Automobile & Light Truck Certification Test A5 BrakesAnti-lock Brake System (ABS) Diagnosis and RepairMedium
A vehicle equipped with traction control experiences a loss of traction on a slippery surface. The driver notices the traction control light flashing and feels a slight vibration. What action does the traction control system primarily take to regain traction in this scenario?
- AIncreases engine RPM to provide more power to the slipping wheel.
- BApplies brake pressure to the slipping wheel and/or reduces engine power.
- CActivates the anti-lock braking system on all four wheels simultaneously.
- DEngages the differential lock to distribute power evenly to both wheels.
Show answer & explanationAnswer & explanation
Correct answer: B. Applies brake pressure to the slipping wheel and/or reduces engine power.
Traction control systems work by detecting wheel spin and then selectively applying brake pressure to the spinning wheel(s) and/or reducing engine power to regain grip. This prevents excessive wheel slip and maintains vehicle stability.
Why the other options are wrong
- A. Increasing engine RPM would worsen wheel spin, not improve traction.
- C. Activating ABS on all wheels would stop the vehicle, not help it regain traction while moving.
- D. Engaging a differential lock is a separate feature, typically found on 4WD/AWD vehicles, and not a primary action of a standard traction control system.
Traction Control System (TCS)
An active safety system that prevents loss of traction of driven wheels by detecting wheel spin and applying corrective measures.
- Uses wheel speed sensors to detect differences in wheel speed.
- Primarily applies brakes to slipping wheels and/or reduces engine power.
- Helps maintain stability during acceleration on slippery surfaces.
Memory trick: When wheels spin, TCS steps in, braking and cutting power to win!