Knock Sensor (Ks) Function [Mzi-3.5]; Knock Sensor (Ks) Construction/Operation [Mzi-3.5]; Mass Air Flow (Maf) Sensor Function [Mzi-3.5]; Mass Air Flow (Maf) Sensor Construction/Operation [Mzi-3.5] - Mazda CX-9 2007 Service Highlights

KNOCK SENSOR (KS) FUNCTION [MZI-3.5]

• Detects abnormal combustion in the engine.
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KNOCK SENSOR (KS) CONSTRUCTION/OPERATION [MZI-3.5]

• The KS is the sensor on the engine which
converts engine vibration to an electrical signal.
• The PCM uses this signal to determine the
presence of engine knock and to retard spark
timing.
• Two KS have been adopted.
End Of Sie
NG: MASS AIR FLOW SENSOR

MASS AIR FLOW (MAF) SENSOR FUNCTION [MZI-3.5]

• Detects intake air amount (mass airflow amount).
End Of Sie

MASS AIR FLOW (MAF) SENSOR CONSTRUCTION/OPERATION [MZI-3.5]

• Incorporates the IAT sensor.
• The MAF sensor uses a hot wire sensing element
to measure the amount of air entering the engine.
• Air passing over the hot wire causes it to cool.
• This hot wire is maintained at 200°C (392°F)
above the ambient temperature as measured by a
constant cold wire.
• The current required to maintain the temperature
of the hot wire is proportional to the mass air flow.
• The MAF sensor then outputs an analog voltage
signal to the PCM proportional to the intake air
mass.
End Of Sie
NG: CRANKSHAFT POSITION SENSOR

CRANKSHAFT POSITION (CKP) SENSOR FUNCTION [MZI-3.5]

• Detects the pulse wheel rotation pulse as the engine crank angle signal.
End Of Sie
01-40–8
CONTROL SYSTEM [MZI-3.5]
MAF/IAT SENSOR
MAF/IAT SENSOR
HOT WIRE
AIR FLOW
id0140c1174100
id0140c1174200
KS
ac9uun00000142
id0140c1176800
id0140c1176700
COLD WIRE
AIR FLOW
ac9uun00000177
ac9uun00000143
id0140c1177400