AT 261 Final Exam - Spring 2012ALL ANSWERS MUST BE ON THE ANSWER KEY!
Name: ______
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Which term describes the process of manually adjusting variables such as speed, load, and spark timing to determine the optimum output settings for the computer?
A) Performance programming
B) Signal conditioning
C) Engine mapping
D) Reflashing
2) Which of the following components provides the engine control computer with engine coolant temperature information?
A) Engine coolant temperature sensor
B) Manifold absolute pressure sensor
C) Oil pressure sensor
D) Throttle position sensor
3) A typical TP sensor registers how many volts at WOT (wide open throttle?
A) 0.5
B) 4.5
C) 13-15
D) 1.3-3.0
4) Technician A says that other temperature sensors that operate like the ECT (engine coolant temperature) include transmission fluid temperature (TFT), and engine oil temperature. Technician B says that all temperature sensors increase in resistance as the temperature decreases. Which technician is correct?
A) Technician A
B) Technician B
C) Both Technicians A and B
D) Neither Technician A nor B
5) Technician A says that the 3 wires on the TP sensor include a 5-volt reference voltage from PCM, plus the signal wire to PCM, and ground. Technician B says that the TP sensor is used by the PCM to determine torque converter engagement and transmission shift points. Which technician is correct?
A) Technician A
B) Technician B
C) Both Technicians A and B
D) Neither Technician A nor B
6) An engine surges intermittently when driven at cruise speeds. All on it's own it seems to go a little faster, then a little slower, then a little faster again. And the customer says his fuel economy isn't as good as it used to be. The scan tool data was taken at cruising speed as it surged. What is wrong?
Time Frame / -8 / -7 / -6 / -5 / -4 / -3 / -2 / -1 / 0TPS: (v) / 2.4 / 2.4 / 2.4 / 2.4 / 2.4 / 2.4 / 2.4 / 2.4 / 2.4
MAP: (v) / 2.6 / 2.6 / 2.6 / 2.6 / 2.6 / 2.6 / 2.6 / 2.6 / 2.6
ECT: (v) / 0.5 / 0.5 / 3.2 / 3.4 / 0.5 / 0.5 / 0.5 / 0.5 / 0.5
O2: (v) / 0.6 / 0.2 / 0.9 / 1.0 / 0.7 / 0.3 / 0.7 / 0.1 / 0.8
RPM: / 2300 / 2300 / 2400 / 2450 / 2350 / 2300 / 2300 / 2300 / 2300
A) Intermittent injector.
B) TPS intermittent.
C) Timing belt jumped a tooth.
D) Corroded connection at ECT
7) Which computer function describes how the computer handles inputs?
A) Process B) Input C) Output D) Storage
8) Technician A says that all temperature sensors decrease in resistance as the temperature increases. This is called positive temperature coefficient (PTC). Technician B says that some vehicle manufacturers use a stepped ECT circuit inside the PCM to broaden the accuracy of the sensor. Which technician is correct?
A) Technician A
B) Technician B
C) Both Technicians A and B
D) Neither Technician A nor B
9) Technician A says that the ECT and IAT sensors can be tested visually, as well as by using a digital multimeter or a scan tool. Technician B says that the ECT sensor is a high-authority sensor at engine startup and is used for open-loop control, as well as idle speed. Which technician is correct?
A) Technician A
B) Technician B
C) Both Technicians A and B
D) Neither Technician A nor B
10) A ______is a variable-resistance sensor with three terminals.
A) Thyristor
B) Thermistor
C) Rheostat
D) Potentiometer
11) A large amount of oxygen in the exhaust system causes the O2S (Oxygen sensor) to produce which of these?
A) Abnormal readings
B) High voltage
C) Low voltage
D) False readings
12) Most TP sensors have how many wires?
A) 3
B) 2
C) 4
D) 1
13) An IAT is being tested. After the vehicle has been allowed to cool for several hours, a scan tool is used to observe the IAT sensor reading. When compared to the engine coolant temperature (ECT), the two temperatures should be within how many degrees F of each other:
A) 5 – 10
B) 10 -20
C) 25 -50
D) They should never be near equal to each other
14) Technician A says that the 3 wires on the TP sensor include a 5-volt reference voltage from the PCM Technician B says that a TP sensor is a three-wire variable resistor called a rheostat. Which technician is correct?
A) Technician A
B) Technician B
C) Both Technicians A and B
D) Neither Technician A nor B
15) What does the post, or downstream (B1S2) oxygen sensor (HO2S) measure?
A) Amount of H2O behind the catalytic converter
B) Amount of oxygen in front of the catalytic converter
C) Amount of oxygen behind the catalytic converter
D) Amount of H2O in front of the catalytic converter
16) B1S1 - O2 sensors should switch rich to lean, how often?
A) Every 128-136 seconds
B) 8-10 times @ 2000 RPM
C) 10 times in 10 seconds
D) Once per hour
17) Which of these components lets the PCM know how fast you want to accelerate?
A) Idle air control valve
B) Throttle Position (TP) Sensor
C) O2S (Oxygen Sensor)
D) CKP (Crankshaft Position) Sensor
18) With the vehicle in closed loop, the following post converter B1S2- HO2S scope pattern activity is seen. What does this indicate?
A) A missing converter
B) A lazy converter
C) A bad converter
D) A good converter
19) When the concentration of oxygen on the exhaust side of the O2 sensor is low (rich exhaust), a voltage of ______is generated between the electrodes.
