B0418 BMW Fault Code

Description:

Engine Coolant Temperature (ECT) Circuit High Input Indicates the sensor signal is greater than Self-Test maximum. The ECT sensor maximum is 4.6 volts or -50 C (-58 F). Note on some vehicles that are not equipped with an ECT sensor, CHT can be used and can set this DTC. Open circuit in harness Sensor signal short to power Damaged PCM Improper harness connection Damaged sensor ECT V PID reading greater than 4.6 volts with key ON and engine OFF or during any engine operating mode indicates a hard fault.

B0418 Code Symptoms :

OBD B0418 code and tailpipe testing are two different approaches to identify vehicles in need of repair. The OBD system looks for broken or malfunctioning emissions control components and B0418, while tailpipe tests sample a vehicle's exhaust to see if it is above or below certain prescribed limits. Given the robust nature of today's emissions control components, it is entirely possible for an individual component to malfunction without leading to an immediate increase in emissions at the tailpipe.

In such cases, other components (like the catalyst) can temporarily compensate for the part that is broken however, these other components can only do double duty for so long before they, too, begin to malfunction. In addition, OBD also monitors for and other malfunctions in the fuel system problems that traditional tailpipe tests were not designed to identify. Most state and local areas also include a gas cap pressure test as part of an emission inspection.

Diagnosis And Repairing B0418

B0418 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 B0418 code ?

• Camshaft advance mechanism binding (VCT unit)
• Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
• Intake air leaks
• Lack of fuel

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.