B1261 BMW Fault Code
Check B1261 OBD Fault Code ReasonFuel Rail Pressure Sensor in Range But Low The comprehensive component monitor (CCM) monitors the FRP pressure for acceptable fuel pressure. The test fails when the fuel pressure falls below a calibrated value.
Low fuel pressure Damaged BMW FRP sensor Excessive resistance in circuit Low or no fuel A FRP PID value below 551 kpa (80 psi) indicates a failure Low or no fuel A FRP PID value greater than 896 kpa (130 psi) indicates a failure.
B1261 Code Symptoms :
The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. B1261 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 B1261
B1261 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 B1261 code ?
- 1Camshaft Position Sensor circuit poor electrical connection
- Camshaft Position Sensor harness is open or shorted
- Faulty Camshaft Position Sensor
- Open or short in the VCT circuit
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.
