Chapter 25: Mindtap
improper converter clutch lockup
A defective IAT sensor or circuit may cause the following problems, except: - hard engine starting - rich or lean air-fuel ratio - improper converter clutch lockup - reduced fuel economy
True
T/F: A bad ground can cause an increase in the reference voltage to a sensor.
False
T/F: An A/F ratio sensor can be tested in the same way as an oxygen sensor.
False
T/F: If a zirconium oxygen sensor's voltage toggles between 0 volts and 500 millivolts, it is operating normally
Tech A
Technician A says that a faulty MAF sensor can cause the engine to run lean. Technician B says that a faulty MAP sensor can cause the engine to not start. Who is correct?
Tech A
Technician A says that an oxygen sensor can be a voltage-producing sensor. Technician B says that an oxygen sensor is a thermistor sensor. Who is correct?
ignition system misfire
The catalyst monitor test may fail for all of these reasons, except: - defective upstream or downstream oxygen sensor circuits - leaking exhaust - fuel contaminants - ignition system misfire
Both
When testing a frequency varying MAF: Technician A says that the frequency should increase with an increase in engine speed. Technician B says that when observed on a lab scope, the signal from the sensor should be a square wave. Who is correct?
faulty ks
Which of the following is the least likely cause of a no-start condition: - Faulty CKP sensor - Faulty KS - Fuel or ignition system faults - Faulty PCM wiring
Both
While diagnosing the cause of a hard starting condition: Technician A checks the ECT sensor. Technician B checks the MAP sensor. Who is correct?
Both
While discussing ECT sensor diagnosis: Technician A says that a defective ECT sensor may cause hard cold engine starting. Technician B says that a defective ECT sensor may cause improper operation of emission control devices. Who is correct?
Tech B
While discussing Hall-effect vehicle speed sensor tests: Technician A says to use an ohmmeter to test the resistance of the coil. Technician B says that the voltage generated by the sensor can be measured by connecting a voltmeter across the sensor's terminals. Who is correct?
Both
While discussing TP sensor diagnosis: Technician A says that a four-wire TP sensor contains an idle switch. Technician B says that in some applications, the TP sensor mounting bolts may be loosened and the TP sensor housing rotated to adjust the voltage signal with the throttle in the idle position. Who is correct?
Tech B
While discussing testing OBD II system components: Technician A says that a testlight can be used to test O2S output. Technician B says that a digital voltmeter can be used to test the O2S. Who is correct?
Neither
While discussing the MIL on OBD II systems: Technician A says that the MIL will flash if the PCM detects a fault in a sensor or circuit. Technician B says that as soon as the PCM has detected a fault, it will turn on the MIL. Who is correct?
Neither
While discussing zirconium O2S diagnosis: Technician A says that the voltage signal on a satisfactory O2S should always be cycling between 0.5 volt and 1 volt. Technician B says that a contaminated O2S may produce a continually high voltage signal. Who is correct?
