Actron CP9087 - Manual (Page 52)

2-44
Testing Sensors
Section 2
TEST B - Air Temperature Sensor
Warning: Observe all safety precautions (see page ii) if testing sensor on
vehicle.
1) Do all Test Preparation steps.
Refer to page 2-42.
2) Connect test leads.
Connect TEST leads according to diagram B in the component
drawing.
3) Verify test clips make good contact and do not touch each other.
Make sure unused clips are not touching anything.
4) Set RANGE switch to HIGH.
5) Set FUNCTION switch to OHMS.
6) Note TEST light position on tester.
If the sensor is good, the light will move downwards as the sensor
heats up.
7) Heat temperature sensor thoroughly.
• The air temperature sensor is located either...
– In a small tube extending into the air intake passage in front of
the closed vane “door” OR
– In its own housing threaded into the side of the air flow meter
assembly.
• Heat sensor using a hair dryer or similar device. DO NOT use a
match or open flame.
8) Observe TEST light position for test results.
Good Sensor - TEST light moved downwards below original position.
(TEST light may go off if sensor is very hot - this is OK.) The TEST
light will move upwards as the sensor cools off. Range of TEST
light movement varies with sensor type and temperature change.
Bad Sensor - TEST light position did not change during test.
9) Test B is complete.
Set RANGE switch to POWER OFF and remove all test leads.
Reconnect sensor to vehicle if all testing is done.
RANGE
HIGH
LOW
POWER OFF
FUNCTION
VOLTS
OHMS
FREQUENCY