Automatic Transmission/Transaxle Flashcards

A P0730 'incorrect gear ratio' code with no slipping feel most likely results from which fault?

Answer: Mismatched input/output speed sensor readings

The module compares input and output speeds; a sensor or wiring fault triggers a ratio error even without slip.

Which type of clutch in an automatic transmission uses fluid pressure acting on a piston to compress friction discs?

Answer: Multiple-disc clutch

A multiple-disc clutch is applied hydraulically by a piston that squeezes the friction and steel plates together.

A one-way (overrunning) clutch in a transmission is designed to do what?

Answer: Transmit torque in one direction and freewheel in the other

An overrunning clutch locks to drive in one direction and freewheels in the opposite direction for smooth shifts.

When servicing a transmission with a 'lifetime' fluid that is dark and burnt, the technician should do what?

Answer: Inform the customer and service per condition/symptoms

Burnt fluid signals damage or overheating; the customer should be informed and the unit serviced based on condition.

Excessive line pressure in an automatic transmission most commonly causes which symptom?

Answer: Harsh, firm shifts

Too-high line pressure applies clutches and bands too aggressively, producing harsh shifts.

Which transmission component converts the rotational input from the engine into hydraulic pressure for the system?

Answer: Oil pump

The oil pump, usually driven by the converter hub, generates the hydraulic pressure the transmission needs.

A solenoid that controls torque converter clutch apply is electrically commanded by which component?

Answer: Powertrain control module (PCM/TCM)

The PCM/TCM energizes the TCC solenoid based on speed, load, and temperature inputs.