What Causes All Car Warning Lights to Illuminate?
2 Answers
The reasons for all car warning lights illuminating are: 1. ECU CAN bus malfunction or poor contact at the ECU CAN interface; 2. Excessive dirt and carbon deposits causing abnormal air flow, preventing accurate control of normal air intake and resulting in unstable gas content; 3. Low fuel pressure combined with poor constant pressure performance leads to low system atomization levels, making the car difficult to start. Solutions for all car warning lights illuminating: 1. Check if there are any issues with the battery terminals, disconnect and reconnect the negative terminal, then start the car; 2. Measure the generator's output voltage—if it's around 14V, it indicates the issue is not insufficient generator output; 3. Use a diagnostic tool to read fault codes and narrow down the analysis scope based on the codes.
With thirty years of driving experience, I've encountered numerous instances where all the warning lights were on. The main causes I've identified include unstable or aging battery voltage, insufficient alternator output leading to false computer alerts, loose or damp connectors causing signal interference, collective sensor failures such as wheel speed sensors or oxygen sensors malfunctioning, control module crashes requiring a system reboot, or potential ECU program errors needing a reflash. If you encounter this situation, don't panic. First, safely pull over and turn off the engine for ten minutes to allow the vehicle to power cycle and reset. If the lights remain on after restarting, avoid driving further and immediately use a diagnostic tool to read the trouble codes—that's the correct approach.
