Honda Accord 2008 Manual page 353

07/11/02 09:00:43 61TA0000_110_0034
Fuel and Emissions Systems
System Description (cont'd)
Knock Sensor
The knock control system adjusts the ignition timing to
minimize knock.
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Manifold Absolute Pressure (MAP) Sensor
The MAP sensor converts manifold absolute pressures
into electrical signals to the ECM/PCM.
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O-RING
11-34
Malfunction Indicator Lamp (MIL) Indication (In relation
to Readiness Codes)
The vehicle has certain ''readiness codes'' that are part
of the on-board diagnostics for the emissions systems.
If the vehicle's battery has been disconnected or gone
TERMINAL
dead, if DTCs have been cleared, or if the ECM/PCM has
been reset, these codes are reset. In some states, part
of the emissions testing is to make sure these codes are
set to complete. If all of them are not set to complete,
PIEZO the vehicle may fail the test, or the test cannot be
ELEMENT
finished.
To check if the readiness codes are set to complete,
DIAPHRAGM
turn the ignition switch to ON (II), but do not start the
engine. The MIL will come on for 15 20 seconds. If it
then goes off, the readiness codes are complete. If it
flashes five times, one or more readiness codes are not
complete. To set each code, drive the vehicle or run the
engine as described in the procedures (see page 11-62).
Mass Air Flow (MAF) Sensor/Intake Air Temperature
(IAT) Sensor
The mass air flow (MAF) sensor/intake air temperature
(IAT) sensor contains a hot wire and a thermistor. It is
located in the intake air passage. The resistance of the
hot wire and thermistor changes due to intake air
temperature and air flow. The control circuit in the MAF
sensor controls the current to keep the hot wire at a set
temperature. The current is converted to voltage in the
control circuit, then output to the ECM/PCM.
TERMINAL
−
O-RING
IAT SENSOR
(THERMISTOR)
HOT WIRE
SENSOR
COLD WIRE
SENSOR
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