P0402 BMW Fault Code
Check P0402 OBD Fault Code ReasonVariable Cam Timing Over-advanced (Bank 1) The comprehensive component monitor (CCM) monitors the VCT position for an over-advanced camshaft timing.
The test fails when the camshaft timing exceeds a maximum calibrated value or remains in an advanced position.
BMW cam timing improperly set No oil flow to the VCT piston chamber Low oil pressure VCT solenoid valve stuck closed Camshaft advance mechanism binding (VCT unit) P0402 DTC is a check of the VCT unit.
P0402 Code Symptoms :
The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. P0402 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 P0402
P0402 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 P0402 code ?
- Erratic camshaft position due to low oil pressure
- Faulty TCM or TCM programming
- Faulty front heated oxygen sensor
- Oil flow restriction in the oil passages or the VCT valve body
At this point we are assuming that the fuses and relays are good. You will need to locate the PCM/TCM and the power input signal circuit using your vehicle information source.
Unplug the connector from the PCM/TCM, place the ignition switch in the ON position, and probe the appropriate circuit with the positive test lead of the DVOM.
