What does the car plus-minus light indicate as a fault?
4 Answers
When the car's plus-minus light is illuminated, it indicates that the generator's output voltage is lower than the battery voltage, the generator is not working, or there is a fault in the power supply circuit. At this time, the vehicle is running on battery power, and it is advisable to have it inspected and repaired at a service center as soon as possible. Like all batteries, if the generator and charging circuit do not charge, the car's battery will eventually run out of power, leading to the vehicle's inability to operate normally. Common car warning lights include the following: Tire Pressure Warning Light: A yellow symbol featuring an irregular circle that is not closed at the top, with four small spikes at the bottom and an exclamation mark inside. This symbol indicates abnormal tire pressure, and the tires should be checked promptly. Coolant Temperature Indicator: This light usually stays on when the car is first started, especially in winter. It has a blue thermometer-like design and will illuminate if the coolant temperature is too high or too low. Some vehicles have a temperature gauge on the dashboard with a needle that rises or falls with the coolant temperature. If the coolant temperature is too high, do not continue driving; stop immediately and wait for the temperature to normalize before heading to the nearest 4S shop or auto repair shop for inspection. Oil Pressure Indicator: An icon on the dashboard resembling a "kettle" shape is the oil pressure indicator, which lights up when there is an abnormality in oil pressure. The oil pressure indicator will illuminate when the vehicle is started. If the oil pressure is normal, it will turn off shortly after. If there is an abnormality, it will remain lit. Brake System Warning Light: A red icon with a circle in the middle containing an exclamation mark. This indicates a problem with the brake system, such as low brake fluid level or the handbrake being engaged.
Seeing that plus-minus light on the car dashboard lit up makes me a bit uneasy because it's definitely not normal! It could be an issue with the transmission gear sensor or the control unit. From my experience driving different car models, a common problem is dust or moisture getting near the gearshift lever, causing signal interference and making the light turn on mistakenly. Sometimes, bumps while driving can also loosen wire connections, affecting the system's judgment. Ignoring it might cause the car to enter an incorrect mode, like suddenly downshifting or failing to accelerate—how dangerous! I remember once driving long-distance on a mountain road when the light came on, and I didn’t dare continue—I found a safe spot to stop and check. I recommend everyone pay attention to the dashboard status regularly, clean interior gaps periodically to prevent small issues from becoming big ones. It’s best to take it directly to a professional repair shop for inspection to avoid dragging out major trouble.
As someone who frequently modifies cars, I think the abnormal illumination of the plus/minus lights is most likely due to a signal fault in the Transmission Control Module (TCM). It could be caused by aging sensors or incorrect data reading, making the system mistakenly think you've switched to manual mode. Simply put, it's like a computer crash—try restarting the engine to see if it resets. If the lights still flash, you'll need a diagnostic tool to read the trouble codes, such as the P0700 series. Don’t mess with the wiring yourself, as it can easily damage the circuit board. A related topic is that unprofessional wiring during electrical modifications can easily cause short circuits, leading to this issue. So, be careful when modifying your car and seek help from experienced professionals to protect your car’s core components. Remember, safety comes first—avoid system malfunctions at high speeds, which could cause excessive acceleration or jerking, damaging the car.
The gear shift indicator light staying on is quite annoying. I usually turn off the engine and restart to see if it goes off. If it doesn't, check if the related fuse in the fuse box is blown. Then inspect around the gear lever for any obstructions that might affect the signal. If the wiring connectors are loose, try reinserting them firmly, but avoid pulling too hard to prevent damage. Most of the time, it's a minor issue that you can handle yourself. Related tip: Moisture during rainy days can cause poor contact, so parking in a ventilated garage helps reduce risks. If you can't fix it, get it repaired promptly to avoid delays.
