Innova 3100 Owner's Manual page 41

1. Oxygen Sensor Monitor
2. Oxygen Sensor Heater Monitor
3. Catalyst Monitor
4. Heated Catalyst Monitor
5. EGR System Monitor
6. EVAP System Monitor
7. Secondary Air System Monitor
8. Air Conditioning (A/C) Monitor
The following provides a brief explanation of the function of each
Monitor:
Comprehensive Component Monitor (CCM) - This Monitor
continuously checks all inputs and outputs from sensors,
actuators, switches and other devices that provide a signal to the
computer. The Monitor checks for shorts, opens, out of range
value, functionality and "rationality."
Rationality: Each input signal is compared against all
other inputs and against information in the computer's
memory to see if it makes sense under the current
operating conditions. Example: The signal from the
throttle position sensor indicates the vehicle is in a wide-
open throttle condition, but the vehicle is really at idle,
and the idle condition is confirmed by the signals from all
other sensors. Based on the input data, the computer
determines that the signal from the throttle position
sensor is not rational (does not make sense when
compared to the other inputs). In this case, the signal
would fail the rationality test.
The CCM may be either a "One-Trip" or a "Two-Trip" Monitor,
depending on the component.
Fuel System Monitor - This Monitor uses a Fuel System
Correction program, called Fuel Trim, inside the on-board
computer. Fuel Trim is a set of positive and negative values that
represent adding or subtracting fuel from the engine. This program
is used to correct for a lean (too much air/not enough fuel) or rich
(too much fuel/not enough air) air-fuel mixture. The program is
designed to add or subtract fuel, as needed, up to a certain
percent. If the correction needed is too large and exceeds the time
and percent allowed by the program, a fault is indicated by the
computer.
The Fuel System Monitor may be a "One-Trip" or "Two-Trip"
Monitor, depending on the severity of the problem.
OBD 2
Learning More
OBD 2 MONITORS
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