ASE Practice Test #4
With an electronically controlled automatic transmission, the line pressure test displays low pressure when the gearbox is idle in all gear ranges. What could be the reason?
Explanation:
The oil pump or pressure regulator could produce low pressure while idling in all gear ranges. The maladjusted TPS would only cause high line pressure at idle whereas an open in dropping resistor circuit only generates high line pressure as well. The ATF temperature would likewise only produce high line pressure at idle.
An engine starts to knock, and the sound varies with the RPM. The noise goes away when the cylinder is examined during a balance test. What is the most probable reason?
Explanation:
The most likely cause is a damaged rod bearing. When the RPM changes, it makes a knocking noise. When the cylinder is shorted out, it then fully vanishes.
According to Technician A, when the condenser airflow is constrained, both the high and low lines are experiencing high pressure. According to technician B, low pressure on both the high and low sides is frequently a sign of low refrigerant. Who is accurate?
Explanation:
Both of these technicians have the right responses. It may mean that the condenser airflow has been restricted if there is high pressure in both lines. Low pressure on both sides may also be a sign of low refrigerant.
Which of these steps would you want to complete last when using a diagnostic method to check into a drivability issue?
Explanation:
Make sure the repair was finished after you've finished it. The process comes to an end with this phase. Prior to this, all other procedures should be completed.
According to Technician A, the length of the spark line, which is dependent on the coil voltage and total primary circuit resistance, depends on the voltage needed to keep the spark. According to technician B, issues with the burning manifest themselves within the spark line.
Explanation:
Problems with fuel or air burning are called fuel propagation. It shows up within the sparkline. Technician A is inaccurate because the duration of the thesparklinee is dependent on the overall secondary circuit resistance and coil voltage available. The DI system's usual firing voltage is 8-10 kv with the normal current flow that lasts 1.2-2 milliseconds.
Refrigerant must be added to: in order to charge the air conditioning system while it is operating.
Explanation:
Only on the low side should refrigerant be supplied while the engine is running. All of these solutions are inappropriate to carry out while the engine is running. Refrigerant addition to the high pressure side of the A/C system would be risky.
At higher speeds than specified, shifting in an automatic transaxle starts to happen. ALL OF THESE, WITH THE EXCEPTION OF:
Explanation:
Shifting occurs at lower speeds due to excessive governor strain. A no-shifting state is brought on by stuck governors. Any speed will have inconsistent shifting due to worn governor weights or springs.
The heater is not blowing warm air, according to a consumer who enters the store. When activated, it blows frigid air. Although the temperature never rises, all fan speed settings are functional. Which of the subsequent problems is most likely to be at fault?
The correct answer:
A restricted heater core
Which of these methods is not permitted for obtaining DTC?
Explanation:
The fault alert bulb should not be turned on and off repeatedly. Specifications and setup instructions are printed on the underhood label of automobiles with changeable timing. The other three options are suitable strategies.
What is the MOST likely explanation if the transmission can change into two gears at once?
Explanation:
The interlock is responsible for protecting you from participating in more than one gear at a time. When this is broken, it's possible for the transmission to shift into two gears at once. A damaged input bearing, worn countershaft bearing, and worn speed gears would not cause this problem.
You are running a cylinder compression test and got a zero compression reading plus severe engine blowby. This indicates which of the following?
Explanation:
There are a number of indications that a piston hole will produce. Engine noises like rattling or knocking during idle are frequently caused by piston failure. Additionally, it could result in oil burning, power loss, and misfiring.