ASE A2 Automatic Transmission Practice Test
51. An automatic transmission will not upshift and has fault code P0755, indicating a Shift Solenoid B Malfunction. Technician A says this could be caused by a sticking shift solenoid. Technician B says the shift solenoid is faulty. Replace the solenoid and erase the code from the TCM with a scanner. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
Answer A is correct. Unchanged and contaminated ATF covers the transmission case and internal components with tarnish and debris. It clogs solenoids and valves, causing them to stick. A sticking solenoid will cause a vehicle to remain in gear or neutral.
Answer B is wrong. Inspect and test the solenoid and circuit with a scanner and a multimeter before replacement.
Answer C is wrong. Technician A is correct. Learn more about shift solenoids in the Read more... section.
Answer D is wrong. Technician A is correct.
52. A torque converter's stator:
- A. Should spin freely in both directions.
- B. Spins freely until the torque converter reaches its coupling phase.
- C. Is fastened to the impeller.
- D. Has a one-way clutch that allows the stator to spin freely in one direction but keeps it from rotating in the other.
Answer A is wrong. If the stator spins freely in both directions or if it's locked in both directions, it's bad and needs replacement.
Answer B is wrong. If the stator's one-way clutch spins freely at low speeds, there will be a loss of torque multiplication, resulting in poor low-speed performance.
Answer C is wrong. It is not fastened to the impeller.
Answer D is correct. A stator has a one-way clutch that allows it to spin freely in one direction but keeps it from rotating in the other.
53. Which transmission pump changes its flow rate to meet the needs of an automatic transmission?
- A. A diaphragm positive displacement pump.
- B. A fixed-displacement crescent gear pump.
- C. A variable-displacement vane pump.
- D. A fixed-displacement rotor pump.
Answer A is wrong. A diaphragm positive displacement pump is not a variable-displacement automatic transmission pump.
Answer B is wrong. The most common type of gear pump is the crescent pump. These pumps have two gears like other gear pumps, but they are designed with an outer gear with internal teeth and a smaller inner gear with external teeth. As these teeth mesh, they carry with them and force fluid from the inlet port to the outlet port.
Answer C is correct. A variable-displacement/rate transmission pump changes its flow rate according to the needs of the transmission. This pump saves on wasted energy and power.
Answer D is wrong. A rotor-type pump is similar to a crescent gear pump, except it utilizes rotors instead of gears.
54. The transmission's 1-2 shift valve is sticking in its bore. Use all of the following to clean and dry this shift valve EXCEPT:
- A. A lint-free cloth.
- B. Compressed air.
- C. A varnish removing agent.
- D. Shop rags.
Answer A is wrong. Clean the valves with a varnish removing agent and carefully dry them with compressed air and a lint-free cloth.
Answer B is wrong. Tarnish forms from heat and oxidation. It coats the inside of the transmission with a brown colored goo. Use a cleaning agent and a lint-free cloth to remove tarnish from components like the valves, springs, and their corresponding bores.
Answer C is wrong. The tarnish can be seen on the transmission's fluid level dipstick. It's essential to monitor and change the transmission fluid at recommended intervals.
Answer D is correct. Shop rags leave lint and residue on the valve's surface. Use a lint-free cloth or compressed air to dry the valve body and valves.
55. A vehicle's automatic transmission is not downshifting correctly. A vacuum hose is detached and hanging down by the transmission pan. This vacuum hose should be connected to which of the following?
- A. The Governor.
- B. The Throttle Position Sensor.
- C. The Modulator.
- D. The Vehicle Speed Sensor.
Answer A is wrong. Governors are used in hydraulically controlled transmissions to indicate vehicle speed.
Answer B is wrong. A throttle position sensor is used in today's electronically controlled transmissions to indicate load. They replace the modulators used in older transmissions.
Answer C is correct. A modulator is a vacuum controlled device that controls throttle pressure.
Answer D is wrong. Vehicle speed sensors replace the governor in older hydraulic transmissions.