Speedometer Issue

[pittsbfan2000]

91 LS 400 150k miles.

Just started having an issue with my speedometer, when i leave for work in the morning the needle on my speedometer will not move. After about 7 or 8 miles going down the road around 70mph the needle will gradually start to move up towards 70, after about another 4 miles the needle seems to work fine after that. The rest of the day things are fine. While i was going 70 i did turn the cruise control on and it worked fine. But the speedometer still stayed on 0.

Any ideas on where to look?

[jbsmithsa]

91 LS 400 150k miles.

Just started having an issue with my speedometer, when i leave for work in the morning the needle on my speedometer will not move. After about 7 or 8 miles going down the road around 70mph the needle will gradually start to move up towards 70, after about another 4 miles the needle seems to work fine after that. The rest of the day things are fine. While i was going 70 i did turn the cruise control on and it worked fine. But the speedometer still stayed on 0.

Any ideas on where to look?

I'm having the same issue. I have found that I can bump the dash above the instrument cluster and it will jump into place and start working.

[93ls400walt]

There are many post on this issue. You will find all you care to know by doing a forum search with keywords.

[harjp]

There are many post on this issue. You will find all you care to know by doing a forum search with keywords.

There are, as a search reveals, in fact only a few posts on this issue. And none of them resolve the problem.

The only thing you can find out from reading these posts is (1) a number of LS owners experience their speedo and/or tach going out, (2) some are able to restore functionality by banging on the IP, (3) for some, the odometer fails in combination with the speedo (which appears to make it a speed sensor problem and not a guage problem), (4) a part supplier in CA sells used tach and speedo guages which fix the problem, and (5) you can re-solder the connections at the back of the speedo and/or tach and this will fix the problem.

Here the "fix it" post:

The problem is the solder eyes on power supply boards on the back of the dash console. remove the dash change all the small silver caps on both ckt. boards and resolder as many of the eyes as you can this will solve your problem.

Unfortunately, this was the posters fifth and last post, and he hasn't been heard from since. And no other member has verified or amplified on this advice.

I had the intermittantly working speedo for several months a couple of years ago. Since then, it has died completely. My tach, odo and trip meters work fine. Two dealers have generously offered to fix the speedo problem for a mere $1000 or about 1/5 of my car's book value.

I'm fine without the speedo, really, but my girlfriend and son aren't. Which is kind of OK since it discourages them from driving my car, but sometimes they need to.

I would love to try fixing the speedo if someone could walk me through removing the dash and instrument cluster. Another option is to send the cluster off to lexustech.com --- who WILL show me how to remove and re-install the cluster. My last option is to buy a GPS device which will cost less than $1K and give me speedo, direction, elevation, maps, and all the other features of a good GPS.

Nonetheless, I'd really like to get the speed working again.

[SKperformance]

Cluster removal

http://www.lexls.com/tutorials/electrical/...entcluster.html

[CUMan]

I have also had the problem of the non-operative tachometer and speedometer needles on my 93 LS for about two years. The problem occurs primarily during the warmer months of the year. I can usually get the tachometer to work by rapping on the dash directly over the tach. The speedometer usually jumps to its proper reading after driving for a while. Both needles usually work fine for the rest of the day. The next day they again refuse to move when I crank the car.

To my knowledge, there is no one who has a guaranteed fix for this problem. Jim Walker does a lot of work on Lexus instrument clusters, primarily involving the non-illumination of the display during cold weather. When I last communicated with him, he had not yet come up with a fix for the needle problems.

Another Lexus instrument repair service, MrWhizard, also does not yet have a fix for the needle problem.

[harjp]

Cluster removal

http://www.lexls.com/tutorials/electrical/...entcluster.html

Thanks!

[93ls400walt]

I did not state that you would find the fix for this problem. Only that you would find this to be a somewhat common. And frustrating problem.

[harjp]

And frustrating problem.

Agreed!

[harjp]

By the way, I spoke to a local tach and speedo repair guy today about the LS400 problems. He claimed to be very familiar with the problem.

He told me the only reliable way to do a fix was to change out the pc board that is failiing. And Lexus charges about $600 for those boards! Not only that, this guy says that down the road, sooner or later, the NEW BOARD will fail just like the old one!

Basically, he told me not to bother spending my money. That if I wanted to sell the car and make the speedo run, I should get a used board from a junked car, which will work for a little while. And I tend to believe anyone who gives me advice that runs counter to their finanical interest.

Now am I way off base here, or is the cost to manufacturer those boards fairly cheap? Who do I talk to at Lexus to "demand" that they start giving these boards away for what it costs to make them, which is the least they could do for making faulty boards in the first place.