Question 1

Technician A says the Engine Coolant Temperature (ECT) sensor is not like the Transmission Fluid Temperature (TFT) sensor. Technician B says the Powertrain Control Module (PCM) or Transmission Control Module (TCM) uses the ECT to vary shift timing and pressure based on engine temperature. Who is correct?

Accepted Answer

The ECT sensor is used by the PCM or TCM to vary shift timing and pressure based on engine temperature.

Question 2

Which of the following is used on electronically controlled automatic transmissions in place of the vacuum modulator valve?

Accepted Answer

The Manifold Absolute Pressure (MAP) sensor is used in electronically controlled automatic transmissions to measure engine load, which replaces the function of the vacuum modulator valve in older systems.

Question 3

Technician A says on computerized transmissions, an Electronic Pressure Control (EPC) solenoid is used to control line pressure. Technician B says most EPC solenoids are pulse-width modulated. Who is correct?

Accepted Answer

Technician A is correct because EPC solenoids are indeed used to control line pressure in computerized transmissions. Technician B is also correct because most EPC solenoids are pulse-width modulated to precisely control the pressure.

Question 4

If the maximum line pressure available in a transmission was 200 PSI, and the Electronic Pressure Control (EPC) solenoid is at 50% pulse width, what pressure reading would you expect on a gauge installed in the line pressure test port?

Accepted Answer

The EPC solenoid at 50% pulse width modulation would typically regulate the line pressure to approximately 50% of the maximum available pressure, which is 100 PSI in this case.

Question 5

What can be calculated by the Powertrain Control Module by comparing the input shaft speed sensor and output shaft speed sensor?

Accepted Answer

The Powertrain Control Module can calculate both the gear ratio and detect clutch or band slippage by comparing the input and output shaft speed sensors.

Question 6

Technician A says the Torque Converter Clutch (TCC) solenoid is monitored by the Powertrain Control Module (PCM) and Diagnostic Trouble Codes can be set when the TCC is not operating correctly. Technician B says on hydraulically controlled transmissions, the PCM will not set codes unless the TCC circuit is open or shorted, or the solenoid is shorted. Who is correct?

Accepted Answer

Both technicians are correct. The PCM monitors the TCC solenoid and can set trouble codes if there are issues with its operation, such as being open, shorted, or not functioning correctly.

Question 7

Technician A says the Powertrain Control Module (PCM) can reduce transmission wear by torque reduction during gear shifting. Technician B says the PCM monitors gear ratios as a method of fault detection. Which technician is correct?

Accepted Answer

The PCM can indeed reduce transmission wear by managing torque during shifts (Technician A), and it also monitors gear ratios to detect faults (Technician B).

Question 8

In a _______ controlled transmission, the shift points are controlled by hydraulic and mechanical devices such as springs and valves.

Accepted Answer

In a hydraulically controlled transmission, the shift points are managed by hydraulic and mechanical devices like springs and valves, rather than electronic or electrical systems.

Question 9

The PCM varies the shift timing and pressures based on changes from this thermistor sensor.

Accepted Answer

The PCM (Powertrain Control Module) uses the fluid temperature sensor to adjust shift timing and pressures, as the transmission fluid temperature affects the viscosity and performance of the fluid.

Question 10

Technician A says that a TPS signal is an important input used by the PCM to determine transmission operation. Technician B says that scan tool data is the best way to verify TPS operation. Who is correct?

Accepted Answer

The answer of Technician A says that a TPS signal...

Question 11

Technician A says that a quick depressing of the accelerator pedal could indicate more power and a need for a downshift and delayed upshifts. Technician B says that a quick release of the throttle pedal could indicate more power and a need for a downshift and delayed upshifts. Who is correct?

Accepted Answer

Technician A is correct because a quick depressing of the accelerator pedal signals the need for more power, prompting the transmission to downshift and delay upshifts to provide better acceleration.

Question 12

The sensor responsible for sending a signal that indicates the amount of load on an engine is the:

Accepted Answer

The MAP sensor (Manifold Absolute Pressure) is responsible for sending a signal that indicates the amount of load on an engine.

Question 13

Technician A says that the MAF sensor measures the mass of the incoming air. Technician B says that a MAF is used because the more air entering the engine means the harder an engine is working. Who is correct?

Accepted Answer

Technician A is correct because the MAF (Mass Air Flow) sensor measures the mass of the incoming air to the engine. Technician B is also correct because the MAF sensor helps determine the engine load by measuring the amount of air entering the engine, which correlates with how hard the engine is working.

Question 14

The PCM uses the __________ to determine engine speed.

Accepted Answer

The CKP (Crankshaft Position Sensor) is used by the PCM (Powertrain Control Module) to determine engine speed by monitoring the position and rotational speed of the crankshaft.

Question 15

Technician A says that the input shaft speed sensor is compared to the crankshaft position sensor to determine slippage between the turbine and the impeller. Technician B says that the CKP sensor is used to monitor engagement of the torque converter clutch. Who is correct?

Accepted Answer

The answer of Technician A says that the input shaft...

Question 16

Technician A says that the brake light switch may be a separate switch from the brake on/off switch. Technician B says that the brake switch may also be used to put the vehicle transmission in neutral. Who is correct?

Accepted Answer

Both technicians are correct. The brake light switch may be a separate switch from the brake on/off switch, and it may also be used to put the vehicle transmission in neutral.

Question 17

Technician A says that as soon as the brake pedal is depressed, the TCC is released to prevent drag and engine stalling. Technician B says that when the brake pedal is depressed, the PCM engages the TCC. Who is correct?

Accepted Answer

Technician A is correct. When the brake pedal is depressed, the Torque Converter Clutch (TCC) is typically released to prevent drag and engine stalling.

Quiz 11: Electronically Controlled Transmission