Lexus SC430 :: Roof Stalling At The End Of Opening Or A Closing Operation

In an earlier thread, I talked about my roof stalling at the end of an opening or a closing operation. I just returned from a 260 mile round trip to the Lexus dealer to address this problem and get some other maintenance done..

To recap the problem, the roof appears to complete the opening or closing operation but won't finish it by turning off the red light on the switch. The switch then won't respond to either open or close. The roof stalls. It does this about 1 in every 10 or 12 open/close cycles.

Of course, if you drive the car with the red light still lit, you're treated to a chime when you go over about 5 MPH. Also, your trunk is locked.

I repeatedly re-try the switch of course, but without success. I eventually restart the car. Either the switch recovers or restarting does the trick, because so far I've been able to get the switch to work again. I would assume the stall will eventually stop being intermittent.

So, I talked with the Lexus service tech and he said he is very familiar with the SC roof. After hearing the symptoms, he quickly diagnosed a failing proximity switch. He was confident they could diagnose the problem.

So, I was due for the timing belt replacement and decided I'd have Lexus address both issues.

As I suspected, they need to catch the roof stalling to diagnose it. And guess what: They could not get the roof to stall. When the tech called to say my car was ready, I was disappointed my roof could not be fixed. The tech really did not know much about the proximity switches, like how many are in the roof. When I asked, he said replacing them all would be expensive and they did not believe one switch could be identified as the culprit from the description of symptoms.

So, here I am back 130 miles from the dealer with a tricky roof. I am thinking I will find out whether any local mechanic (Toyota or an independent) can find and fix the bad switch when it does fail.

Fortunately for the rest of you, the tech says this is not a common problem. I am aware of the manual operations to raise the roof, but really hope I don't have to go there!