What Causes All Snowflake and S Lights to Illuminate in an Automatic Transmission?
2 Answers
Low outdoor temperature or signal transmission errors can cause the snowflake light to illuminate; the S light may come on due to faults in the engine or transmission. Detailed reasons for both the snowflake and S lights illuminating in an automatic transmission vehicle include: Transmission fluid: If the quality of the transmission fluid is abnormal, it may damage the solenoid valve, causing both the snowflake and S lights to illuminate. Pressure valve and lock-up valve: If the two pressure valves and the clutch lock-up valve malfunction, or if the gear control valve fails, it can also result in both the snowflake and S lights illuminating. Outdoor temperature: The outdoor temperature display shows that the snowflake light does not illuminate above 4°C, a yellow snowflake light appears between 4°C and 0°C, and a red snowflake light appears below 0°C.
Recently, my automatic transmission car also had the issue of the snowflake light coming on, which was quite a hassle. The snowflake light is actually an indicator for the snow/slip prevention mode. If it stays fully illuminated, it could indicate an internal transmission fault, such as inaccurate sensor signals, especially in extremely cold weather when sensors are prone to malfunction. It could also be due to aging wiring causing a short circuit or the control computer falsely reporting a fault code. I must remind you to first check the owner's manual to confirm if it's a normal mode. If the light doesn't go off after restarting the vehicle, immediately contact a professional shop for diagnosis using a scanner. Don't delay, because continuing to drive may affect the car's traction control, making it prone to skidding on slippery roads.
