Code P0500: Vehicle Speed Sensor Malfunction

What Does Code P0500 Mean?

Diagnostic trouble code (DTC) P0500 stands for “Vehicle Speed Sensor (VSS) Malfunction”.

This engine code shows up when the powertrain control module (PCM) or engine control module (ECM) finds inaccurate speed readings or no signals from the vehicle speed sensor (VSS). 

But what does VSS do?
The vehicle speed sensor monitors wheel rotations and sends a pulse signal to the combination meter, which calculates the vehicle speed. It’s located on the transmission output shaft, connected to a speedometer or odometer cable. In some vehicles, the VSS sends signals directly to the PCM/ECM.

NOTE: The number of pulse signals generated per rotation can vary depending on the make of the vehicle. 

This speed information powers other vehicle systems, including the transmission control module, cruise control, and speedometer. For example, the speed signal controls the automatic transmission, dims the interior lights, and locks the doors.

In many modern cars, the ABS wheel sensor takes over the job of the VSS. Both measure wheel speed, but the wheel speed sensor sits at the wheels, behind the rotor.

That’s why vehicles without a dedicated VSS can still trigger the DTC P0500 and turn on the check engine light. In this case, the ECM or PCM calculates speed from the signals sent by the wheel speed sensors.

Other definitions for the P0500 code are:

• Vehicle Speed Sensor “A” Range/Performance
• Vehicle Speed Sensor “A” Intermittent/Erratic/High
• Vehicle Speed Sensor “A” Low Input

What Are the Common Symptoms of DTC P0500?

A vehicle speed sensor malfunction may lead to inaccurate speed readings and cause symptoms like:

1. The check engine light turns on
2. A faulty speedometer or odometer
3. Cruise control malfunction
4. Erratic shifting as the transmission control module uses vehicle speed to determine when to shift 
5. The anti-braking system (ABS) warning light turns on  
6. The ABS module or traction control system may not engage properly
7. The car jerks when driving
8. Hesitation during acceleration
9. Loss of power
10. Decreased fuel efficiency

What Are the Causes of Code P0500?

Here’s what usually sets off this trouble code:

• Issues with the VSS wiring, connector, or the drive gear
• Broken reluctor ring or wheel (toothed sensor ring), as it can prevent the VSS sensor from generating a proper signal for the ECM 
• Low transmission fluid levels (for transmission-mounted VSS)
• PCM issues (PCM not programmed to match the vehicle’s actual tire size)

Can You Still Drive with Trouble Code P0500?

Technically, you can drive with a P0500 code, but it isn’t safe or recommended to drive with a vehicle speed sensor malfunction. 

Here’s why:
If the speedometer isn’t working, it’s impossible to know if you’re within speed limits, putting your safety and license at risk. Problems with the ABS module or traction control can also make driving dangerous in poor weather or slippery conditions.

In vehicles with automatic transmission, the issue can disrupt vehicle systems, like the transmission control module, causing problems like hard shifting.

To avoid such troubles, a vehicle owner should get a certified technician to resolve the P0500 fault code before driving again.

NOTE: Regular maintenance, such as faulty sensor checks, wiring inspections, and gear cleaning, can help prevent these issues before they turn serious.

How to Diagnose Fault Code P0500

If you don’t have the right tools or expertise, it’s best to consult a mechanic to diagnose this code. A misdiagnosis can lead to unnecessary repairs and leave the real issue unresolved. 

Let’s check out how a certified technician will troubleshoot the problem:

1. Your mechanic will use an OBD II scanner to scan for any other error code, like P0502 or P0720.

2. Then, they’ll visually inspect the vehicle speed sensor, wiring harness, and connector for damage.

3. They’ll use a scan tool to confirm if your vehicle speed sensor signal is present while driving. This step verifies whether the speed sensor data is accurate.

4. Your mechanic will check the VSS with a multimeter to see if the voltage runs through it. If they notice a dead or open vehicle speed sensor circuit, they’ll replace the faulty sensor.

5. For transmission-mounted VSS, they’ll examine the plastic or metal drive gear for wear or damage that could prevent the sensor from reading accurately.

6. They’ll also check for broken teeth, cracks, rust, or debris on the reluctor wheel that could distort the speed information sent to the ECM or PCM.

7. If the sensor and mechanical components are fine, they’ll test the PCM’s ability to receive and interpret the VSS signal.

8. After clearing all codes, they’ll start up your vehicle, reconnect the OBD II scanner, and check the speed sensor data.

9. Finally, they’ll test drive your vehicle to confirm whether the vehicle speed sensor fault reoccurs and triggers the P0500 code.

How to Repair P0500 and What Does it Cost

Depending on the cause and diagnosis of trouble code P0500, here are some ways your mechanic may fix the issue:

1. Replace the vehicle speed sensor or ABS speed sensor if it’s malfunctioning or damaged. 
2. Swap out the malfunctioning vehicle speed sensor drive gear (like the connector wire and VSS wiring harness)
3. Clean the rust and debris from the reluctor ring or replace it in case of damage.
4. Replace the PCM or fix damaged wires.

Here’s what you need to shell out for these repairs:

• Reluctor wheel replacement: $270+
• Wheel sensor replacement: $200 to $400
• Vehicle speed sensor replacement: $280 to $360
• Powertrain control module replacement: $700 to $2,000