U1957 BMW Fault Code

Description:

The input turbine speed sensor detects rotation of the input shaft of the input shaft speed sensor transmission. The computer uses that information, along with the output shaft speed sensor to determine if the transmission is operating according to plan. If the computer detects a difference between the input shaft speed , and the expected output shaft speed, it will adjust transmission pump pressure to prevent clutch disc slip. If adding pressure doesn't solve the problem, it will set a trouble code.

U1957 Code Symptoms :

When you turn on the ignition, the Service Engine Soon or Check Engine U1957 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 U1957!

Diagnosis And Repairing U1957

U1957 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 U1957 code ?

• Damaged VCT phaser
• Damaged ECM
• Fuel injector leaks
• Ignition misfiring

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code U1957, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code U1957 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.