Thermo King SR-2 SmartReefer2, Diagnostic Manual

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Section 6 – SR-2 Service Procedure G03A
and 800 indicates the valve is fully opened. Field experience indicates that if the correct signals are present that
the valve will operate. Few mechanical valve problems have occurred.
IMPORTANT: Due to design changes, the ETV test procedure used for uP-VI equipped units can not be used
with SR-2 units. Voltages cannot be measured as they were with uP-VI applications.
Diagnostic Procedure
Step Action Result Comments
1 Be certain that all connectors are
secure.
2 Disconnect the interface board
connector J7 and measure the
resistance from the EVA wire to
the EVB wire at the connector.
J7 Pin 24 – EVA wire
J7 Pin 23 – EVB wire
The resistance should be from
20 to 35 ohms. If the resistance
is incorrect check the EVA and
EVB wires and connectors
leading to the electronic throttling
valve. Also check the EVA and
EVB wires for shorts to ground.
Be sure the valve connector is
properly attached to the valve.
Identify the associated pins
on the ETV and check for
continuity at the valve. If the
resistance from the EVA and
EVB pins directly on the valve
is not from 20 to 35 ohms the
valve is defective. Neither pin
should show a short to
ground.
3 Measure the resistance from the
EVC wire to the EVD wire at the
connector.
J7 Pin 11 – EVC wire
J7 Pin 12 – EVD wire
The resistance should be from
20 to 35 ohms. If the resistance
is incorrect check the EVC and
EVD wires and connectors
leading to the electronic throttling
valve. Also check the EVC and
EVD wires for shorts to ground.
Be sure the valve connector is
properly attached to the valve.
Identify the associated pins
on the ETV and check for
continuity at the valve. If the
resistance from the EVC and
EVD pins directly on the valve
is not from 20 to 35 ohms the
valve is defective. Neither pin
should show a short to
ground.
4 Connect J7 to the interface
board.
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P41RG03A 31 January 2005