Lexus Ls400 Speedometer And Tachometer

[Jarebear]

I just bought a 98 Lexus Ls400 and everything was working fine until one day the speedometer just stopped working, the needle would just stay at zero, and then the next morning while I was driving it started working again. Same thing with the tachometer as well. They both have been working on and off. All of the other gauges work. Does anyone have an idea what it might be? Also, a piece of plastic that is situated underneath the car right under the engine has gotten loose and drags on the ground. Whats the name of this part so I can get another one, or should I?

[steve2006]

The part you need is the Engine under cover No.1 part No. 51441‑50070 around $150.00 from Lexus.

As for the speedo and tacho needles a common fault on earlier models was excess lubricant on the shafts causing them to stick, try hitting the top of the dash next time it happens and see if they move.

Oh and welcome to the LOC.

[booztedgt]

Just joined the forum today, partially because of the title of this thread! I have a 2000 Lexus, experiencing the same issues. One, or both of the speedo/tach needles stops working, then will randomly come back to life. It stopped doing this for several months, but then did it again a few days ago. Took it to my local Lexus shop while the needles werent working, and they were able to determine that it wasn't the speed sensor on the transmission, so it's therefore likely an issue with the gauges themselves. If you look on ebay, or google search, you will find that there are a few companies out there that can repair the gauges. My local shop doesn't, but they referred me to an electronics shop here in the Atlanta area that can do the repair (and offers a lifetime warranty)...It was $300, including removal and reinstallation in the car. I don't really have anything to compare that quote to (since I'd have to remove and reinstall myself if I dealt with the ebay/internet companies). I'm on the fence about doing the repair, since it's been a problem so rarely. But if it gets worse or more frequent, I probably will do it as I'm trying to sell my car (only 18K original miles...shameless plug!)

[Minh in California]

I bought a used 2000 LS400 a couple of months ago. As soon as I drove off the used car lot, I noticed the problem with the speedometer and the tachometer. For me, sometimes they don't work when I just started the car. Most of the time, I drove for a few miles and they start to work again. I tried to see if I can detect a pattern but so far it appears to be random. Any suggestion will help. I just joined the club today.

[1990LS400]

It seems to be a common problem although I see more complaints about the speedometer than the tachometer. The speedometer needle in my 2000 LS400 started occasionally sticking a little over a year ago but only on warm days. The problem got worse as last summer progressed and I don't think it has stuck since last October. I've seen prices as low as $150 from a Florida company to fix the speedometer and as high as $850 from the Lexus dealer to remove and send the instrument cluster to a company in California for repair. My understanding is that the cheaper quotes involve repairing the circuit board in the instrument cluster and that the more expensive quotes involve replacing the circuit board. A local speedometer repair company said they could replace the circuit board for about $400 but they've never done it on a Lexus before.

I now regret that I didn't have the instrument cluster replaced with a brand new one in 2003 when the car was under its 4 year/50K warranty under a TSIB that addressed problems in the trip computer -- that might have bought me a few more trouble free years.

Whether or not I have the instrument cluster repaired depends on if I keep the car much longer - was planning to replace it this Spring but my wife wants me to continue driving it. And I still really like the car after all these years. At least I have other speedometers in the car - one on a Garmin GPS mounted on a bracket by the HVAC controls and another on the iBolt Dock n Drive application that automatically displays on my Android phone when it is in its charging cradle.

I'm reluctant to remove the instrument cluster myself and send it to a company I don't know for repair. I have the skills to remove/reinstall the cluster but I depend on the car and would not drive it without a cluster - particularly the fuel and temperature gauges. If we decide to keep the car, my current plan is to have the Lexus dealer take care of the cluster repair during the upcoming 180K service which is less than 5,000 miles away. Turnaround for the cluster repair is supposed to be less than one week and at least I'll have a decent ES or RX loaner to drive during that period.

[Minh in California]

I followed the suggestion by steve2006 to tap the dashboard when the needles were not moving and they came back to life instantly. Let say that the problem is really the excess lubricant in the shaft. Any suggestion on the remedy going forward? Since it only happen periodically, I probably will keep hitting the dashboard until they stop working completely. Thanks a lot for all your helps.

[1990LS400]

It has nothing to do with lubrication of the tachometer needle shaft. It is an instrument cluster ECU board problem.

I got an updated price from the local Lexus dealer two days ago for refurbishing the instrument cluster in my 2000 LS400: $1,025.30 including tax.

It will be easier for me to get fixed at a much lower cost after I buy another vehicle - which might be very soon ... wife and I are test driving a new vehicle tonight! I could then pop out the instrument cluster at my leisure and send it someplace cheap to fix.

