Exam 2: Computers in Cars

What decimal (base 10) value is represented by the binary code "10110011"?

Which air-fuel ratio would provide the most power?

Technician A says that a PCM uses an output actuator to keep itself informed of engine operating conditions.  Technician B says that a PCM uses an output actuator to cause a change in the performance of a circuit or system. Who is correct?

W hich of the following is NOT required in order for an engine computer to enter closed loop operation?

Which gas is naturally produced within the engine's cylinders through combining the hydrogen atom of the HC molecule with atmospheric oxygen?

Which component is a memory type that allows the microprocessor to change the information that is stored in it?

What is indicated if the oxygen sensor voltage is cycling back and forth across the stoichiometric value several times per second?

A vehicle's engine computer does not operate properly.  The vehicle's battery is checked with a DVOM and has an open circuit voltage of 8.3 volts. Technician A says that the PCM is probably defective and should be replaced. Technician B says that, before condemning the PCM, the battery should be charged and retested.  Then the appropriate voltage drop tests of the PCM's power and ground circuits should be performed. Who is correct?

Concerning the logic gate pictured in Figure 3 above, which condition would produce binary "one" for "C" (the output)?

Which designation is NOT one of the three basic logic gates from which all of the more complex gates are built?

In addition to providing voltage to the computer's internal circuits, what is the purpose of the reference voltage regulator within a modern PCM?

Technician A says that closed loop is the most efficient operating mode and allows the engine computer to control the air-fuel ratio with the most precision. Technician B says that open loop operation is used to improve performance during cold engine warm-up and is also used under heavy load or during wide open throttle operation. Who is correct?

Which description defines a computer input?

What is the advantage of controlling the air-fuel ratio to a stoichiometric ratio?

What does a "baud rate" of 41,600 mean?

Exhaust gasses are being discussed. Technician A says nitrogen (N) is considered a harmful gas. Technician B says carbon monoxide (CO) is considered a harmful gas. Who is correct?

Which operating condition(s) has/have the programmed goal of _____ maintaining a stoichiometric air-fuel ratio?

Which component in an engine computer is a volatile memory and stores sensor input values until updated, strategy results, fuel trim data, and memory type fault codes?

A scan tool is displaying the hexadecimal value for the binary code "1010000100111110".  Which hex value is displayed on the scan tool?

"Closed loop" is defined as  a system operating mode: