C3121 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.

C3121 Code Symptoms :

There are currently two main types of cylinder deactivation used today, depending on the type of engine. C3121 code for the pushrod design which uses solenoids to alter the oil pressure delivered to the lifters. In their collapsed state, the lifters are unable to elevate their companion pushrods under the valve rocker arms, resulting in valves that cannot be actuated and remain closed.

Diagnosis And Repairing C3121

C3121 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 C3121 code ?

• Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
• Exhaust gas leaks
• Camshaft Position Sensor harness is open or shorted
• EVAP canister or fuel tank leaks

Gear changes are accomplished by a command from the BMW TCM to energize the clutch actuator to release the clutch; after which various actuators inside the transmission disengage the current gear, and depending on current operating conditions, engage the next higher or lower gear ratio. All of this happens much faster than a human driver could change gears, and in most applications, gear changes are as smooth and seamless as on any fully automatic transmission.