| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 2.99 |
| Score | 0% | 60% |
Another name for the powertrain control module is the __________ control unit.
engine |
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transmission |
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universal |
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electrical |
The main computer or powertrain control module (PCM) uses pre-programmed software to analyze the input received from sensors and produce output signals to adjust vehicle performance and operation. (Engine control unit (ECU) is another name for the PCM.)
The right front wheel of your front-wheel drive car drops into a pothole and the left front wheel doesn't lose contact with the road. Which of the following is true?
your car has an independent front suspension |
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your car has an independent rear suspension |
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your car has a rigid axle rear suspension |
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your car has a rigid axle front suspension |
An independent suspension allows the wheels on either side of an axle to move independently from each other. The fact that the left front wheel didn't move up in response to the right front wheel moving down is evidence of this.
Which of the following is not an advantage that disc brakes have over drum brakes?
provide a larger contact area |
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are more easily cooled |
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provide more braking force |
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use less brake fluid |
Brakes utlize friction to slow vehicle tires. Drum brakes employ a cast iron drum that roates with the vehicle axle. When hydraulic pressure is applied to the brake assemblies at the wheels, internal pistons expand and push brake shoes outward into contact with the brake drum slowing the rotation of the axle. More powerful disc brakes operate by pinching a rotating disc betweeen two brake pads and allow for a larger surface area to contact the disc, provide more force, and are more easily cooled.
Which of the following is not a function of antifreeze?
keeps water from freezing at low temperatures |
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raises the boiling point of water |
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aids heat transfer |
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lubricates the cooling system |
Modern car engines are cooled by liquid which circulates through the engine block and cylinder heads absorbing excess heat. This liquid is made up of half water and half antifreeze (commonly, ethylene glycol) which both keeps the water from freezing at low temperatures and raises its boiling point making heat transfer more efficient.
Which of the following is a common firing order for four-cylinder engines?
1-3-4-2 |
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3-1-2-4 |
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1-2-3-4 |
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4-3-2-1 |
The stroke cycle of an engine is governed by the crankshaft which serves to regulate the firing order of the cylinders. All cylinders are not on the same stroke at the same time and correct firing order is important to balance engine operation and minimize vibrations. A common firing order for four-cylinder engines is 1-3-4-2 which indicates that cylinders 1 and 3 fire (power stroke)together and cylinders 4 and 2 fire together.