Symptoms
Potential
This code differs from the P2158 code in that it may not trigger the Malfunction Indicator Light (MIL). The potential symptoms are basically the same as the VSS P0500 code:
- Loss of anti-lock braking
- The “anti-lock” or “braking” warning lights on the dashboard may be illuminated
- The speedometer or odometer may not work correctly (or at all)
- Your vehicle’s RPM limiter may be reduced
- Shifting of an automatic transmission may become irregular
- Other symptoms may also be present
Causes
A P2159 DTC fault code can be caused by one or more of the following:
- The vehicle speed sensor (VSS) “B” is not reading (functioning) correctly
- A broken/frayed wire leading to the vehicle speed sensor
- The vehicle’s PCM is not properly configured for the vehicle’s actual tire size
Diagnostic and Repair Steps
A good first step for a vehicle owner or DIYer is to search for Technical Service Bulletins (TSBs) for your specific vehicle make/model/engine/year. If there is a known TSB (as is the case for some Toyota vehicles), following the instructions from a bulletin can help save time and money in diagnosing and repairing your issue.
Next, visually inspect all wiring and connectors leading to the speed sensor. Carefully look for chafing, exposed wires, broken wires, melted areas, or other damage. Repair as needed. The sensor’s location depends on your vehicle. The sensor could be on the rear axle, transmission, or possibly the wheel hub assembly (brake).
If the wiring and connectors are in good condition, check the voltage at the speed sensor. Again, the exact procedure will depend on your vehicle’s make and model.
If everything appears correct, replace the sensor.