Speedo problem - Toyota Nation Forum : Toyota Car and Truck Forums

DJR-TRD · 10-31-2010, 03:58 PM

Hi guys,
i have a problem with my 95. Speedo is way off. It reads way lower than I'm actually going. I compared with gps and when going 60mph it reads 35mph.
Can it be a faulty speed sensor (vss)? My odometer reads perfectly accurate, but my speedo doesn't. As far as I know the odometer and speedo both receive a signal from the vss, correct me if wrong.

Any suggestions?
Thanks!

speedy25 · 10-31-2010, 04:31 PM

Speedo is the problem. If the VSS was bad you would have other issues too.

-SP

gold94corolla · 11-06-2010, 01:06 PM

has it always been like this? Will it always read 25 mph under your speed? The needles come off and can be put back on in any orientation. I have adjusted my speedometer needles (multiple gauges) so that it matches my GPS.

DJR-TRD · 11-07-2010, 02:06 PM

It just reads way lower than it should. Let's say, at 40mph it reads 20mph. At 60mph it reads 35mph.

My car is carburated, so speed sensor is only attached to the gauges, don't think anything else.

Is there something I can do to test the sensor? Or if its the speed gauge, is there something I can also test?

Thanks

***Kiwi-Corolla*** · 11-07-2010, 06:17 PM

Typically if the speed sensor is faulty it would set off the CEL (code 42). I'd lean more towards the instrument cluster being at fault.

DJR-TRD · 11-12-2010, 05:10 PM

Hey guys,

just swapped my instrument cluster with a junkyard replacement. Still the same, so I'm leaning to a bad speed sensor.

Also on feb this year I remade the cluster's wiring harness due to a broken socket which made cluster lights go crazy.Everything works fine after the harness fix except for the speedo which is pretty innacurate. During the harnes fix I had to swap at least 2 wires which didn't match in positions due to cars being different years. Maybe I missed a wire and that could be my speedo problem; just want to make sure. On my speed sensor I have 3 wires (red/yellow, red/green, red/light-blue). My speedo has 4 pins, which read: IG+, E, 4P & S. I need to make sure they are linked to the right wires.

All I would need is a cluster wiring diagram to check that all wires are in the correct place. Does anyone know where I can find one. I've searched the web but nothing found. I would like to check on this first instead of maybe spending $40+ on a replacement sensor.

Thanks!!

DJR-TRD · 11-12-2010, 05:11 PM

Oh, since my Corolla is a '95 jap spec, it is carburated, so no ECU there.

***Kiwi-Corolla*** · 11-12-2010, 08:56 PM

Quote:

Originally Posted by DJR-TRD

All I would need is a cluster wiring diagram to check that all wires are in the correct place. Does anyone know where I can find one. I've searched the web but nothing found. I would like to check on this first instead of maybe spending $40+ on a replacement sensor.

Thanks!!

I'm not sure if this will be helpful to you, but here's a couple of instrument cluster wiring diagrams that I just scanned from some of my repair manuals. If you would like the full resolution images just send me a PM and I'll email them to you