B0939 BMW Fault Code

Description:

Vehicle Speed Sensor (VSS) Intermittent Indicates the powertrain control module (PCM) detected an error in the vehicle speed information. Vehicle speed data is received from either the vehicle speed sensor (VSS), transfer case speed sensor (TCSS), anti-lock brake system (ABS) control module, generic electronic module (GEM), or central timer module (CTM). This DTC is set the same way as B0939. However, it is intended to flash the transmission control indicator lamp (TCIL) for first time VSS circuit error/malfunctions. Refer to possible causes for B0939

B0939 Code Symptoms :

When you turn on the ignition, the Service Engine Soon or Check Engine B0939 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 B0939!

Diagnosis And Repairing B0939

B0939 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 B0939 code ?

• Clogged or faulty fuel injector (s)
• Intake Valve Timing Control Solenoid Valve circuit poor electrical connection
• Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code B0939, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code B0939 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.