ACKerr

I've had this LS400 for over 20 years. It still runs very well, but is starting to show signs of aging.

The most recent one was yesterday. We drove about 150 miles to spend a few days with the grandkids. As we left home, the range indicated about 160 miles, so I figured we would make it without filling up. When we arrived, the range still said it had about 40 miles to go. After a day, the range said 25 miles. We had to take the kids about 8 miles to school the next morning. I figured I'd drop them off and then fill up. But when I started the car this morning the range said 0 miles. The fuel gauge was still just above empty. I can usually drive until it goes just past empty. But not wanting to run out of gas on the freeway, I stopped to get gas.

After returnng from dropping off the kids, I went to check the range, but could not get it to display. Now all that will display is a Low Washer Fluid warning that has been on for several years.

Can anyone suggest why none of the buttons on the side of the steering wheel (Mode, Function, or Reset) are working?

Thanks

400fanboy

I've had sporadic issues with low washer fluid warning erroneously engaging if I hit a big (and I mean big) bump, or drive over washboard gravel.

It's not problematic at the moment so I can't test this, but I'm reasonably sure the warning message is all that would display. It would override all of the other information, like you say, the miles till empty, fuel economy, etc on the trip computer display. And it would behave exactly as your system does now, only displaying the warning message with the associated red light.

Whether this is intended behavior is beyond me - but that's my experience on the matter. It's interesting that your warning has been on for several years but you've been able to ignore it and cycle through other modes until now.

ACKerr

I think my problem is different. That low washer fluid indictor has been on for years. During all that time until now, all of the other indicators worked perfectly.

The guy at the garage said it is a faulty sensor -- the washer fluid tub is full.

Yamae

I think you have two separate issues.

The low washer fluid warning issue is one of rather common problems as is discussed here and there.

The no display issue may be caused by the failing cluster meter unit. Probably the multi information display's portion is dead but sometimes it's caused by the clock spring built in the steering wheel assembly though. The troubleshooting requires measuring tools and skills. It's probably not for every DIYer though.

400fanboy

I may not have explained properly.

When that washer fluid warning shows up in my car, I lose the ability to control the cluster unit in exactly the same manner as ACKerr's. It will only display the washer fluid warning and the selecter buttons on the wheel do nothing. To my knowledge\memory, I have never been able to view any information when any warning message is displayed, windshield washer fluid and VSC errors are the two I've experienced this with. (I am reasonably confident of this because I was very OCD annoyed not being able to view the fuel economy and range till empty information).

The main difference is this:

For you, the warning has been on for years but until now, has never stopped you from controlling the dashboard display. I'm going to guess when you start the car, the error shows up, but you just press the middle button and cycle the screens to get the one you want?

For me, a warning message has always restricted my ability to control the display.

I bring up this story originally because you may be able to regain normal functionality simply by addressing the windshield washer sensor. If that warning is cleared, your car may be similar to mine where you regain control of the display once the warning has gone away.

Caveat: I may be wrong, and it doesn't address why the car randomly decided to act like this today for you and why it was different in behavior to mine in the first place.

ACKerr

Many thanks for those 2 links. 👍👍 When I get back home, I'll see if I can do any of those repairs.

ACKerr

I think you explained well. It's just that my symptoms seemed different to me. But maybe they are more similar that I thought. I'll see if I can do any of the repairs suggested by Yamae.

ACKerr

The plot thickens. As I was driving out this morning, the sun was right in my eyes. With the bugs on the windshield, I was having difficulty seeing. I turned on the windshield washer a few times. I didn't notice if it happened right away, but a little later I noticed that the range was displayed. I wonder if using the washer fluid changed something and got everything working again. I then filled up with gas and now everything is working. Maybe the car was just too hungry! (Thirsty?)

Losiracer2

do yourself a favor and unplug the low washer fluid sensor, it is pointless and not worth the cost of replacing.

ACKerr

That sounds like a plan. Is it something I can easily see under the hood? Will disconnecting it suppress the message and any interference it might be causing with the other messages?

My system keeps changing. Today I could see the low washer fluid message and the current MPG. Weird.

Losiracer2

The plug for the plunger sensor is just behind the driver side inner fender liner, you might be able to reach your arm inside like I was after removing a 10mm bolt holding the lower portion. Just peel that back slightly (don't have to remove the entire liner) and you'll be able to see the plug going to the sensor.