U04B1 BMW Fault Code

Description:

The Throttle Position sensor signals the Engine Control Module as to the current position of the engine throttle valve.
The current throttle valve opening is based on the driver's input from the gas pedal.

The ECM uses the information from this sensor to help calculate fuel delivery and spark timing.

U04B1 Code Symptoms :

When you turn on the ignition, the Service Engine Soon or Check Engine U04B1 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 U04B1!

Diagnosis And Repairing U04B1

U04B1 OBD 2 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.

How to fix U04B1 code ?

• Faulty Air Flow Meter
• EVAP system hose leaking
• Ignition coils circuit poor electrical connection
• Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code U04B1, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code U04B1 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.