Exam 11: Electronically Controlled Transmission

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?

Chrysler uses the difference between the input and the output shaft speeds to determine the CVI. This is used to adjust system pressures and shift timing.

Technician A says electronically controlled transmissions use Electronic Pressure Control (EPC) solenoids to control line pressure. Technician B says when looking at electronic pressure control solenoids with a digital storage oscilloscope (DSO); the voltage pattern would be a sine wave. Who is correct?

What unit of measure is often used to express the amount of intake air measured by the Mass Air Flow (MAF) sensor?

Two technicians are discussing electronically controlled automatic transmissions. Technician A says a Throttle Position Sensor (TPS) is supplied a reference voltage from the Powertrain Control Module (PCM). Technician B says most TPS's have a relatively high resistance at closed throttle, reducing the reference voltage. Who is correct?

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?

Which of the following sensors is used on a drive-by-wire vehicle to determine the driver's intent to accelerate or decelerate?

Two technicians are discussing electronically controlled automatic transmissions. Technician A says a Throttle Position Sensor (TPS) is supplied a steady 5V reference voltage from the Powertrain Control Module (PCM). Technician B says most Throttle Position Sensors (TPS) have high resistance at closed throttle, dropping most of the 5V reference voltage to near zero volts. Who is correct?

The ________ is a type of variable resistor called a potentiometer.

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?

Which of the following can cause an electronically controlled transmission to operate incorrectly?

Technician A says that on most vehicles if the Electronic Pressure Control (EPC) solenoid fails the vehicle will have high line pressure. Technician B says that if an EPC fails it will cause a delayed shift in most vehicles. Who is correct?

Technician A says that when a vehicle is determined to be under a light load, the PCM will not have the transmission will not delay the shifts. Technician B says that when a heavy load is determined from the MAP sensor, the PCM delays the transmission shifts. Who is correct?

Technician A says typically, an Engine Coolant Temperature (ECT) sensor will not read properly if the coolant is low. Technician B says a Cylinder Head Temperature (CHT) sensor will read correctly because it doesn't rely on coolant level. Who is correct?

The ________ is a type of variable resistor called a potentiometer.

Technician A says that automatic transmissions will change gear ratios based upon winter weather conditions. Technician B says that on a vehicle with traction control, the transmission will change shift programming to reduce wheel spin. Who is correct?

All of the following statements are true except:

On a hydraulically controlled automatic transmission, the computer can react to increased engine load only before the transmission shifts.

Manufacturers have found that by using torque management to reduce the amount of torque during shifting, they can _________.

Much of the wear and tear in an automatic transmission occurs during the relatively short time that the transmission is shifting between gears.