Lexus/Toyota Mechanics

[Sal Lubrano]

If you have had experience with a 1999 RX 300 could you please give me some help. When I come to a complete stop while turning in either direction the pedal vibrates which is the ABS activating. This is the only time it happens. I have cleaned all the sensors and checked all the reluctor wheels and they are not cracked between the teeth. I have also used a meter to check the resistance of the sensors two front were 1.5 and 1.6 on a 2k scale and the two rear were 1.06. There is NO code. The tires are really close to brand new and poperly infated. In order to drive safely I have pulled the Relay so the ABS does not activate and the problem is gone but I do need to repair the ABS system. Does anyone have any ideas where to look next. . Really don't want to give the dealership the money since I know I can fix it if I knew what the problem was. All help is very welcome.

 

[DailyDrifter]

Still trying to troubleshoot this thing huh? If I remember I will talk to a guy at work about your problem.

 

[Sal Lubrano]

Yes, I am still trying to figure out the problem. If you remember and it is no trouble. It is greatly appreciated. When something goes wrong with this car it is never easy to figure out the problem. Thank you.

 

[wile87]

sounds like one of the front abs sensors is signaling that your locking up a tire when your turning and braking.

 

[wile87]

RX 300 Pulsating Brake pedal - Club Lexus Forums
got this from a lexus site. don't know if the link will work but you can look it up on the site.

 

[Sal Lubrano]

I have tested the resistance. The two fronts have the same value and the two rears have the same value. Which leads me to say they are good. I have also checked to make sure the ends of the sensors sill stuck to metal objects to make sure the magnet is still good. If it was any other car I would just change the sensors but this car is all wheel drive and only Lexus/Toyota makes them and they are $225 a piece and that is with a large discount. Scary how much money parts are for import cars. Like I mentioned earlier it only happens just before the car stops. I can use the brakes is a turn and they work great. Thank You for the help everyone.

 

[wile87]

ABS Sensor problem?? - 99 RX300 AWD - Club Lexus Forums
try this one to

 

[Sal Lubrano]

Thank you. I have read every post on that board and no one really posted how or if they ever fixed it. Many mention broken tone rings but I have looked at all 4 of them on this car and they look good. I have even made a post on that board and nothing has helped me find the problem yet. Lots of good advice but still nothing has hit the nail yet.

 

[gunslinger]

Does it have VSC?

I have had one RX300 engage the ABS system because the steering angle sensor was bad, and it thought the vehicle was in a slide.

Also check for rust build-up under the sensors themselves. I have seen rust push the sensor away from the tone ring enough to decrease the voltage generated by one or more of the sensors.

Also check the tire sizes to make sure that they are the same size and tread depths and make sure that they are close to each other.

If you have access to a lab scope, you can check the sensor signature on each one too.

 

[klrv6]

If you have access to a lab scope, you can check the sensor signature on each one too.

Yes, while rotating the wheel with a scope hooked up, take a hammer and start tapping the suspension You may see a spike that otherwise would never show up. I've seen a few ABS issues diagnosed only this way. I guess you could pull it off the car and stick it in a vice too. Not much fun though.


Also rotate the tires and see if it changes. Does it do this in neutral or gliding down hill?

 

[Sal Lubrano]

Steering sensor !!! Yes it does have VSC. That sounds more like the problem. Do you know where the steering sensor is on the car? I am going to check that out. I will have to chack and see if it does it in neutral while turning. Is there any way to check the steering sensor and as for the scope. I don't have acees to one but I should try to get one because it will really help me with this. Great help everyone.

 

[DailyDrifter]

I talked to the guy at work today. He said your gonna have to have a scan tool on the car and record the data when it starts to act up. He was leaning towards a wheel speed sensor. But it could also be the steering pos. sensor.

 

[BlackMetal]

I remember one of these when I worked there, not sure what our conclusion was. It was a bigger vehicle either a Sequoia or a 4 Runner, same thing if you were making a tight turn at parking-lot speed the ABS would activate. I know tech support told us to check the sensor rings and also hook up a scan tool and check the yaw rate sensor. Sorry that I don't remember how we ended up fixing it.

 

[gunslinger]

Unfortunately if you find the yaw rate sensor (steering angle sensor) is bad, the VSC module will need to be re-initialized with a Toyota scan tool.

I would check the sensors first to see if there is rust built up under them. Otherwise you're probably looking at going to Toyota/Lexus. :frown:

 

[Sal Lubrano]

Thank you everyone for your help. Gunslinger I pulled all the sensors and cleaned them. Still have the problem. Looks like Lexus will win. They build these cars today so the average person can not work on them. I will post what the the problem is after I open the piggy bank for the dealer.

 

[DailyDrifter]

Take it to a toyota dealer, they probably have a lower shop rate