Practice Test Flashcards

You will conduct all of the tests listed below while conducting preliminary diagnostics on an electronically controlled automatic transmission, EXCEPT:

Answer: Flex plate check

Preliminary diagnostics for an electronically controlled automatic transmission typically focus on assessing the transmission's basic operational health and fluid condition. This includes checking fluid levels, performing a line pressure test to evaluate hydraulic integrity, and conducting a stall test to check torque converter and clutch engagement. A flex plate check, while important for the engine-to-transmission connection, is generally not part of routine preliminary transmission diagnostics and is usually performed if specific symptoms indicate an issue with that component.

Which of the following diagnostic techniques, which doesn't require manufacturing electrical standards, is the best for figuring out whether you have a bad fuel injector?

Answer: Determine if all injectors have the same electrical resistance

Fuel injectors are electromagnetic solenoids, and their internal electrical resistance is a key indicator of their health. By measuring the electrical resistance across the terminals of each injector and comparing it to specifications or other injectors, a technician can quickly identify an open circuit, a short circuit, or significant internal wear. This method is effective for diagnosing electrical faults without needing to operate the engine or use specialized electrical standards.

These claims about an air conditioning performance test are all accurate EXCEPT for:

Answer: To avoid evaporator odor, you want to operate the AC in RECIRC instead of FRESH

Operating the AC continuously in RECIRC mode can actually contribute to evaporator odor. This mode recirculates stale cabin air and moisture, creating a damp environment on the evaporator fins that promotes the growth of mold and mildew. To help prevent odors, it's often recommended to periodically use FRESH air mode, especially before shutting off the vehicle, to introduce drier outside air and help dry out the evaporator.

Someone expresses concern about their car's harsh shifting. First gear is when it's most noticeable. The first speed-blocking ring, according to technician A, is the most likely culprit. Technician B decides that the clutch needs an adjustment. Who is accurate?

Answer: Technician B

Technician B is accurate. Harsh shifting, particularly noticeable in first gear of a manual transmission, is a common symptom of an improperly adjusted clutch. If the clutch does not fully disengage, it can cause grinding or difficulty in selecting gears. While a worn blocking ring can cause shifting issues, a clutch adjustment is a more fundamental and frequently overlooked cause of harsh shifting.

What is the most likely reason if you hear a flapping noise towards the front of an engine?

Answer: Timing belt tension is too loose

A flapping noise originating from the front of the engine is often indicative of a loose timing belt. If the timing belt tensioner is faulty or the belt itself is stretched, it can lose proper tension, causing it to vibrate excessively and create a distinct flapping sound. This condition is critical as a loose timing belt can jump teeth, leading to severe engine damage.

With the temperature selector set to cool and the vent position, incoming air is heated. What could be the issue?

Answer: Air blend door is stuck

The air blend door controls the mix of hot and cold air entering the cabin from the heater core and evaporator. If the temperature selector is set to cool but only heated air is coming out, it indicates that the blend door is stuck in a position that allows hot air to bypass the cooling process. This prevents the HVAC system from delivering the desired cool air, regardless of other settings.

All of the following could happen if the automatic transmission selection linkage is misaligned, WITH THE EXCEPTION of:

Answer: Leak at converter hub

Automatic transmission selection linkage misalignment primarily affects the transmission's ability to correctly engage gears, leading to symptoms like poor gear engagement, incorrect gear indicator readings, or even low fluid pressure if the manual valve isn't fully seated. A leak at the converter hub, however, is typically caused by issues with the torque converter seal, pump bushing, or the converter itself, and is not a direct consequence of linkage misalignment.

Before performing an engine compression test, the fuel injection and ignition systems must be turned off for a variety of reasons. Which of these is the least significant justification?

Answer: Prevents inaccurate readings

Turning off the fuel injection and ignition systems during a compression test is primarily for safety and preventing damage. It prevents fuel from being injected (reducing fire risk and preventing cylinder wash-down) and disables the ignition system (preventing shock hazards and damage to ignition components). While these precautions indirectly contribute to accurate readings by preventing other issues, the direct impact on the mechanical compression reading itself is minimal, making 'prevents inaccurate readings' the least significant justification compared to safety and component protection.

What information is required when searching for vehicle details particularly for a customer?

Answer: Make, model and year

When searching for general vehicle details, especially for a customer, the make, model, and year are the most fundamental pieces of information. This combination allows for broad identification of the vehicle, enabling technicians to quickly access relevant service information, parts catalogs, and common diagnostic procedures. While the VIN provides the most specific details, make, model, and year are the primary identifiers for initial inquiries.

What is the MOST probable explanation for a customer's complaint regarding a broken transmission case, rear extension housing mating surface, or center adapter plate?

Answer: Oil leak

A broken transmission case, rear extension housing mating surface, or center adapter plate creates a physical breach in the transmission's sealed housing. This damage directly compromises the integrity of the fluid containment, making an oil leak the most immediate and probable complaint. While severe damage could eventually lead to operational issues, the primary and most direct consequence of such physical damage is fluid loss.

The surface of the cylinder head has been machined. What work is required on the valve train?

Answer: Grind the valve stems

When a cylinder head is machined, material is removed from its mating surface, effectively shortening the distance between the camshaft (or rocker arm pivot) and the valve seat. To compensate for this reduction and maintain proper valve train geometry and valve lash, the valve stems often need to be ground shorter. This ensures the valves close fully and prevents them from being held open or having excessive preload.