Automatic and CVT Transmission Diagnostics Quiz

During a road test, a CVT-equipped vehicle exhibits “flaring” (sudden engine RPM increase) under load. What is the most likely root cause?

• Faulty throttle position sensor

• Worn primary pulley bearing

• Slipping steel belt within the CVT

• Incorrect tire pressure

A DSG transmission logs intermittent P2711 (Unexpected Mechanical Gear Disengagement). Which subsystem is most likely at fault?

• ABS module

• Mechatronic unit

• Output shaft bearing

• Brake pedal switch

In a CVT, what effect does incorrect pulley pressure regulation have on performance?

• Improved torque delivery

• Overheating of differential

• Loss of gear ratio control and potential belt damage

• Increased engine braking

Which of the following is true about a dual-clutch transmission during a low-speed maneuver, such as parallel parking?

• Both clutches are fully engaged

• The system enters neutral mode

• Controlled clutch slippage simulates torque converter creep

• A single-gear bypasses the clutch

If an automatic transmission experiences a delay in engaging reverse, which fault is most plausible?

• Faulty O2 sensor

• Insufficient line pressure due to a worn pump

• Worn valve stem seals

• Radiator cap failure

Which component is primarily responsible for directing hydraulic fluid to the correct clutches and bands in a traditional automatic gearbox?

• Output shaft

• Torque converter

• Valve body

• Sun gear

The lock-up clutch in a torque converter engages at cruising speeds to:

• Increase oil pressure in the torque converter

• Prevent gear hunting

• Create a direct drive connection between engine and transmission

• Allow regenerative braking

How does a worn input speed sensor affect DSG transmission behaviour?

• Gear stick becomes inoperable

• System remains in limp mode with delayed shifts

• Reverse gear is disabled

• Fuel economy improves significantly

Which pressure test reading would suggest a leaking clutch pack in an automatic transmission?

• Pressure within spec at idle

• Sudden drop during gear engagement

• Pressure increases with engine speed

• Consistent high pressure

If the line pressure solenoid fails in a CVT system, what is the most likely result?

• Accurate gear ratio adaptation

• Reduced driveability and ratio control failure

• Transmission enters sport mode

• Clutch packs become over-pressurised