Page 300 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

3 Remove MAF and IAT sensor from air cleaner casing.
a IAT sensor inspection
• Set the multimeter in K resistance mode.

• Measure the resistance between sensor terminals while blowing hot air to temperature sensing part.
The resistance value at 20° C 2.21 – 2.609 K Ω
The resistance value at 60°C 0.49 – 0.667 K Ω

Note: The resistance value is shown as example. It may very as per manufactures model.

b MAF sensor Inspection
1 Connect a 12 V Battery and volt meter To MAF& IAT sensor as shown in fig.
2 Check the voltage variation depending upon amount of blown air it should increase. If it is not
increased,Replace MAF &IAT sensor.

TASK 4: Checking of crank shaft position sensor (CKP) (Fig 1)

Fig 1

Note: These sensors are called by so many different names like: Hall effect sensor, CKP sensor,
MP sensor, pickup coil, Magnetic pulse generator, variable reflector and the list goes on with a
few more names. There are two types Three pin type and two pin type. If the car engine fails to
start properly, there may a defect in crank shaft position sensor and cam shaft position sensor.
This sensor measures the crank shaft position and speed. Both the sensor have the control
injection and ignition timing.
1 Locate the sensor. Normally it is located either end of the crank shaft.
CITS : Automotive - Mechanic Diesel - Exercise 16.1
2 Run the engine and set the multi meter in the AC mille volt range.
3 Measure the voltage using the probes.
4 Normal range would be 200mV. Also refer the manufacturer’s manual for the exact readings. It may vary
manufacturer to manufacturer.

5 If not develops any voltage sensor may be opened. Replace it.
While testing the following condition to be satisfied.

6 Ambient temperature should not exceed 50°C.
7 Accelerator pedal should be in idle position. i.e fully closed condition.

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CITS : Automotive - Mechanic Diesel - Exercise 16.3 CITS : Automotive - Mechanic Diesel - Exercise 16.3