Ase A4 Practice Test. 80 Correctly Answered Questions Latest Update

63. A customer complains that his vehicle stalls repeatedly while parallel parking. Tech A says that the IAC valve is the most likely cause. Tech B says the power steering pressure sensor is at fault. Who is right? A. Tech A only B. Tech B only C. Both A and B D. Neither A and B {Ans: B. During parallel parking maneuvers, the Steering wheel is turned against the stops while the vehicle is relatively stationary. This causes high pressure in the power steering system, which places a load on the engine. The power steering pressure sensor informs the PCM/ECM of this high pressure, causing the PCM/ECM to in turn adjust the IAC valve to raise the engine idle speed. If the sensor is faulty, the PCM/ECM will not receive the signal and the engine will stall under the increased load. Tech A is wrong because if the IAC valve was faulty, the vehicle could stall at any time, and not just when parallel parking.}69. Tech A says an indirect measurement Tire pressure monitoring system uses wheel speed sensors to measure tire pressure. Tech B says a direct measurement TPMS uses tire pressure sensors to measure tire pressure. Who