Great Wall GW491QE, Руководство по обслуживанию

Страница: 31 / 222

EF.1-13
United฀Electronic฀engine฀management฀system-Analysis฀of฀function฀/principal฀/
failure฀for฀system฀parts฀&components
Measurement Value
Min. Typical Max.
Unit
Working temperature
Performance฀data
M easurem ent V al ue U ni t
S ensi ti v i ty of new sens or agai nst a
5 k H z si gnal
2 6 8 m V /g
L i neari ty w hen w i thin 3 -5 k H z
1 5 % of
5 k H z v al ue
L inearity under a sy ntony 1 5 -3 9 m V /g
C hange w i thi n w hol e li f e ti m e peri od -1 7 %
M ai n sy ntony f requenc y > 2 0 K H z
R esi stanc e > 1 M
C apac i tanc e 1 2 0 0 4 0 0 P F
I m pedanc e
C apac i tanc e of
c abl e
2 8 0 6 0 P F /m
L eak age res is tanc e
resi stanc e betw een tw o output pi ns of
s ens or
4 . 8 1 5 % M
F l uc tuation of sens iti v i ty af f ec ted by
tem perature
-0 .0 6 % m V /g k
(i)Technical฀&characteristic฀parameter
Limit฀data
(e)Symptom:฀start฀with฀difficulty,฀etc.
(f)Cause฀of฀general฀failures artifical฀failure.
(g)Simple฀measurement฀method
after฀disconnection฀of฀joint Have
digital฀multimeter฀adjusted฀to฀the ohm position,฀connect฀two
penswith฀Pin฀1฀&2฀of฀sensor฀respectively;฀And฀the฀rated฀resistance฀when
at฀ 2 shall฀ be฀ 2.5k
5%,฀ others฀ may฀ be฀ measured฀ from฀ the
characteristiccurve฀shown฀above.฀A฀simulation฀method฀may฀be฀applied
during฀measurement,฀฀details฀as฀shown฀below:฀have฀the฀working฀zone
of฀sensor฀submerged฀into฀฀boiled฀water ensure฀the฀submerge฀is฀with
sufficient฀time ,฀then฀observe฀the฀change฀of฀sensor฀resistance,฀and
the฀resistance฀shall฀be฀decreased฀to฀an฀extent฀within฀300
-400
Specific฀ value฀ depends฀ on฀ the฀ temperature฀ of฀ boiled฀ water .
(h)฀Technical฀&characteristic฀parameter:
Limit฀data
Measuremen
R ated voltage
Rated resistance when at 20
Scope of operation temperature
ured Max. current passing the sensor
llowable vibration acceleration
Structure฀diagram
Connector
2.Shell
3.NTC฀resistor
(a)Function: this sensor is used to provide engine cooling-fluid
temperature information so that a modifcation to oil injection and
ignition may be performed by controller.
(b)Principal
：
This sensor is materially a thermal resistor having
negativetemperature coefficient
（
NTC
）
, its resistance value will
be decreased.
while the temperature is rising, but does not show a linear correlation.
Thethermal resistor is installed in one copper heat condution sleeve.
(c)Installation position
：
on the water oulet mouth of engine.
(d)Mounting torque: 20 N·M
（
Max
）
5. Cooling-fluid temperature sensor TF-W
ProCarManuals.com