Hello Everyone, just got my 98 Sc400. So far the speedometer and odometer don’t work.
I’ve read on the forums about the VSS on the 97 and later SCs, but for the VVTI SCs, does the VSS Control the speedo and odometer or does it use ABS like the GS300/400 (with same transmissions and VVTI)?
anyone know? I already replaced the rearward VSS but it didn’t make any difference.
thanks

 

Update, I replaced the other VSS and it’s still not displaying. I also checked the ABS for codes and there were none. Yesterday when I had the car on I tapped near the cluster and the speedometer jumped a small amount. But still not doing anything.

anyone have advice on what’s wrong?

 

Check out this link...

https://www.taninautoelectronix.com/...luster-repair/

Is this what you have going on? I had it happen to my original cluster. I bought a used one because I wasn't aware the repair existed. Then the used cluster did the same thing. I used this service and paid for the odometer correction service as well to compensate for the mileage put on the replacement used cluster. I think it's been about 2 years, so far so good.

Hope this helps.

 

after the various attempts I’ve made, it seems like it. But I ask them what causes this. They said the speedometer doesn’t work because the motor goes bad. That’s fine. I understand. But they said the odometer goes because of certain small gears that go bad. which I don’t really think is the case. I just want to understand why the odometer stops reading. Then I’ll consider sending it. id like to exhaust all options before paying the 250 for the repair.

 

I'm not sure about the 98-00 VVT-i SC's specifically but I can say for certain that in the electrical schematics for the 92-94's, 95's and 96-97's the odometer circuit is fed by BOTH the 3-wire VSS sensor on the transmission and one or both of the front ABS sensors, making it a redundant system. Proof other than the electrical schematics themselves is that I was still getting an active odometer reading when I once had a temporarily disconnected VSS sensor at the transmission.

As for the speedometer not working (as well as the tachometer for that matter) those motors do tend to get stuck at 20++ years in some cars. LS400's have historically had the same issue. In that case Tanin Auto can often recondition the sticking RPM and Speedometer gauge motors and in some cases they may require full replacement (which they keep in stock at their facility).

For what it's worth I have the same occasional sticking tachometer and speedometer issue at current time and I need to send my cluster into them for repair. I have already checked my VSS wiring and sensor and those are fine so I know it is the gauges themselves sticking due to age and wear. The coolant temp gauge and fuel gauge are fine and those tend not to have issues (although a long while back in 2010 I did have to replace my fuel gauge with a new one from Lexus but that tends to be a very rare issue).

Slapping the top of the dashboard a bit cures the issue for as long as the car is driving but it tends to occur again randomly after I've shut it off and let it sit for a while. I would buy a cluster from them and send my original back as a core but 5-speed manual clusters are not usually something they keep in stock. That rarity may also be the case for 1998-2000 automatic clusters.

 

98+ has the A650e trans with two speed sensors, but they are two wire. And I replaced both, and it didn’t help. With the issue. I didn’t have any VSS codes anyway, but I figured it would t hurt. I need to check the abs sensors all around to make sure they arent loose or damaged. After that, I’ll probably have to send it in.

 

This video explains the 3 simultaneous symptoms others have had and shows the process of how it’s fixed. Hope this helps everyone who may run into this issue.
3 issues are:

1. 1. speedometer not moving

2. 2. odometer digital display is blank

3. 3. shifting is erratic while trying to accelerate