A) 0.25-0.50
B) 10-20
C) 1.0-2.0
D) 0.60-1.0
20) Which of the following is a three-wire variable sensor?
A) Rheostat
B) Potentiometer
C) Thermistor
D) Coolant temperature sensor (CTS)
21) Analog signals from sensors are changed to digital signals for processing by the computer through which type of circuit?
A) Analog
B) Digital
C) PROM
D) AD converter
22) Which of these sensors could be used to check for a poor PCM ground?
A) IAT
B) Oxygen (O2S) Sensor
C) ECT
D) TP
23) With the vehicle in closed loop, the following post converter B1S2 - HO2S scope pattern activity is seen. What does this indicate?)
A) A good converter
B) A lazy converter
C) A bad converter
D) None of these
24) With the TP sensor in the position shown, what voltage would be expected at the signal wire (C)?
A) 5.0 volts
B) 0.5 volts
C) 2.5 volts
D) Not enough information
25) Technician A says that oxygen sensors can have one, two, three, four, or more wires, depending on the style and design. Technician B says if the exhaust has little oxygen, the voltage of the oxygen sensor will be close to 1 volt (1000 mV) and close to zero if there is high oxygen content in the exhaust. Which technician is correct?
A) Technician A
B) Technician B
C) Both Technicians A and B
D) Neither Technician A nor B
26) The name for the sensor that measures the temperature of the air being drawn into the engine is called which of these?
A) Intake air temperature sensor (IAT)
B) Negatron temperature coefficient (NTC) thermistor
C) Proactive temperature coefficient (PTC) thermistor
D) Both A and B
27) Which computer function is defined as a voltage signal from a sensor or switch?
A) Input
B) Output
C) Storage
D) Process
28) Which sensor is used to determine engine load?
A) TP
B) MAP
C) ECT
D) RPM
29) Some CAN systems use pin number ______and ______in the DLC to communicate with the scan tool.
A) 4, 5
B) 5, 16
C) 6, 14
D) 4, 16
30) Technician A says that the TP sensor signal voltage should be about 0.5 volt at idle and increase to about 2.5 volts at wide-open throttle (WOT). Technician B says that a TP sensor can be tested using a DMM (digital multimeter), DSO (digital storage oscilloscope), or scan tool. Which technician is correct?
A) Technician A
B) Technician B
C) Both Technicians A and B
D) Neither Technician A nor B
31. The check engine lamp is on - Do all EXCEPT
A. Get the codes - write them down - Clear them - Re run self-test(s)
B. Do a visual inspection of all fuel, air, and ignition components
C. Check for loose vacuum lines, or intake leaks
D. Replace the part that is related to the code without testing it,the scan tool tells you what’s wrong
32. An open ECT or IAT sensor will on most vehicles will;
A. Show a large voltage drop (5 volts) and -40 Deg F.
B. Show a small voltage drop (0.5 volts) and 415 Deg F.
C. Show some voltage drop (2 volts) and 270 Deg F.
D. None of the above
33. A car stalls when at idle. A technician should do all EXCEPT;
A. Check for TSBs
B. Check for intake leaks, vacuum leaks, and trouble codes
C. Unhook the battery to set the idle
D. Inspect the IAC gasket
34. Tech A says that an O2 sensor may set a code from a vacuum leak.Tech B says that a bad 02 sensor could cause high fuel pressure. Whois correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
For the following questions on the next page - Use the ASE L1 Test Guide Engine Schematic
35. The engine cranks, but will not start. Using the scan tool readings above, which one of these is the most likely cause.
A. A short to ground at Pin 1
B. An open circuit at pin 2
C. An open circuit at pin 31
D. A short to ground at pin 32
36.This vehicle has a ______injection system
A. TBI/CFI
B. MPFI
C. MFI
D. SEFI/SFI
37.Tech A says that the IAT and the ECT share the same common ground.Tech B says that ECT and IAT share the same power source. Who iscorrect?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
38.Tech A says that if the wire at pin 45 breaks the car will stall.Tech B says that if the wire at pin 51 breaks the car will stall. Whois correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
39.Technician A says that if the wire breaks at pin 32, the MIL light canstill function because it has a ground. Technician B says that if pin44 breaks, the PCM should set a misfire code for Cylinder number 1.
Who is correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
40.Technician A says that if the wire breaks at pin 57, the vehicle mayrun rich. Technician B says that if pin 21 breaks, the PCM should seta misfire code for Cylinder number 1. Who is correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
41.Technician A says that if fuse number 10 blows, the O2 sensor heaterswill not function. Technician B says that if fuse number 12 blows,the car may overheat and the A/C would not function. Who is correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
42.Technician A says that if fuse number 13 blows, the plugs would notfire. Technician B says the PCM controls the power to the ignitioncoils. Who is correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
43.Technician A says that if fuse number 13 blows, the injectors wouldnot open. Technician B says the PCM controls the ground of the fuelinjectors. Who is correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
44.Technician A says that if pin 63 broke the vehicle should set a code for an O2 sensor heater.Technician B says the PCM controls sees the O2 sensor heater as an input. Whois correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
45.Technician A says that if fuse number 13 blows, the fuel pump wouldnot work. Technician B says that if fuse number 12 blows, the fuelpump would not work. Who is correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B
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