What Causes the Electronic Brake System Fault Indicator Light to Illuminate?
3 Answers
Here are the reasons for electronic brake system fault issues: Severely Worn Brake Pads: Brake pads come in two types: those equipped with sensor wires and those without. For pads with sensor wires, when the brake pads wear down to the limit position, the sensor wire will automatically complete the circuit, triggering the fault indicator light. Low Brake Fluid Level: Insufficient brake fluid may be accompanied by significantly reduced braking force, and in severe cases, a complete loss of braking power. Under such conditions, the warning light will illuminate. Brake System Oil Leak or False Alarm: This can also affect the vehicle's technical performance, leading to wastage of lubricating oil and fuel, reduced power efficiency, compromised vehicle cleanliness, and environmental pollution. These issues may cause the fault light to turn on.
Once when I drove my decade-old car to the supermarket for groceries, the electronic brake fault light suddenly came on, which really startled me. There could be many possible reasons, such as the wheel speed sensor being covered with dust, affecting signal accuracy, or loose circuit connections, which are common in older cars. Low brake fluid level can also trigger this light, so I always keep a bottle of brake fluid in the car and first check the scale under the fluid cap. Insufficient battery voltage is another potential cause, as the system can't function properly without enough power, so it's best to test it with a voltmeter. If you feel the brakes becoming soft or sluggish while driving, you should pull over immediately to check, otherwise it could be dangerous on the highway. Daily maintenance is important—avoid driving on muddy roads for too long, and regularly clean the sensor areas when washing the car to save a lot of trouble.
I noticed that when the electronic brake indicator light comes on, it's probably due to some sensor or wiring issue, such as dirt on the wheel speed sensor or a loose connector. It could also be the ABS module acting up—like in a previous case I encountered, where restarting the car's power sometimes reset it. If the brake fluid reservoir is leaking or the level is low, the light will also come on as a reminder to top it off. If you're inclined to DIY, pop the hood and check the fuses related to the braking system in the fuse box—replace any blown ones. I also recommend inspecting the battery terminals for corrosion, as irregular voltage can trigger system errors. Before heading to the repair shop, check these points yourself to save unnecessary costs. For prevention, avoid prolonged driving through water, as it can easily short-circuit the sensors.
