Technical Definition:

Vehicle Speed Sensor A

Technical Description:

Possible Causes:

• The Vehicle Speed Sensor (VSS) is not reading (functioning) properly
• There is a broken/frayed wire leading to the vehicle speed sensor
• The vehicle’s PCM is not correctly configured for the actual tire size on the vehicle

Possible Symptoms:

• loss of anti-lock brakes
• the “anti-lock” or “brake” warning lamps on the dash may be lit
• the speedometer or odometer may not work properly (or at all)
• your vehicle’s RPM limiter may be decreased
• the shifting of an automatic transmission may become erratic
• other symptoms may also be present

Possible Solutions:

• The simplest thing to do is to reset the code and see if it comes back.
• Next, check all wiring and connectors that lead to the speed sensor. The location of the sensor depends on your vehicle. The sensor could be on the rear axle, transmission, or perhaps the wheel hub (brake) assembly.
• If the wiring and connectors are OK, then check the voltage at the speed sensor. Again, the exact procedure wil depend on your make and model of vehicle.
• If everything looks OK, replace the sensor.

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

Specific Makes: