Exam 9: Strategies of on Board Diagnostic Continuous Monitors

Technician A says that the fuel system monitor checks and adjusts both short-term and long-term fuel trim. Technician B says the comprehensive component monitor looks for circuit shorts and opens. Who is correct?

A Type B misfire is one that could cause immediate damage to the catalytic converter, and the misfire monitor will cause the MIL to flash.

List the three separate monitors that make up the continuous monitors?

What type of misfire could cause immediate damage to the catalytic converter and will cause the MIL to flash?

Technician A says the fuel system monitor may not be allowed to run if a pending code is stored. Technician B says the comprehensive component monitor will use one-trip or two-trip logic when determining when to set a DTC and illuminate the MIL, depending on the system and the detected fault. Who is correct?

What values are constantly adjusted by the PCM to correct for rich/lean running conditions?

What type of misfire will cause the emissions to rise above 1.5 times the design limits and will cause the misfire monitor to illuminate the MIL steady but not to flash?

How can a diagnostic scan tool be used to aid in performing a drive cycle, and what is a typical pattern for an OBD II drive cycle?

What do rationality tests check for?

The PCM closely monitors the fuel delivery system through the use of the fuel monitor.

Technician A says a random misfire or a multiple cylinder misfire will be recorded as a P0300 code. Technician B says that a MIL that is flashing is an indication of an intermittent emission system failure that is not currently occurring. Who is correct?

Explain what the comprehensive component monitor is.

Technician A says that the engine misfire monitor is a non-continuous monitor. Technician B says that the engine misfire monitor is a continuous monitor. Who is correct?

The continuous monitors consist of three separate monitors.

The comprehensive component monitor begins to run shortly after the vehicle is started.

The continuous monitors are the catalyst efficiency, misfire, and continuous component monitors.

What must the misfire monitor have the ability to do?

When may the fuel system monitor not be allowed to run?

Explain what Type B and Type C misfires are and what the PCM does to react to these types of misfires.

As a result of a misfire, unburned hydrocarbons (HC) are exhausted from the combustion chamber into the exhaust system, where they enter the catalytic converter.