HUBITOOLS HU31010 Manuel D'instructions page 13

Meter Functions- ms-PULSE (Pulse Width) & ms- PERIOD (Period)
Pulse Width is the length of time an actuator is energized. For example, fuel injectors are activated by an
electronic pulse from the Engine Control Module (ECM).
This pulse generates a magnetic field that pulls the injectors nozzle valve open.
The pulse ends and the injector nozzle is closed.
This open to close time is the Pulse Width and is measured in milliseconds( ms).
The most common automotive application for measuring pulse width is on fuel injectors.
You can also measure the pulse width of the fuel mixture control solenoid and the idle air control motor.
This exercise shows how to measure Pulse Width on Port Fuel injectors.
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To measure pulse width (mS):
Select the "mS-Pulse" function with the rotary switch .
Ω
Press the ±TRIG button for 2 seconds until the negative (-) trigger
slope is displayed on the upper left side of the display.
Ω
NOTE : The applied time for most fuel injectors is displayed on the
negative (-) slope.
Insert:
Black lead in COM jack.
Red lead in V-Ω -RPM jack.
Connect:
Jumper wires between the fuel injector and the harness connector.
Black test probe to a good ground at the fuel injector or the negative (-)
vehicle battery post.
Red test probe to the fuel injector solenoid driver input on the jumper cable.
Start the engine. A pulse width in milliseconds should be read.
Note: Initially, the unit will read "OL", then readings will descend and
stabilize to the actual pulse width. If "OL" remains, re-check your
connections.
Meter Functions-RPM/×10RPM