Actron CP9087 - Manual (Page 50)

2-42
Testing Sensors
Section 2
TEST PREPARATION:
All Air Flow Meter Sensor Tests
IMPORTANT:
• Test all hook-ups shown for the sensor.
• The letter next to the hook-up refers to the test procedure for that hook-up.
• Each hook-up should test O.K. Exception: If two hook-ups are marked with
an asterisk (*) only one of the two hook-ups has to test O.K. This is neces-
sary because some sensors look alike, but have different internal connec-
tions.
Sensor may be tested on or off vehicle.
Warning: Observe all safety precautions (see page ii) if testing sensor on
vehicle.
1) Verify ignition key is OFF.
2) Check Tester battery
Refer to page 1-4. Set RANGE switch to POWER OFF when
done.
3) Disconnect wiring harness from sensor - Inspect for
damage.
Some vehicles use a metal snap ring to secure wiring harness
to sensor. Remove this snap ring before disconnecting wiring
harness.
4) Disconnect ductwork from sensor air intake.
This is so you can operate the sensor element for testing.
Refer to vehicle service manual for disassembly procedure.
5) Off-Car testing only: Remove sensor.
6) Test Preparation is complete. Do tests referenced in
hook-up diagrams.
• Test A - Air Flow Meter Sensor (page 2-43)
• Test B - Air Temperature Sensor (page 2-44)
• Test C - Air Flow Meter Position Switch (page 2-45)