My 1994 Toyota Corolla’s speedometer just stopped working while I was driving this morning. Does this mean that there could be something worse going on than just my speedometer?
This could be something as simple as a Vehicle Speed Sensor (VSS) that needs to be replaced.
Does the car display any other symptoms, such strange shifting behavior for the transmission?
Your vehicle uses a speedometer cable. The speedometer cable is probably broken.
My research indicates that this year Corolla uses a Vehicle Speed Sensor to send a stream of pulses to the ECM or the speedometer head to display the vehicle speed. My experience on an earilier (~1990) model Corolla was that the VSS sent the pulse signel to the speedometer head where the signel was amplified, cleaned up, and drove a stepping motor which actually ran the speedometer as if a cable were attached.
Since the motor also drove the trip odometer and accumulating odometer, if either of these jammed that would stop the motor. So try resetting the trip odometer a couple of times. You might get lucky and have the trip counter jammed or the reset mechanism still engaged. If not you might need to replace the speedo head. Check with a speedometer shop to see if they can help.
Since the signel from the electronics in the speedometer head sends a signel to the ECM, if you do not have a Check Engine Light, the VSS may be okey. If you do have a CEL, check for codes and see if you have a VSS related DTC. If so you might just go ahead and replace the VSS in the transmission.
If you look at the top of the transaxle, you’ll see the VSS. Connected to the top of the VSS is the speedometer cable.