P15BF BMW Fault Code

Description:

Vehicle Speed Sensor (VSS) Intermittent Indicates the powertrain control module (PCM) detected an error in the vehicle speed information. Vehicle speed data is received from either the vehicle speed sensor (VSS), transfer case speed sensor (TCSS), anti-lock brake system (ABS) control module, generic electronic module (GEM), or central timer module (CTM). This DTC is set the same way as P15BF. However, it is intended to flash the transmission control indicator lamp (TCIL) for first time VSS circuit error/malfunctions. Refer to possible causes for P15BF

P15BF Code Symptoms :

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. P15BF code had an elaborate diagnostics procedure, including showing engine trouble codes on the air conditionning display. However, the system was troublesome, misunderstood by customers, and a rash of unpredictable failures led to the technology being quickly retired.

Diagnosis And Repairing P15BF

P15BF OBD2 reports a sensor fault, replacement of the sensor is unlikely to resolve the underlying problem. The fault is most likely to be caused by the systems that the sensor is monitoring, but might even be caused by the wiring to the sensor itself.

How to fix P15BF code ?

• Clogged or faulty fuel injector (s)
• Faulty TCM or TCM programming
• Camshaft Position Sensor harness is open or shorted
• Faulty Air Flow Meter

As long as the throttle plate remains closed, the idling speed and quality is controlled by the PCM via the idle control valve, and as can be seen from the above it should be clear that idle control on a gasoline engine is a complex affair.

For instance, if the engine is started in sub-zero temperatures, the PCM will command the idling control valve to allow less air to enter the engine to enrich the air/fuel mixture to create a condition which is roughly analogous to how chokes worked on carburetted engines to control idling in cold weather.