What Does It Mean When the Dashboard Plus-Minus Light Comes On?
3 Answers
The illumination of the plus-minus light on the dashboard indicates that the generator voltage is lower than the battery voltage, resulting in a power supply circuit malfunction. At this time, the vehicle is running on battery power, and the generator should be inspected and repaired at a repair shop as soon as possible. Below are specific details about car batteries: 1. Classification of Batteries: Car batteries are divided into maintenance-free batteries and conventional batteries (lead-acid batteries). Most models currently use maintenance-free batteries, while many Japanese cars use conventional batteries. The electrodes of conventional batteries are made of lead and lead oxide, with the electrolyte being an aqueous solution of sulfuric acid. Their lifespan is generally around 2 years, so replacing them every two years is most reasonable. 2. Regular Maintenance: To extend the battery's lifespan, regular maintenance and good driving habits are necessary. When the electrolyte level is insufficient, the battery may not hold a charge, requiring timely refilling. After turning off the car, ensure all lights are turned off to avoid excessive battery drain leading to a dead battery. If the car is parked for an extended period, it is recommended to disconnect the battery's negative terminal to cut off power, preventing a dead battery. It is best to start the car once a week, allowing the battery to charge via the internal generator while the engine idles, ensuring sufficient power for the next start.
I previously encountered a situation where the plus and minus lights on the dashboard came on while driving, which is usually the manual mode indicator light of the automatic transmission activating. This indicates that the vehicle has entered manual shifting mode, possibly because you accidentally pressed the paddle shifters or steering wheel buttons, or the gear lever was moved to the M position. Many modern cars are designed with this feature to allow drivers to manually control gear shifting for enhanced driving pleasure. If the lights come on without you switching modes, it could be due to a stuck button or a sensor malfunction. If it remains on for a long time, while not directly dangerous, it may affect transmission performance, such as increased fuel consumption or uneven acceleration. I recommend first checking if the gear shifting operation is normal, then repeatedly switching to automatic mode after parking to reset the system. If the issue persists, visit a professional shop to inspect the wiring and ECU settings to prevent further complications. Overall, it's not a major concern—just a minor hiccup in daily driving that can be resolved with timely attention.
Last time the plus/minus light on my Corolla's dashboard came on, I got nervous at first, thinking the car was broken. Turned out I'd accidentally brushed against the steering wheel paddle shifters. This light is common in automatic transmission models, indicating you've activated manual mode to control gear shifts yourself. If the light stays on without reason, it might be due to poor button contact or aging wiring causing false signals; occasionally, pressing the reset button a few times can turn it off. Don't worry too much—it doesn't significantly impact driving safety. However, if it stays on, the car might default to lower gears, increasing fuel consumption or noise. I make a habit of checking settings when starting the car to avoid accidental activation. If needed, have a friend test the button's voltage with a multimeter—it's a cheap fix. Overall, it's just a reminder for a convenient feature; no need to panic. Stay calm and drive on.
