Actron CP9175 OBD II AutoScanner - Manual (Page 55)

A-7
MAT:
Manifold Air Temperature sensor. A resistance sensor in the intake
manifold that sends a voltage signal to the PCM indicating the
temperature of the incoming air. The PCM uses this signal for fuel
delivery calculations.
MIL:
Malfunction Indicator Lamp. “Check Engine” or “Service Engine Soon”
light are examples of what a MIL is called. A required on-board
indicator to alert the driver of an emission-related malfunction.
Misfire:
Caused by the air fuel ratio being incorrect.
Monitor:
A test performed by the on-board computer to verify proper operation
of emission related systems or components.
MPFI or MFI:
Multi-Port Fuel Injection. MPFI is a fuel injection system using one (or
more) injector(s) for each cylinder. The injectors mounted in the intake
manifold, and fired in groups rather than individually.
NOx:
Oxides of Nitrogen. The system EGR and Cam Shafts injects exhaust
gases into the intake manifold to reduce these gases at the tailpipe.
O2S:
Oxygen Sensor. Generates a voltage of 0.6 to 1.0 volts when the
exhaust gas is rich (low oxygen content). The voltage changes to 0.4
volts or less when the exhaust gas is lean (high oxygen content). This
sensor only operates after it reaches a temperature of approximately
349ºC (660ºF). O2 sensors are usually found both upstream and
downstream of the catalytic converter. The PCM uses these sensors
to fine tune the air-fuel ratio and to monitor the efficiency of the catalytic
converter. See Bank 1, Bank 2, Sensor 1, Sensor 2.
OBD II:
On-Board Diagnostics, Second Generation. OBD II is a U.S.
Government-mandated standard requiring all cars and light trucks to
have a common data connector, connector location, communication
protocol, DTCs and code definitions. OBD II first appeared on vehicles
in late 1994, and is required to be present on all cars sold in the US
after January 1, 1996.
ODM:
Output Device Monitor.