Why does the Buick ambient temperature always display -40 degrees?
2 Answers
Buick ambient temperature always displaying -40 degrees is due to a faulty outdoor temperature sensor. Fault manifestations: When the sensor is clogged with carbon particles, the oxygen sensor's signal voltage will be high, causing the engine computer to issue a command to reduce fuel injection, resulting in an overly lean air-fuel mixture. When dust and engine oil block the oxygen sensor's air vent, the oxygen sensor's signal voltage will be low, and the engine voltage will instruct the fuel injector to inject more fuel, causing an overly rich air-fuel mixture. Causes of sensor failure: The most important thing is to pay attention to fuel quality and try to avoid refueling at small gas stations, especially those in highway service areas. Check whether the spark plugs and ignition coils are operating at normal voltage. Inspect the three-way catalytic converter to ensure it is functioning properly and not clogged.
When driving my Buick, I encountered an issue where the ambient temperature always displayed -40 degrees. This is usually caused by a malfunction of the ambient temperature sensor located at the front of the vehicle. The sensor is positioned near the front grille and can easily get clogged by flying stones, insects, or mud, leading to signal errors. It could also be due to aging or damage of internal components in the sensor, or short circuits and disconnections in the wiring caused by moisture corrosion. The system sets -40 degrees as the default error value to alert the driver. While driving, this can affect the automatic control of the air conditioning, making it less cool in summer and less warm in winter, which is particularly uncomfortable during long drives. I tried cleaning the sensor probe with a soft cloth myself, but the effect was temporary. Later, at a repair shop, they detected a short circuit caused by damaged wiring. After replacing the sensor, everything returned to normal. I recommend Buick owners address similar issues early to avoid affecting overall driving comfort and air conditioning efficiency. Having the sensor area checked by a technician during regular maintenance can also prevent problems.
