Great Wall GW491QE, Руководство по обслуживанию

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EF.2-13
Delphi฀engine฀management฀systm-Determination฀on฀the
principal฀/utility฀/failure฀of฀key฀system฀parts
7.฀฀Coolant฀temperature฀sensor฀(CTS)
Sensor
(a)Function฀&principal
-The฀coolant฀temperature฀sensor฀is฀used฀to฀check฀the฀working฀temperature
of฀engine Depending฀on฀various฀temperatures,฀ECM฀will฀provide฀the
engine฀with฀an฀optimum฀control฀scheme.฀And฀the฀coolant฀temperature
sensor฀adopts฀thermal฀resistor฀with฀negative฀temperature฀coefficient฀as
induction฀component
-Wiring฀terminal A-signal฀ground,฀B-฀temperature฀signal
-Installation The฀coolant฀temperature฀sensor฀shall฀be฀installed฀on฀a
coolant฀minor฀cycle฀passage฀of฀engine.
(b)Failure฀determination
Important฀note Either฀of฀following฀determinations฀may฀be฀concluded
based฀on฀that฀the฀whole฀vehicle,฀its฀wire-harness,฀and฀other฀system฀parts
&components฀are฀normal฀in฀function.
-The฀temperature฀value฀read฀from฀a฀Diagnosis฀Instrument฀shall฀be฀consistent
to฀the฀actual฀value
-฀The฀temperature฀value฀has฀a฀large฀deviation
-At฀normal฀temperature฀(20฀~฀30)
its฀resistance฀value฀is฀(3510฀~
2240) .
(c)Characteristics฀of฀product
- Working฀voltage 5 V฀ DC
฀฀฀-Working฀temperature฀ (-40 135)
฀฀฀฀ 8.฀Oxygen฀sensor฀(O
2
)
(a)Function฀&principal
-The฀oxygen฀sensor฀is฀regarded฀as฀a฀significant฀component฀within฀the
closed-loop฀fuel฀control฀system,฀usable฀to฀adjust฀or฀retain฀an฀ideal฀air฀/fuel
ratio,฀so฀that฀the฀three-way฀catalytic฀converter฀could฀reach฀an฀optimum
conversion฀efficiency.฀When฀the฀air฀/fuel฀ratio฀involved฀in฀engine฀combustion
becomes฀thin,฀the฀accumulative฀oxygen฀content฀in฀exhaust฀gas฀will฀be
increased,฀while฀the฀output฀voltage฀of฀oxygen฀sensor฀will฀be฀decreased;
On฀the฀contrary,฀the฀output฀voltage฀value฀will฀be฀increased.฀In฀such฀way,
information฀concerning฀the฀air฀/fuel฀ratio฀may฀be฀feedbacked฀to฀ECM.฀The
main฀sensitive฀material฀of฀oxygen฀sensor฀is฀zirconia.฀When฀zirconia฀is
activated฀by฀the฀heat฀exhaust฀gas฀(300 ),฀the฀oxygen฀ion฀will฀pass฀through
the฀zirconia฀component,฀and฀reach฀its฀outside฀electrode.฀The฀zirconia
component฀will฀induce฀the฀oxygen฀content฀in฀exhausted฀gas฀from฀engine,
and฀change฀its฀output฀voltage฀value.฀The฀oxygen฀sensor฀is฀made฀from
shaped฀stainless-steel฀component฀and฀Teflon฀insulation฀lead฀wire;฀And
the฀reference฀air฀is฀input฀from฀lead฀wire;
-Wiring฀terminal฀ A-signal฀low,฀B-signal฀high C฀and฀D-฀connect฀to฀a
heat฀power฀supply
-Installation The฀oxygen฀sensor฀shall฀be฀installed฀between฀the฀exhaust
valve฀and฀the฀three-way฀catalytic฀converter.
฀฀฀฀฀฀฀(b)Failure฀determination
Important฀note E ither฀of฀following฀determinations฀may฀be฀concluded
฀฀฀฀฀฀based฀on฀that฀the฀whole฀vehicle,฀its฀wire-harness,฀and฀other฀system฀parts
฀฀฀฀฀฀& components฀are฀normal฀in฀function.
-The฀voltage฀value฀of฀oxygen฀sensor฀may฀be฀read฀out฀from฀a฀Diagnosis
฀฀฀฀฀Instrument;฀when฀not฀on฀ground,฀non-heat฀type
-T he฀voltage฀is฀450mV ;฀Heat-type the฀voltage฀is฀less฀than฀450mV
-T he฀thick-thin฀abrupt฀change฀time฀is฀too฀small;฀Heavy฀metal฀(eg. lead,
฀฀฀฀฀฀manganese,฀etc.),฀phosphorus฀and฀sulphur฀poison,฀or฀damaged฀due฀to฀high
฀฀฀฀฀฀temperature.
฀฀฀฀฀(c)฀Characteristics฀of฀product
-Working฀temperature฀ (260 850)
-Max.฀over-heat฀temperature฀ ฀930
-Heating฀resistance(23 )฀ 13
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