jaredmac11

97 Lexus ES300, 3.0L engine

Early winter last year, my speedometer and odometer started to not work properly. At first it was just blips where the odometer would blank out and the speedometer would drop to 0 while in motion.

Took it to a shop and they replaced the speed sensor, as the CEL indicated. A day later, same issue occured. Took the car back, they took out the speed sensor, put in the old one, and poked around with the wiring. Couldnt find issue. They believe the issue was either wiring, or possibly a bad cluster. Maybe a cold solder or something in the cluster.

I dealt with it for a few months since the issue was very intermittent. Then suddenly for another few months, the issue seemed to no longer occur... until last week. Speedometer/odometer is completely dead. In addition, last week I had difficulty shifting out of first gear. It just sat in first til I let off the gas a few times and it shifted. Hasnt happened since.

Spoke with a mechanic friend and he volunteered that it could be the ECU as well, he has replaced several ECUs in these cars.

Has anyone ran in to this? This car is not pretty anymore-- the paint is failing on the hood and trunk and roof. Its just not worth more than $1500. Therefore I dont want to spend $300+ diagnosing electrical issues. Found an ECU for $50 on Ebay.. I know its a gamble but I'm hoping that others have seen this to be a common issue and there's at least a decent chance its the ECU.

PFB

Make sure that all your fuses make good contact and are good. Also try disconnecting the Battery for 10 minutes or so. If you have a code reader than first retrieve any codes stored in memory.

It doesn't hurt to try and costs you nothing.

jaredmac11

Gosh, I havent even thought to check fuses. I'll give that a look tonight. 'Resetting' the ECU by unplugging the battery seems like a good idea too.. just in case....

jaredmac11

Bump,

Has anyone ran in to this? Ive read that a swapped speedometer could fix the issue, its just salvage yards have vehicles of unknown mileage and I fear I'd destroy my car's resale value (what little there already is). Hoping I can fix the issue, not replace it!

WILLYumD

I had a similar issue and I replaced my speedo/odo unit for $12.50 at my local LKQ Pick and Pull.
1. Get replacement speedo.
2. Desolder odo chip from old and new speedos.
3. Reprogram if necessary aka if your current odo is nonfunctional (check out speedkar99's tutorial).
4. Resolder, reassemble and smile.

Disassembly of the instrument cluster is relatively simple but can be a little frustrating with the limited space behind the cluster to unplug it. Overall, the hardest part of the process was desoldering and getting the programmer to work.

I'm just a kid in college. If I can do it, anyone can. Just take your time.

Once you reassemble your cluster everything will look the same, no one will be able to tell unless they open up the cluster again to look at the slightly different than factory solder pads.

jaredmac11

Perfect!! There is a salvage yard with a 97 Lexus ES speedometer, but they want $75. That was a bit pricey. Maybe it was cluster only, because I was hearing others getting speedometers for around $20. I figured it was a broken resistor/capacitor, but if its likely the failed chip, swapping those out cant be too impossible.

I did pull the cluster out. Its not awful. When I looked at the wiring and everything it LOOKED fine, but I certainly am not an electrician and dont have the eye for that. I will review the guide and look in to this

WILLYumD

Sometimes things just go bad with age, especially considering your vehicle is almost 20.
Mine's 18 and the tachometer is sticky, the radio LCD died years ago, but alas the show goes on.

When I went to my LKQ, I disassembled the cluster there (yes, I know, douche move) and took just the speedo. You could try that if it reduces the price, bring a Phillips head and maybe a small Phillips head if you have one.

TaninAuto

Hi, Tanin Auto Electronix here. We are vendors on the site. We repair instrument clusters and can definitely say that after 20 years, a cluster is going to need some TLC. Some are not repairable and if that is the case, we help locate replacements and program the correct mileage into them for you. If you replace the cluster and just want the correct miles, here is a link to our service:

http://www.taninautoelectronix.com/S...do_correct.htm

Let us know if anyone has any questions on the service or cluster issues.

Thanks!

jaredmac11

Could I just swap the clusters? Out of curiousity. Im not 100% sure it is the cluster, but for a $50 cluster I figured I'd try. Anyways, I took out the cluster, plugged it in, reset the computer and while the CEL went away, the speedo/odo still didnt work. Does the ECU expect to work with MY specific cluster? Or would the replacement cluster work? I didnt buy the cluster just in case that wasnt the issue.

WILLYumD

You can just swap out the clusters but the problem will be an incorrect odometer reading. The process I outlined is the fix for that.

jaredmac11

Understood. I was a bit surprised to see swapping the clusters did not fix the issue, so it makes me wonder if I was missing a step.

WILLYumD

When I swapped my cluster, I was confused likewise. Then I saw speedkar99's posts and realized Toyota put the odometer on a relatively easy to access chip (good and bad lol).

jaredmac11

So glad the other 2 clusters I found at the yard didnt work. I would have gone down a hell of a rabbit hole for nothing if I didnt test it first.

Luckily,
I Just found out there are TWO speed sensors. I believe the mechanic just replaced one. I am going to a parts yard to grab the 3-wire speed sensors. Allegedly these are low-fail parts, so I believe I can yank this one and be done with it.

If its not the 3-wire sensor, Im at a loss, honestly.

jaredmac11

I cant get to the bottom of this. Its not the cluster, swapped one at the auto yard. Its not the vehicle speed sensors. SWapped both of those out too. Im at a loss. I cant get my vehicle inspected like this so Im pretty much stuck. Any ideas?

WILLYumD

Are the wiring harnesses to the instrument cluster in order? Especially the third one (from left to right as plugged into the cluster). Could be a loose connection.
Maybe the screws connecting the speedo/odo to the board aren't in tight enough?