[Minh in California]

In my case, they will come back to life instantly when I tap on the dash. With my understanding of physics, I don't see how this can be the problem of the ECU board. Did the Lexus dealer explain to you how they came to their conclusion? Thanks,

[1990LS400]

In my case, they will come back to life instantly when I tap on the dash. With my understanding of physics, I don't see how this can be the problem of the ECU board. Did the Lexus dealer explain to you how they came to their conclusion? Thanks,

Explain the laws of physics to which are referring and I'll run it by the PhD nuclear physicist who sits near me at work. I'd ask him today but this is a holiday for us.

You are far from the first person who has thought that the sticky tach and speedometer needles have to be caused by something mechanical. I wish it was. The tachometer and speedometer are not mechanically driven but are instead driven by electronics. While you currently can tap the dash to get your tach working, I can tell you that it usually gets worse and especially when outside temperatures spike. Have you ever wondered why the previous owner sold this car?

I got another quote today on refurbishing the instrument cluster - this one from the independent Lexus repair shop I've used since it opened in the late 1990's and owned by a man I met when he was a Lexus dealer service writer in the early 1990's. His quote was $750. He would also send the cluster to a California company. I didn't ask which one but it could well be the same company the Lexus dealer uses.

The $150 that the Florida company I mentioned charges is for fixing only the speedometer. There are additional charges for refurbishing additional gauges in the cluster. I don't know those people and am reluctant to send the cluster to them.

By all means do more research .... maybe contact some of the companies that repair these instrument cluster issues.

[Minh in California]

Thanks a lot for the feedback. Since this is a problem I can live with for a while, I will probably will take mine to a local shop specialized on Lexus next to see what they say. I will wait until the temp spike to see how it behaves. Thanks again for all your helps.

[LEXUS4MEtwo]

I picked up a nice 1993 400LS with 48,000 mile example but had some quick issues. They started with the intermittent tach/speedo issue.

After about 400 miles it went into limp mode. I was in Vermont so I took it to a local Toyota dealer in White River Junction, VT.

They decided I needed a new/rebuilt ECU. They gave me the part # of the ECU 89661-50042 which was in the car.

When the replacement came in, the Toyota dealership must have finally cross referenced the correct # ECU part 89661-50140. It was replaced and all seems to be good after 1,500 miles except the speedo and tach still intermittenly work.

My guess is that the ECU has nothing to do with the speedo/tach issue mentioned here. I'm still concerned that it might, but I'm begining to think it is the stuff you guys mentioned behind the dash. Your opinions please, the local service manager thought it eas more likely the stuff in the dash and not the main ECU being the culprit.

Thanks, Rich in Wisconsin

PS, I also picked up a nice 2004 430LS with 83,000 miles. So far, so good on that one.

[Gebo]

What is the name of the speedometer repair shop in Florida?

[1990LS400]

26 minutes ago, Gebo said:

What is the name of the speedometer repair shop in Florida?

Wow, I posted that over 6 years ago and sold my 2000 LS400 a few months later.  I'm surprised I saved the address of that Tampa, Florida company but I have no experience with them:  https://dnaspeedometers.com/

If I needed a Lexus instrument cluster repair today I would probably try Tanin first:  https://www.taninautoelectronix.com/product/1990-2000-lexus-ls400-instrument-cluster-repair/

[JJ ls400]

On 8/29/2011 at 1:15 PM, steve2006 said:

The part you need is the Engine under cover No.1 part No. 51441‑50070 around $150.00 from Lexus.

As for the speedo and tacho needles a common fault on earlier models was excess lubricant on the shafts causing them to stick, try hitting the top of the dash next time it happens and see if they move.

Oh and welcome to the LOC.

tap just a lil tap, i wouldn't recommend hitting it 

[Rod Shellshear]

Hi,

I have had a 1998 Lexus Ls400 now for 15 years.  I had the same problem with speedo and tacho working intermittently around five years ago.  The fault is not due to oil or grease or the cluster ECU.  When the cluster is removed and gauges separated from the circuit board you will see that both speedo and tacho gauges have four pins each which engage sockets on the ECU when the unit is assembled.  The sockets are individually pressed into the PC board and become loose over time causing a bad connection.  There is a simple repair which I did all those years ago with no further problems.

The solution is to remove each socket from the PC board and apply MG Carbon Conductive Assembly Paste (do a search to find a supplier) and refit each socket turned 180 degrees from its original position.  Apply a little paste to each pin of the speedo and tacho and reassemble.  I have heard the fuel and temperature gauges can also give the same problem so it is a good idea to do follow the same procedure for these at the same time.  

Trust this helps, Rod. (Australia)