C0518 BMW Fault Code

Description:

Variable 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) C0518 DTC is a check of the VCT unit.

C0518 Code Symptoms :

The C0518 Check Engine lamp is perhaps the most troubling of lights because it could mean so many different things, from you didn't screw the gas cap on tightly enough to look out for pistons flying through the hood and into the stratosphere. The easiest way to find out what this light is telling you is to hook your vehicle up to a scan tool. C0518 diagnostic tool looks a little like an oversized calculator and plugs into a communication port inside the car. After you instruct it to perform the scan, it speaks with your car's computers to find out exactly what's prompting the light to turn on.

Diagnosis And Repairing C0518

C0518 OBD2 may also be triggered by faults earlier down the line. For example, a dirty MAF sensor might be causing the car to overcompensate in its fuel-trim adjustments. As a result, oxygen sensors are likely to report fuel mixture problems.

How to fix C0518 code ?

• Erratic camshaft position due to low oil pressure
• Faulty Mass Air Flow (MAF) sensor
• Intake Valve Timing Control Solenoid Valve circuit poor electrical connection
• Variable Camshaft Timing (VCT) position circuit poor electrical connection

As the engine heats up and combustion becomes easier and more complete, the PCM will command the idling control valve to increase the amount of air entering the engine to suit the changing conditions.

However, when the load on the engine changes, say, when some electrical consumers or other systems are either turned on or off, the PCM adapts the signal voltage to the idle control valve to ensure that the idling speed remains stable, and at the RPM specified by the manufacturer.