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B268F BMW Fault Code

Check B268F OBD Fault Code Reason
Description:

The Transmission Fluid Pressure Switch allows the engine's control module (PCM) or Transmission Control Module (TCM) to use hydraulic fluid to engage the clutches in the transmission to allow for smoother shifting while driving. If the PCM or TCM detects an issue with the hydraulic clutch or the pressure switch, the BMW PCM or TCM will set code B268F

B268F Code Symptoms :

See B268F in engine

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. B268F 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 B268F

B268F 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 B268F code ?

See B268F repair manual
  • Exhaust tube
  • Faulty Air fuel ratio (A/F) Sensor 1 Bank 1
  • Faulty Crankshaft Position Sensor (POS)
  • Internal electrical failures in actuator motors/solenoids.

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.

BMW Cars that meet B268F error