Strange Abs Noise And Shudder When Coming To Complete Stop

[jaycee]

I've read in the forum about transmission shift problems between certain gears with these cars but don't know if my symptom applies. 2004, AWD with 35k miles, however mostly short stop and go driving. Did a drain/refill of the tranny fluid and it didn't change the below..


When applying the brakes to come to a complete stop, there's kind of a abrupt downshift that I can even feel in the brake pedal. The car even has a last second little shake/shudder and a bit of a clunk..

Difficult to describe, so here's a short YouTube video as well. (you may have to turn up the vol to hear it)

Edit : Definitely NOT tjhe transmission. Pulling the ABS fuse, the car brakes normally. Suspect the rear wheel ABS speed sensors which are virtually impossible to remove without breaking. Fronts were easy and filthy.

Lexus 2004 RX330 transmission downshift when stopping - YouTube

[RX400h]

That appears to be what many other RX330 owners have complained about. There was an upgrade/TSB available for early versions of the ECT software. You may want to check to see if this was done by your dealership. From what I have read, it worked for some vehicles, but not all.

[jaycee]

Thanks for the reponse Dave. I've read a lot re transmission shifting problems when accelerating and the applicable TSB's both here and on the "other" forum.

However, they don't appear to apply to our car. All forward gears shift jusrt fine. It's just as the car does it's final downshift as it comes to a complete stop and as I mentioned, it can be felt in the brake pedal as well. I know it's not the brakes because it doesn't do it if I shift into neutral first.

[RX400h]

Frank,

Have you asked a service manager if this is something he or she has experienced with other customers' vehicles. I know they like to say " Bring it in and we'll take a look/listen." but sometimes a manager will give out that information.

In the absence of that, let's hope someone or two will chime in with personal experience.

Dave

[jaycee]

Not yet...I wanted to see if anyone else on the forum has experienced this. But, certainly my next step as I don't want to damage the tranny.

[jaycee]

Dave, First let me correct something in the op. The symtom(s) are in fact there when stopping the car with the gearshift in neutral.

I took it to the dealership today and spoke with the service manager. Firstly he said he has never heard of this type of problem before and couldn't surmise what's causing it. A "professional" would have to look at it. I asked him to take a quick test drive around the parking lot and he said no, that wouldn't help. I suggested that he would be able to help future customers if he experienced first hand what was going on. He then agreed to drive it. Afterwards he commented that it felt like the anti-lock brakes were kicking in.

Of course the next step was to have it diagnosed @ $136.00, which I politely passed on.

I'll have a look at the service manual and see if I can pull the fuse, or something else, to disconnect the anti-lock feature temporarily.

I fthe symotom dissapears then there's the problem. Now that I know it does it in neutral, I'm inclined to think that's the culprit.

Lastly, I was talking with my neighbor earlier, who has a 2000 RX300 AWD, and, lo and behold, they have exactly the same problem.

[RX400h]

I sometimes hear a slight thunk when I brake from a low speed, (backing out of the garage) but I'll bet it's just one the calipers that needs grease on the slides. Non-hybrid vehicles generally have their caliper slides greased when pads are replaced, but hybrids typically don't need pads for more then 100,000 miles, so general caliper maintenance tends to get bypassed.

But that's amazing that the service manager "never heard of this type of problem". What should happen among the service employees is communication among them and the mechanics, regarding any issues.

Many years ago when my wife had an 86 Honda Accord, the turn signals stopped working. I called the local dealership's service manager and asked him if he'd experienced this issue, before. He told me that not only was it very common, but also that there was a simple fix - push and pull the emergency flasher button, multiple times. Apparently, power to the turn signals was routed through the emergency flasher switch. That switch's electrical contacts gradually corroded to a point where power would not pass through. It made sense because we never used the emergency flashers.

So that service manager saved me a trip and the cost for a mechanic to cycle the flasher switch.

[jaycee]

Dave, in general your experience in the past was the same thing that I found. Today, things appear to be quite different. The service manager is more of a "manager" than a knowledeable overseer. It's all about writing the business. You'd think that they would diagnose and expect that you're going to give them the business. Instead the goal is to get that $136.00. No fishing expeditions for me. I also noticed that all the service advisors are new since I was at this dealership a year ago. (I tend to go to my local Toyota dealer who is only 3 miles away, while Lexus is 15 miles)

Edit : This may be the answer in this thread : http://www.clublexus.com/forums/rx-second-generation/702117-abs-problem.html