What Causes the Transmission Light to Illuminate?
3 Answers
Reasons for the transmission light to illuminate: 1. The transmission software has not been updated for a long time or there is a defect in the transmission software, causing the transmission warning light to turn on; 2. Damage to the transmission control unit preventing the vehicle from moving after shifting gears, which will also cause the warning light to illuminate; 3. Failure of internal transmission sensors resulting in the inability to move after shifting gears, which will trigger the transmission warning light; 4. Open circuits in the transmission wiring or poor communication, leading to the warning light turning on; 5. Damage to the internal gear shifting mechanism of the transmission, causing the transmission warning light to illuminate. When the transmission warning light comes on, the vehicle should be taken to a repair shop or a 4S dealership. Special diagnostic equipment should be used to access the transmission system and retrieve the fault memory. The fault codes stored in the memory should be checked, and repairs should be carried out based on the indications provided by the fault codes.
I've been driving automatic transmission cars for over a decade and have encountered the transmission warning light several times. The most common causes are insufficient or deteriorated transmission fluid, especially during summer traffic jams when the fluid temperature rises quickly - dirty fluid often triggers the light. Last time my warning light came on, I first checked the dipstick myself and found the fluid was black with a burnt smell, so I immediately had it changed. Another time it was due to a faulty solenoid valve, which caused noticeable jerking during gear shifts. If you keep driving with the warning light on, prolonged use may lead to transmission slippage or even serious damage. So when you see this light, don't hesitate - first check the fluid level and condition, then get it to a repair shop for safety.
Don't panic when the transmission warning light comes on. First, assess the vehicle's condition. If the engine RPM fluctuates abnormally, there's a lack of power during acceleration, or you experience particularly strong gearshift jerks, there's an 80% chance it's an internal transmission issue. My old car once had clogged oil passages – like when metal debris blocked the oil pump filter screen, triggering low oil pressure warnings. Modern cars with more electronic systems may give false alarms due to sensor failures; using an OBD scanner to check trouble codes is the quickest solution. Remember, during cold winter starts, low oil temperature may briefly illuminate the warning light. If it turns off after the engine warms up, there's no need to worry.
