SIMPLIFIED TEST EQUIPMENT FOR INTERNAL COMBUSTION ENGINE--REPROGRAMMABLE (STE/ICE-R) TROUBLESHOOTING INTRODUCTION - continued

TM 9-2320-361-24-1

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SIMPLIFIED TEST EQUIPMENT FOR INTERNAL COMBUSTION ENGINE--REPROGRAMMABLE

(STE/ICE-R) TROUBLESHOOTING INTRODUCTION (Contd)

VTM

The VTM provides a method for technicians to test vehicle electrical and mechanical components.

Readings are either pass/fail indications or digital display in units familiar to the technician (psi, rpm,

volts, ohms, amps, etc.).

The VTM interfaces with the vehicle directly with a transducer or a set of transducers from the

transducer kit. Additional tests can also be done that involve manually probing and/or connecting

transducers to appropriate test points. The VTM can be operated on 12 volts or 24 volts drawn from the

vehicle batteries or from an alternative power source.

The controls and readout display on the VTM are described below and illustrated on the following page.

POWER/DIAGNOSTIC CONNECTOR ASSEMBLY (DCA) CONNECTOR (J1): Connector J1

connects to the battery or the DCA by cable W5 to supply power to the VTM.

TRANSDUCER CABLE CONNECTORS (J2 AND J3): Connectors J2 and J3 connect the VTM

to any transducer in the transducer kit. Operating power is supplied to the transducer, and

signals from the transducer are supplied to the VTM by cable. Connectors J2 and J3 are identical

and can be interchanged with each other or used in combination.

READOUT DISPLAY: The readout display shows different types of readouts during testing

procedures. The readout display has the capability of displaying up to 4 characters (for example

.8.8.8.8).

TEST BUTTON: Pressing and releasing the TEST button causes test measurements to begin.

Observe measured values on the readout display. The reading will be in units normally used in a

particular vehicle measurement. These units are displayed on the test flip-cards. The TEST button

must be pressed and immediately released. Pressing and holding the TEST button initiates an

offset test. Offset tests are described in TM 9-4910-571-12&P.

TEST SELECT SWITCHES: The TEST SELECT switches are used to select the test being

performed. There are ten positions on each switch, numbered 0 through 9. The numbers dialed

into these switches are read by the VTM when the TEST button is pressed. Changing the position

of the switches has no effect until the TEST button is pressed again.

POWER SWITCH (PUSH ON/PULL OFF): The power switch controls DC power to the VTM.

The VTM can operate from either a 12-volt or 24-volt battery system. When the power switch is

pushed in (PUSH ON), VTM power is on. To shut off power to the VTM, pull out the power switch

(PULL OFF). The power switch contains a 4-amp circuit breaker. If a fault occurs and the VTM

uses more power than it should, the power switch will pop out automatically. Check the connection

carefully and try again before returning the VTM to support maintenance.

TEST CARDS: The test cards list the 2-digit test number system for selecting various tests. The

cards also summarize test and operating procedures.

TEST PROBE CABLE CONNECTOR (J4): Connector J4 connects test leads to the VTM when

performing manual voltage and resistance tests.

VTM troubleshooting procedures can be found in STE/ICE-R Go Chain Troubleshooting

(WP 0017 00). Additional VTM troubleshooting can be found in TM 9-4910-571-12&P, Simplified

Test Equipment for Internal Combustion Engines.

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