GM Service Manual Online
For 1990-2009 cars only

Notice: Refer to Test Probe Notice in the Preface section.

The following procedure determines the frequency of a signal.

Important: Connecting the Digital Multimeter to the circuit before pressing the Hz button will allow the Digital Multimeter to autorange to an appropriate range.


    Object Number: 1940102  Size: SH
  1. Turn the switch (4) to the ON position to apply power to the circuit.
  2. Set the rotary dial to the V (AC) (7) position on the Digital Multimeter (1) .
  3. Connect the positive lead of the Digital Multimeter (1) to the circuit to be tested (3).
  4. Connect the negative lead of the Digital Multimeter (1) to a known good ground (5).
  5. Press the Hz button on the Digital Multimeter (6).
  6. The Digital Multimeter will display the frequency measured (2).