The vehicle speed sensor (VSS) is a sensor that measures the speed of the vehicle. The VSS is used by the engine control unit (ECU) to calculate the engine speed, transmission shift points, and fuel injection.
If the VSS fails, the ECU will not be able to accurately calculate the engine speed, transmission shift points, or fuel injection. This can cause a number of problems, including:
* The engine may stall or run rough.
* The transmission may shift erratically.
* The fuel economy may decrease.
To troubleshoot the B123 code, you will need to:
1. Check the VSS connector for damage.
2. Check the VSS wiring for damage.
3. Replace the VSS if necessary.
Here are some additional tips for troubleshooting the B123 code:
* If you have access to a scan tool, you can use it to monitor the VSS signal. The VSS signal should be a steady voltage that increases as the vehicle speed increases.
* If the VSS signal is not steady, or if it does not increase as the vehicle speed increases, the VSS is likely faulty.
* You can also try to clean the VSS. To do this, you will need to remove the VSS from the vehicle and clean it with a mild detergent and water.
