Automatic Transmission Systems Flashcards

A faulty transmission range (TR) sensor is most likely to cause which combination of symptoms?

Answer: No-start in Park and incorrect gear indicator display

The TR sensor reports selector position for neutral-safety start and the gear indicator.

A technician checks a shift solenoid with an ohmmeter and reads 0 ohms. What does this indicate?

Answer: Shorted winding

A reading near 0 ohms means the coil windings are shorted together.

When an electronically controlled transmission goes into failsafe (limp) mode, what usually happens?

Answer: It stays in a fixed gear with maximum line pressure

Default mode de-energizes solenoids, leaving a single fixed gear and full line pressure to protect the unit.

What type of sensor is a transmission fluid temperature (TFT) sensor usually?

Answer: Negative temperature coefficient (NTC) thermistor

Most TFT sensors are NTC thermistors, so resistance drops as fluid temperature rises.

The TCM compares input (turbine) speed sensor and output speed sensor signals mainly to determine what?

Answer: Actual gear ratio and clutch slip

The ratio of input speed to output speed shows which gear is engaged and whether components are slipping.

After replacing a valve body or TCM, or after a battery disconnect, what procedure is often required?

Answer: Transmission adaptive relearn

Adaptive values are reset or no longer match the new parts, so a relearn restores proper shift quality.

What does generic DTC P0700 indicate?

Answer: The transmission control system has a malfunction, so check the TCM for specific codes

P0700 is a request from the TCM to turn on the MIL, which means separate TCM codes need to be retrieved.