U3994 BMW Fault Code

Description:

The issue covered by the bulletin involves a power steering noise/whine or fluid leak from the power steering pump, gear or high pressure side power steering hose during extreme low outdoor temperature operation.

U3994 Code Symptoms :

When you turn on the ignition, the Service Engine Soon or Check Engine U3994 light should flash briefly, indicating that the OBD system is ready to scan your vehicle for any malfunctions. After this brief flash, the light should stay off while you drive as long as no problems are detected. If so, you'll be glad to know that your vehicle is equipped with an early warning system that could save you time, money, and fuel in addition to helping protect the U3994!

Diagnosis And Repairing U3994

U3994 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 U3994 code ?

• Continuous oil flow to the VCT piston chamber
• Erratic camshaft position due to low oil pressure
• Faulty Air fuel ratio (A/F) Sensor 1 Bank 1
• Oil flow restriction in the oil passages or the variable camshaft timing (VCT) valve body