What Causes the ABS Light to Illuminate in a Buick GL8?

[SanChloe]

ABS light illumination can occur in various states, each with different causes and solutions, as detailed below: State 1: ABS warning light remains constantly illuminated (most common). Cause 1: The ABS wheel speed sensor's sensing area is covered by dirt, mud, or other contaminants, affecting its ability to detect the corresponding speed signal. This prevents the ABS control module from determining the vehicle speed or wheel slip rate, thus failing to issue appropriate commands to regulate braking. Solution: Clean the contaminants from the wheel speed sensor and adjust the gap between the sensor and the tone ring to restore normal function. Cause 2: Poor signal transmission due to loose system wiring connections or faulty ABS relay contacts, leading to system malfunction. Solution: Inspect wiring connections and reconnect any loose components. State 2: ABS warning light intermittently illuminates but turns off during acceleration. Cause: When multiple electrical devices are in use, the battery voltage drops below 10.5V. As engine speed increases, voltage rises, causing the ABS light to turn off. This may also occur due to insufficient ABS system power supply voltage, such as poor terminal contact or grounding issues. Solution: Check battery specific gravity; inspect the charging system; examine the power supply (e.g., voltage relay or poor power contact). State 3: ABS warning light remains illuminated after engine start and only turns off when the engine is turned off (IGFF). Cause: Poor grounding connection of the ABS hydraulic valve body; faulty wiring connector of the ABS hydraulic valve body; ABS control module malfunction. Solution: Loosen and retighten the hydraulic valve body grounding screw, cleaning the contact surface if necessary; check for enlarged connector gaps; replace the ABS or ABS/ASR control module. State 4: ABS warning light illuminates during high-speed driving. Cause: The ABS control module detects a significant discrepancy between rear and front wheel speed signals during high-speed driving; incorrect tire or wheel rim specifications. Solution: Refer to the vehicle's tire and wheel rim specifications, as indicated on the label near the fuel filler cap. State 5: ABS warning light intermittently illuminates. Cause: Improper adjustment of the brake light switch; poor internal contact of the brake light. Solution: With the engine running, press the brake pedal and manually push the brake switch linkage fully downward, then release the pedal to complete self-positioning; replace the brake light switch if necessary. If the ABS warning light is illuminated, it is advisable to avoid continued driving. An illuminated ABS light indicates a malfunction in the anti-lock braking system. During emergency braking, wheel lock-up may occur, causing the vehicle to skid uncontrollably and preventing the driver from decelerating or adjusting the vehicle's trajectory, posing significant safety risks.