BMW May Have Tank Vent Defect
This bulletin applies to BMW vehicles produced up to March 2019 and with the following engine variants:
B36X, B38X, B46X, B58X, IB1 and XB1X.
Vehicles include 2, 3, 4, 5 and 7 Series.
The engine malfunction warning may be illuminated and one or more of the following faults are stored in the DME:
FC 191C02 (fuel tank ventilation system, 2nd discharge point malfunction)
FC 195014 (differential pressure sensor, tank vent valve, signal fixed)
FC 118001 (mixture control, mixture too lean)
FC 118401 (mixture control, mixture too lean, large deviation)
FC 124103 (mixture control, mixture too lean)
FC 124101 (mixture control, mixture lean, large deviation)
The cause may be a mechanical defect in the tank ventilation valve. The defect can also result in a very loud clicking noise when the valve is cycling. Refer to the accompanying photos for examples of good/bad valves.
If no problems are detected with the valve itself, the valve must be activated via the applicable test plan for the fault stored. Check the vehicle’s current I-level by either using AIR or the Key reader/ISPA NEXT application. If the current I-level is not already at 16-07-500 or higher, program the vehicle with the current version of ISTA.
Inspect the discharge point(s) of the tank ventilation valve using a borescope. The valves may have different reed valve designs. The reed valve dimple should be centered in the discharge point (see green arrow). The reed in this photo is good. Do not replace the valve.
The reed valve center with the vanes should be centered in the discharge port. The example shown here is good and does not need to be replaced.
In this example, the reed valve is no longer centered and is dislodged. This valve must be replaced.