P2159 Vehicle Speed Sensor B Range/Performance

Description and meaning of DTC p2159

Basically a P2159 trouble code means that the vehicle's speed as read by the VehicleSpeed Sensor (VSS) B is outside of the expected range (too high or low for example). The VSS input is used by the vehicle's main computer called a PCM/ECM powertrain/engine control module along with other inputs for proper operation of the vehicle systems. How The VSS Works Typically, the VSS is an electromagnetic sensor that uses a rotating reluctor ring to complete an input circuit to the PCM. The VSS is mounted in the transmission housing at such a position as to allow the reluctor ring to pass by it in close proximity. The reluctor ring is attached to the output shaft of the transmission so that it spins along with it. As the reluctor ring passes by the electromagnetic tip of the VSS, notches and grooves serve to complete and interrupt the circuit rapidly. These circuit manipulations are recognized by the PCM as transmission output speed or vehicle speed.

p2159 diagnostic trouble code symptoms

This code is different from the P2158 code in the factthat it may not trigger the malfunction indicator light (MIL). Potential symptomsare basically the same as the P0500 VSS code:loss of anti-lock brakesthe anti-lock or brake warning lamps on the dashmay be litthe speedometer or odometer may not work properly (or at all)your vehicle's RPM limiter may be decreasedthe shifting of an automatic transmission may become erraticother symptoms may also be present

DTC p2159 - possible causes

A P2159 DTC trouble code may be caused by one or more of the following:The Vehicle Speed Sensor (VSS) B is not reading (functioning) properlyThere is a broken/frayed wire leading to the vehicle speed sensorThe vehicle's PCM is not correctly configured for the actual tire size onthe vehicle

How to fix OBD-II diagnostic trouble code p2159

A good first step to do as a vehicle owner or DIYer is to search for technical service bulletins (TSBs) for your particular vehicle make/model/engine/year. If a known TSB exists (as is the case for some Toyota vehicles), following the instructions in a bulletin can help you save time and money in diagnosing and repairing your issue. Next, visually inspect all wiring and connectors that lead to the speed sensor. Look closely for any chafing, bare wires, broken wires, melted, or otherwise damaged areas. Repair as required. The locationof 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 will depend on your make and model of vehicle. If everything looks OK, replace the sensor.

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