Tester Basics; Description Of Controls And Accessories; Installing And Checking The 9 Volt Battery; Range Switch, Function Switch - Actron CP9087 Service Manual

Section
1

— Description of Controls and Accessories

— Installing and Checking the 9 Volt Battery

Note: Detailed procedures for testing sensors and ignition modules are
located in Section 2 (sensors) and Section 3 (ignition modules).
RANGE
Switch
FUNCTION
Switch
Tester
Basics
1
Controls power to the Tester and selects measure-
ment range sensitivity (as required by various
sensor tests).
• POWER OFF - No power supplied to either the
tester or RED test lead.
• LOW - Tester powered up for use. Voltage from
9 volt battery supplied to RED test lead. Selects
range for measuring low levels of voltage,
resistance or frequency.
• HIGH - Tester powered up for use. Voltage from
9 volt battery supplied to RED test lead. Selects
range for measuring higher levels of voltage,
resistance or frequency.
2
Selects the type of signal being measured (for
conducting sensor and ignition module tests). Different
kinds of signals are used by various sensors.
• VOLTS - Measures voltages. This function is used
to test most sensors.
• OHMS - Measures resistance. Also used for
checking continuity and testing diodes (see section
4). Mostly used for testing temperature sensors.
• FREQUENCY - Measures frequency signals.
(Peak signal voltage must be at least 3 volts
to register.) Some MAP and MAF sensors
send a frequency signal. This function is
also used to test ignition modules.
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