Actron CP9087 - Manual (Page 51)

Mass Air Flow MAF
2-43
TEST A - Air Flow Meter 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 A in the
component drawing.
• Important: If two hook-ups are marked with an asterisk
(*) only one of the two hook-ups has to test O.K. This is
necessary because some sensors look alike, but have
different internal connections.
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 VOLTS.
6) Operate sensor - Watch TEST light for results.
Slowly move the sensor element (pivoting “door” or sliding
cone) back and forth from fully closed to fully open
position. Use a pencil, or similar object, to push on the
“door”. This will not harm the sensor.
Good Sensor - TEST light smoothly moves up or down as
sensor is operated. (The TEST light may go off if it moves
to the bottom of the column - this is O.K.) Range of TEST
light movement varies with sensor type.
Bad Sensor - TEST light position does not change during
test OR light movement is erratic, showing a sudden jump
or dip during smooth sensor operation.
7) Test A 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