Speed sensor on 1990 corvette

Corvette 1997-2005

Vehicle Speed Sensor

The VSS is located on the rear differential case.Here's a picture of a new sensor Sam.
Vehicle Transmission Speed Sensor at AutoZone com Best Vehicle...

The speed sensors will not fix it. This is something that these cars will do in hot weather. The instrument cluster need to be removed and the contacts from the printed circuit to the connector need to be cleaned. Over time they will lose contact and affect the fuel gauge or speedometer. You may have to replace the speedo cluster. Sometimes if you hit the dash just above the fuel gauge it will start working too. Been there done that, fixed mine as the printed circuit was coming apart at the harness connector.

The first thing you can always do is check your fuses. there might a blown fuse that need replacement.The 1990 Legacy has a mechanical speedometer . The speed sensor is a read switch in the speedometer head itself. So if your speedometer is functioning ( needle working properly ) then the internal read switch is defective. That requires replacing the entire speedometer OR it can be a defective connection between the speedometer and the ECU.If the speedometer is not working, then you can have a defective speedometer, cable, speedometer cable adapter ( on the tranny ) or internal speedo gear in the tranny. Thanks. you can rate this solution and show your appreciation.

first, check the vehicle speed sensor, located on the top of the transmission.

The speed sensor is located on the end of the speedometer cable at the transmission tailshaft

Code 34 has to do with your MAP sensor I believe from what I am reading. I don't know a lot about corvettes but it says MAP sensor voltage low. The C12 code I see is a normal code set dealing with no reference pulses being received by control module. In other words with the engine not running. It has to do with No RPM reference pulse.

speedometer sensor is bad....this will cost you about 115 dollars plus mechanic fee

Speed sensor is located on the top of the transmission on the passenger side.

A green flashing "S" is similar to a check engine light. It is telling you that something in or on your transmission is not functioning correctly, such as the speed sensor or shift control solenoids. If it starts flashing and the speedometer stops working or the transmission shifts weird, take it to a mechanic.