目录.p65

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.

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.

Engine control system·- EFI system

Fig. 1

1 Vibration block

2 Housing

3 Piezoelectric ce-

ramics

4 Contact

5 Electric connec-

tion

4. Knock sensor (4G18-3600020)

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