Geely FC Workshop Manual page 21

4. Knock sensor (4G18-3600020)
Measuring method:
(Removing the joint) place digital universal meter at ohm gear,
and connect 2 terminals respectively to 1 # pin and 2 # pin, and
the resistance under normal temperature should be more than
1M . Place digital universal meter at millivolt gear, and knock
around knock sensor with a hand hammer, there should be voltage
signal output at the moment.
5. Water temperature sensor (4G18-3600040)
This sensor applies sealing NTC thermal resistor in temperature sensor, and resistance value varies with
ambient temperature, thus slight change of outside temperature could be measured. Measuring its out-
put resistance could reflect the temperature of contact media. Signals from A and C are sent to ECU,
and Signals from B and earth are sent to instrument.
Operating principle (Fig. 1):
Note: A, B and C represent 3 pins of sensor, and see pin root for the mark.
10
Engine control system·- EFI system
1 Vibration block
2 Housing
3 Piezoelectric ce-
ramics
4 Contact
5 Electric connec-
tion
Fig. 1