What causes the ABS light to come on in a Peugeot 308?
3 Answers
There are various states in which the ABS light may illuminate, with different causes and solutions for each state. The details are as follows: State 1: ABS warning light remains constantly on (most common). Cause 1: The ABS wheel speed sensor's sensing area is covered by dirt, mud, or other contaminants, affecting the sensor's ability to detect the corresponding speed signal. This prevents the ABS computer from determining the vehicle speed and calculating the wheel slip rate, thus failing to issue appropriate commands to adjust braking. Solution: Clean the dirt from the wheel speed sensor and adjust the gap between the sensor and the signal ring to restore normal function. Cause 2: Loose connections in the system wiring or poor contact in the ABS relay can lead to signal issues, causing system failure. Solution: Check the wiring connections and reconnect any loose parts. State 2: The ABS warning light intermittently illuminates but turns off when accelerating. Cause: When multiple vehicle electrical components are in use, the battery voltage may drop below 10.5V. As the engine speed increases and the voltage rises, the ABS warning light turns off. This can also occur if the ABS system power supply voltage is too low due to poor terminal contact or grounding issues. Solution: Check the battery's specific gravity, inspect the charging system, and verify the power supply (e.g., voltage relay or poor power contact). State 3: The ABS warning light remains on after engine startup and only turns off when the engine is turned off (IGFF). Cause: Poor grounding contact in the ABS hydraulic valve body, loose wiring connections in the ABS hydraulic valve body, or a faulty ABS computer. Solution: Loosen and then retighten the grounding screw on the hydraulic valve body, cleaning the contact surface if necessary. Check if the connector gaps have widened. Replace the ABS or ABS/ASR computer if needed. State 4: The ABS warning light illuminates during high-speed driving. Cause: During high-speed driving, the ABS computer detects a significant discrepancy between the rear and front wheel speed signals. This may also occur if the tire or wheel rim specifications are incorrect. Solution: Refer to the vehicle's tire and wheel rim specifications, as indicated on the label near the fuel tank cap. State 5: The ABS warning light intermittently illuminates. Cause: Improper adjustment of the brake light switch or poor internal contact in the brake light. Solution: With the engine running, press the brake pedal and use a finger to push the brake switch linkage fully downward. Release the brake pedal to complete the self-setting position. Replace the brake light switch if necessary. If the ABS warning light is on, it is recommended not to continue driving, as this indicates a fault in the vehicle's anti-lock braking system. During emergency braking, if the wheels lock up, the vehicle may skid uncontrollably, making it difficult for the driver to slow down or adjust the vehicle's trajectory, posing significant safety risks.
When I saw the ABS light on my Peugeot 308 illuminate, my first thought was that it might be due to a few common issues. The wheel speed sensor is the most susceptible to getting dirty or worn out by mud and water on the road. Located near the wheel, if it fails to accurately sense speed, the light will come on. Electrical circuit problems are also common, such as a blown fuse cutting off power or aged wiring and loose connections causing signal loss. If the ABS control module malfunctions, that's a major issue—it will display error codes and require computer diagnostics. Related to the braking system, low or old brake fluid levels can also trigger the light. Most critically, an illuminated ABS light means the wheels might lock up during emergency braking, especially in rainy or snowy conditions, increasing the risk of skidding and accidents. So, don't delay—head straight to a 4S shop or professional repair center to get it checked. Safety first, after all.
My Peugeot 308's ABS light suddenly came on, which really worries me about driving safety. This light indicates the anti-lock braking system may have failed, causing wheels to lock up and skid during emergency braking - especially dangerous with family in the car. Common causes include dirty or damaged sensors (particularly the wheel speed sensors near the wheels that can get splashed with mud). Electrical issues like blown fuses or broken wiring can prevent signal detection. If the ABS module itself fails, it requires repair or replacement. I recommend stopping driving immediately - first check if brake fluid is low or needs replacing due to age, then try restarting the engine to see if the light resets. For safety, get to a repair shop ASAP for comprehensive diagnostics, especially before encountering wet/slippery road conditions.
