABS is really old and didn't have much diagnostics back then.