Here is the problem,

Since a couple of months The ABS light comes on sometime after speed reaches 20 km/hr, sometime I can drive a distance of 20 km at 100 km/hr then it is back on again. This happens almost everytime I use the car. My wife also drives it.

I did clean the sprokets and sensors at the front wheels. There is no wheel sensor at the rear wheels so I suspect rotation signal may be picked up at the differential(?).

How can I test front wheels sensors?

What is the price of each?

Are there good quality after market replacements like say Bosch?

Is it dangerous to keep driving with ABS light on?

For a couple of months I am driving and do not notice any alarming behavior when braking.

If I am missing only the ABS brake control, I can easily live without. I always hated the way ABS works. I feel I can do a better job myself and stop faster; is it not what is better(stop faster)?

I can understand that some people may not be able control the brake pedal to keep the car on the road but ABS is imposed to everybody. No flip OFF switch.

Thanks for your replies.

Have a look at later thread on 740 ABS.

Rear sensor wire is flexed by axle moving and certainly was the problem with my ABS. Worth a look.

AndyT wrote:

> Rear sensor wire is flexed by axle moving and certainly was the

> problem with my ABS. Worth a look.

Thanks for the reply,

I will certainly go there and see if connector is the culprit.

The thing about ABS is this: It can pump the brakes at one wheel at a time (front wheels each in the case of 240s, and the rear axle as one). You can never do that with your feet.

Tests always show that stopping distance is decreased in all conditions except in deep sand or loose gravel where it is actually beneficial to have the material pile up in front of the tires for maximum stop. On dry, wet, or icy pavement or other hard surfaces, ABS always stops faster and lets you steer while braking, as opposed to steering/braking seperately, as one has to do on non-ABS cars when the wheels lock.

With abs light on you don't have abs. brakes should work as normal/non abs brakes. One note...abs brake systems are often biased to the rear, so if you run w/o abs, the rear often locks first. That's why with abs it's important to hit the brakes hard and hold them...just cuz you feel abs pulse doesn't mean you're at max stop...it's just the abs pulsing the rear brakes!

AFAIK the sensors aren't testable by average guy...but you might want to disconnect the connectors at the front inside the engine compartment and clean them well and reconnect them with a slight dab of conductive grease like OxGard or something. Not too much or it will short the connection.

If that doesn't fix it, it costs about $180 parts and labor to install a new front wheel sensor. Or you can buy one and install it yourself...the big problem is getting the old one out because they're generally corroded in there pretty good and the sensor is destroyed by removing it.

The ABS sensors on this car are the inductive type. When the wheel rotates, the tonewheel generates a AC-voltage in the sensor. The resistance of the sensor is normal around 1000 ohm's (resistance of the spool). You can measure this with a normal multimeter. A common failure on this type of sensor is interrupted circuit. The windings are from very thin wire (0.05 mm), and if the sensor is not perfectly sealed, water gets in and the wire corrode.

If the sensor is from ATE (I think it is Bosch), I can gife you more information if you mail me the ATE partnumber (something like 10.0711-1077.3).

I am working in a ABS-factory (from ATE).

Jan,

Sorry I can't reach to you by email. I get this post that says"email address has not been specified...., must specify address in mail and group preferences".

I don't know were to find this page. Brickboard does not have it at fist look. Whatever.

Yes, I will do some homework and would like to communicate later with you.

Thanks.