Sensors And Transducers; Control Board Software Updating Methods - Bosch ACS 753 Repair Instructions

Electrical

Sensors and Transducers

The sensors and transducers provide the
input and feedback data needed to control the
operation of unit.
Sensors include:
1. Air Flow Sensor (AF): senses whether the
unit cooling fan is operating (present but
disabled on ACS 753).
2. Scale Assembly: weighs the refrigerant
in the ISV as a baseline for determining
the amount of refrigerant withdrawn from
the vehicle A/C system, the amount of
refrigerant added to the system, and how
much refrigerant is available in the ISV for
use.
3. ISV Tank Temperature (TT): supplies the
temperature of the refrigerant stored in
the ISV for adjusting fluid weight based on
density.
4. Ambient Temperature (AMBT): supplies
the base temperature reference for the
refrigerant control.
5. Oil Drain Load Cell: senses the weight of
the oil being drained (separated) from the
vehicle A/C system.
6. PAG or POE Load Cells: senses the
weight of the oil available for use by the
unit servicing the vehicle A/C system and
provides information to the unit as to how
much oil was injected into the vehicle A/C
system.
7. Dye Load Cell: same as PAG or POE Load
Cells, but for dye.
8. Refrigerant Identifier: identifies R1234yf
refrigerant and tests refrigerant for purity
(internal on the ACS 863; external through
the USB port on the ACS 763, function
disabled on ACS 753).
Transducers include:
1. Low-side Pressure (LSP): measures the
pressure in the low side of the vehicle A/C
system.
2. Accumulator Pressure (AP): measures
the pressure in the oil separator to ensure
proper oil separation from the refrigerant.
3. ISV Tank Pressure (TP): measures the
pressure in the ISV tank.
SP00D00609 2018-03-26
ACS 753, ACS 763, ACS 863 Service Manual

Control Board Software Updating Methods

To access the operational capability of the
unit, or to provide an interface to an external
computer (or network), or to update the
software as required occasionally to keep the
unit current. See Firmware update in the Setup
Menu Function section.
Refer to Figure 3-4 (Sheets 1 through 4), for a
graphical representation of the interconnection
of the electrical components.
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Robert Bosch GmbH