Exam 10: Strategies of On-Board Diagnostic Non-Continuous Monitors

Which converters must be monitored by the PCM if a V design engine is equipped with two primary (manifold) catalytic converters and one secondary (downstream) catalytic converter?

The enhanced evaporative emissions system must be capable of detecting a leak as small as 0.020 inch (0.5 mm).

A two-trip DTC will be stored in the PCM memory when a fault is detected during the first trip.

What is indicated to the PCM if the post-oxygen sensor switches from rich to lean frequently?

When is the optimum time for the maximum EGR system flow rate?

The evaporative emissions system monitor will not run if Oxygen Sensor Monitor Failed.

A two-trip DTC will be stored in the PCM memory when a fault is detected during a subsequent second trip, and the MIL will begin flashing.

Downstream secondary air injection systems are only used on conventional oxidation catalyst systems.

The EVAP charcoal canister functions as a storage container for fuel vapors.

During the diagnostic test procedure for a Catalyst Efficiency code, a diagnostic scan tool is connected to the DLC with the vehicle at operating temperature, and the data screen displays the pre-catalyst oxygen sensor continually switching between 200 mV - 800 mV, while the post-catalyst oxygen sensor's output voltage stays relatively steady at 700 mV. Technician A says that the post-catalyst oxygen sensor is fixed rich and should be replaced. Technician B says that the oxygen sensor readings are both normal. Who is correct?

The evaporative emission system is designed to reduce which pollutant?

Technician A says the heated oxygen sensor monitor performs two distinct tests; one test verifies the performance of the pre- and post-oxygen sensor heater element and circuit. Technician B says the heated oxygen sensor monitor performs two distinct tests; one test monitors the pre- and post-oxygen sensor signal switch rate and signal circuit. Who is correct?

Explain the function of the evaporative emissions system monitor.

The thermostat monitor was integrated into OBD II systems beginning in what year?

Technician A says that a dirty air filter can affect short-term fuel trim. Technician B says that a dirty air filter can affect long-term fuel trim. Who is correct?

What are the two distinct tests that the heated oxygen sensor monitor performs?

Explain the function of the exhaust gas recirculation system monitor.

Explain the purpose of the catalyst efficiency monitor.

Technician A says the catalyst's ability to store and release oxygen is a direct indication of the catalyst's performance. Technician B says the catalyst monitor compares the signal from both the upstream and downstream oxygen sensors. Who is correct?

The enhanced system must be capable of detecting a leak as small as 0.060 inch (1.5 mm).