1994 Toyota Corolla Transmission cut out

I have a 1994 Toyota Corolla wagon. For the last 6 months the transmission has periodically cut out while I am driving for 10 to 20 seconds. I took it to the Toyota dealer and he test drove it for almost an hour with no problems. It happens infrequently. Then recently it happened again and the speedometer also cut out and went to zero. I was able to shift into a lower gear and drive that way for a minute or so. Then the speedometer cut back in and I was able to shift into Drive and all was well. I took it back to the dealer who did another test drive and then dropped the transmission to check for gunk or build up in the trans oil filter. None was found. He reinstalled the trans pan with a new gasket and topped off the fluid. He then did another test drive and all was still normal. The mechanic is stymied and can’t think of anything that it can be. Any suggestions?

It is very possible that you just need to have the Vehicle Speed Sensor (VSS) replaced. On some vehicles this is a very easy job, on others it is a bit more involved, but the combination of symptoms leads me to suspect the VSS.

Thank you … I will check with the mechanic. He did tell me there is no computer control module on this vehicle because it is too old. Would there still be a VSS?