So my 04 LS430 auto rain sensor operates only in intermittent mode. It swipes twice when activated and then intermittent.
Lexus diagnosed it as follow

1. P-IG,AM1, D-J/B, ALT fuse (not sure what all that is)
2. Rain sensor circuit (they said okay)
3. Rain sensor (Installed NEW Lexus rain sensor with NEW Lexus Gel Pad recently)
4. Passenger side J/B ECU (its $866 plus two hours to install!)

I'm down to item 4 they said. There was some mention it might be the aftermarket FY windshield but highly unlikely.
I've reset the ECM by disconnecting the battery for 15 mins and to no avail. (if that's even how you do it)

The rain sensor when played with acts funny at times and will speed up and slow down. Removed from the windshield make no difference.
Actually I'm thinking its still the way its hooked up and possibly a bad wire at the rain sensor.

How many experienced LS430 owners agree with Lexus the passenger side junction box ECU needs replacing? Part # 82735

This is the last issue I have to fix.

Anyone?

 

I don't have any experience with this, but there are a few different threads as to where owners have replaced the windshield with aftermarket glass (non OEM) and have described the symptoms you are having.

 

Again I'm no expert, but when I got the car, I was surprised that if one touches the sensor from the back, the wipers sweep. Did touching the old sensor accomplish that, and touching the new one? Meaning, I don't know the logic on why, just the symptoms (this would not have any effect on my other car with rain sensing wipers).

Is there some way to test a brand new sensor to rule out the windshield, i.e. to do something to it, possibly removed from the windshield, to force the wipers to sweep. There has to be some logic statement where if x happens, then no rain sensor, intermittent only....just speaking out loud...

 

What I'm hoping is someone might have the actual troubleshooting procedures. I don't trust my Lexus dealership.
My own thoughts on this are;
- IF I was to disconnect the rain sensor from the window and the four pin jack, how would the system operate to narrow down the problem? Would it still swipe twice, (mine will still swipe twice and sometimes only once when selecting "AUTO" and still act like intermittent wipers instead of rain sensing.) Would someone elses not do anything at all? This might indicate the issue is not in the rain sensor.
- Does the 4th step above mean the problem is within the passenger side JB ECU and could be a fuse or even something else? I shouldn't have to replace the entire thing I would think, I'm not throwing any codes and no other system malfunctions are showing.
- And the dreaded windshield replacement haunts me like a bad cold. Others have said this had no effect on theirs. It could be and I'm trying to figure how I might get insurance to replace it. Plus the dealer Premaplated mine.
- Anybody replaced this Passenger side JB ECU? Wonder if a used one would work?

Should be a way to further test this I think.

Thanks

 

I had similar problems after my windshield was replaced with a non-oem one. We troubleshot everything to no avail before the insurance company agreed to replace the new windshield with an OEM one. Worked like a charm for me.

 

I have the same issue with my non-oem. Does anyone have the part number for the gel?

 

So how did you convince them to just simply replace it?

 

I called the safelite guy back and he came out with a new gel pad (OEM Lexus) and changed right away - no begging required!

 

when inspecting the car for sale I saw the windshield was cracked. Asked the PO to replace the windshield. He did. Windshield was not OEM, Automatic wipers do not work. Had no idea that it was related to non OEM

 

"Whoa" hold on there. I'm not sure I buy this whole non OEM window and the rain sensor won't work. I don't believe there's anything magical about a "Lexus" window vrs a non OEM replacement window. In my case a "FY" considered good enough to be a BMW OEM window. However, Genuine Auto Glass who does work for Lexus said its a possibility. It just seems so improbable. And how can you tell without first having to replace the windshield this would be a fix?

However with that, I'm willing to give it a shot once I truly rule out other possibilities.

I think my problem is intermittent. Playing with the NEW SENSOR and or a combination of starting and stopping "AUTO" IT STARTED WORKING PROPERLY. I cannot seem to duplicate and restore full function.- and It would only swipe when I sprayed water on it. When I turned off "AUTO" and back on, it went back to double swipe and intermittent operation.
So any thoughts on troubleshooting such as if I remove the rain senor off the window and turn on "AUTO" it will act strictly as intermittent with no initial swipe upon selecting "AUTO. With the sensor connected, it goes back to a double swipe when activating "Auto" and be intermittent. I understand this behavior indicates a malfunction? But WHAT? Relay? Bad wire? Windshield?

Anyone got the pin voltage readout for a 2004 LS430?

If I can just get this fixed to satisfy my OCD, I'll be set.

 

My son has a auto glass shop. He looked at the replaced windshield and said: dad the PO replaced the windshield with the cheapest on the market. Your rainsensor will not work with it.
Here it is - straight from the horse's mouth

 

addendum
He said the Lexus windshield is very different from other replacement windows. He has an ongoing struggle with the insurance company. They always push to replace the window with the lowest cost. The majority of Lexus owners would not even think about that. They find out that the sensor does not work and think it is an electrical problem. By the time they get to the dealer it is too late. The insurance company will not replace a "good" used windshield

 

addendum
He said the Lexus windshield is very different from other replacement windows. He has an ongoing struggle with the insurance company. They always push to replace the window with the lowest cost. The majority of Lexus owners would not even think about that. They find out that the sensor does not work and think it is an electrical problem. By the time they get to the dealer it is too late. The insurance company will not replace a "good" used windshield. Just check and see what a Lexus windshield cost and compare it with other windshields

 

Safelight was working with the bodyshop that was doing some other work on the same job (the rocks that cracked my windshield also chipped the front of the car and the hood). The bodyshop was the mediator between Safelight and USAA (my carrier) and they got authorization after they tried a new sensor assembly (fail) new gel pad (fail) and a full OBD code check (no odd codes). The windshield was the only other piece it could be, and it was.

 

I had this argument with the lizard co. when I was with them. Terrible, wasted 40 min. of both of our times, like it was a game to the phone rep. Got the original BMW OE glass with the BMW logo.

When I went to the hands people I got a real agent and told him about this experience. He stated it would not be the case with the hands people. But he has never been tested and I bet it's the same problem if I need new glass. The lizard co. spec'd out used and aftermarket parts, on a brand new (brand spanking new) BMW loaner that I had an accident in. Because saving costs, dropping risky people, raising premiums as the vehicles are 1/10 of their original values, is the name of the game in insurance, I really don't get the tv ads at all--are we that stupid?