Chery A11 2003 Repair Manual page 233

Fig. 147 absolute pressure sensor
ignition switch is switched on, the actual atmospheric pressure may be obtained by this method.
When engine is running, the vacuum will produce a mechanical effect on the ceramic membrane of the
sensor resulting in the change of resistance.
Fig.148 sensor output
5 ignition advance calculation and high voltage distribution
The system uses two high tension ignition coils and assigns ignition voltages directly to spark plugs by
static electricity (distributorless ignition) directly. Connector and controlling triode are comprised in the ECU
injection system and connected to ECU connector 1 and connector 19 . (figure. 149).
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CAC Gasoline Engine Maintenance And Servicing Manual
3-way connector ( figure. 147)
a. supply 5V voltage
b. negative pole signal
c. positive pole signal
When engine is shut down, the sensitive membrane will bent
according to the value of atmospheric pressure (mmHg). After the
for ECU supplies a absolutely constant 5V voltage , the
change of output voltage caused by the change of resistance is
indicated in figure. 148.
Sensor supplies the most important data to ECU for
calculating the intake air volume. When the pressure signal is P
＜97mmHg or P＞783mm Hg，if the throttle valve position
sensor doesn't fail, the operation comeback will be performed
according to the throttle valve angle and speed value stored in the
calibration scale. If throttle valve fails, only one comeback
value may be applied—— about 442mmHg.
Note: If absolute pressure sensor needed to be
replaced, the connecting pipe must have the same
diameter and length as the original pipe.
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