Can the car still be driven with a VSS malfunction?
4 Answers
Yes, the car can still be driven. A VSS malfunction is a sensor issue that causes abnormal speedometer readings. It is recommended to have it inspected and repaired at a 4S shop. Function of VSS: The Vehicle Speed Sensor (VSS) transmits the car's speed as an electrical signal to the Electronic Control Unit (ECU). This serves as a reference for controlling engine idle, automatic transmission shifting, torque converter lock-up, engine cooling fan operation, cruise control, and other functions. Types of VSS: Vehicle speed sensors can be categorized into three types: magnetic, Hall-effect, and optical. Typically, there is one speed sensor installed either in the drive axle housing or transmission housing. The VSS signal wire is usually shielded to eliminate electromagnetic and radio frequency interference from high-voltage ignition wires, mobile phones, or other electronic devices. This ensures uninterrupted electronic communication and prevents degraded driving performance or other issues.
The last time I encountered this situation was on the highway when the dashboard suddenly lit up with a warning light, and the speedometer dropped straight to zero. This kind of VSS fault is actually a broken vehicle speed sensor. To be honest, you can still keep driving, but it's a bit dangerous. The most obvious issue is that the speedometer stops working—you won't know how fast you're going, making it easy to get caught speeding or obstruct traffic. Additionally, many functions in modern cars rely on the speed signal, such as automatic transmission shift logic, which can become erratic. Cruise control won't work, and the ABS system might also fail. Although the engine can still run, I always recommend finding a repair shop as soon as possible. Driving without speed information is like driving blind.
After a VSS failure, the vehicle can still be driven mechanically, but the driving experience will be compromised. From my experience, losing the speed signal affects the shifting timing of automatic transmissions—often either delaying upshifts or causing sudden jerks. Additionally, functions like electronic parking and tire pressure monitoring may report errors. The most troublesome part is that the dashboard no longer displays the speed, so I usually rely on the speed prompts from my phone's navigation as a reference. However, it's important to note that driving like this for an extended period may damage the transmission control unit. I've seen cases where someone delayed repairs for a month and ended up paying over 4,000 for the fix.
With over a decade of auto repair experience, I frequently encounter this issue. When the VSS fails, the car can still operate, but it poses significant risks. The vehicle speed sensor doesn't just control the dashboard—it also regulates transmission shift points. Without its signal, the transmission defaults to a fixed shifting pattern. More critically, the ESP and traction control systems will deactivate, increasing the risk of skidding during wet-weather turns. My advice to owners who discover this fault: First, check for loose sensor connections. If the sensor is confirmed faulty, limit driving to short urban trips at most—avoid highways entirely. The safest option is to call for a tow truck.
