B3879 BMW Fault Code

Description:

Throttle Position (TP) Sensor Intermittent The TP sensor circuit is monitored by the PCM for sudden BMW TP rotation angle (or voltage) input change through the comprehensive component monitor (CCM). If during the last 80 warm-up cycles in key ON engine running the BMW PCM detects a TP rotation angle (or voltage) changes beyond the minimum or maximum calibrated limit, a continuous diagnostic trouble code (DTC) is stored. Poor continuity through the TP sensor connectors Poor continuity through the TP harness Intermittent open or short inside the TP sensor While accessing the TP V PID on the scan tool, lightly tap on the TP sensor or wiggle the TP sensor connector and harness.

B3879 Code Symptoms :

When you turn on the ignition, the Service Engine Soon or Check Engine B3879 light should flash briefly, indicating that the OBD system is ready to scan your vehicle for any malfunctions. After this brief flash, the light should stay off while you drive as long as no problems are detected. If so, you'll be glad to know that your vehicle is equipped with an early warning system that could save you time, money, and fuel in addition to helping protect the B3879!

Diagnosis And Repairing B3879

B3879 OBD2 specifically refers to the camshaft (cam) timing. In this case, if the cam timing is over-retarded, the engine light will be illluminated and the code will be set.

How to fix B3879 code ?

• Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
• Exhaust gas leaks
• Incorrect Positive Crankcase Ventilation (PCV) hose connection

One example of this would be when an bmw automatic car in placed in gear. To prevent the added drag from the torque converter and transmission from reducing the idling speed, the PCM will command the idle control valve to allow more air to enter the engine, while at the same time, adjusting the injector pulse width to inject more fuel to suit the increased amount of air. Note that the idle air control valve is closed by the PCM when the throttle plate is opened to prevent excess air from entering the engine.