Will Not Drain Oil; Will Not Air Purge - Bosch ACS 753 Repair Instructions

Diagnostics and Testing

Will Not Drain Oil

1. Verify the accumulator transducer is
functioning properly.
2. Is an Oil Drain Error Message displayed?
• Error 1 - Oil drain halted. Pressure error.
Retry or exit?
a. Verify operation of the compressor oil
return solenoid (S13).
b. C h e c k Ta n k L i q u i d s o l e n o i d ,
evacuating the tank with a recovery
service unit in advance.
c. Verify there is 454 g (1 lb) minimum
chargeable refrigerant in the ISV.
• Error 2 - Oil drain halted. Flow error. Retry
or exit?.
Verify the oil drain solenoid (S3) is
receiving power and opening properly.
a. If not receiving power, check the
continuity of the wiring between
solenoid and power board. Repair
as needed.
b. If the oil drain solenoid is receiving
power and is opening, verify the oil
drain line isn't plugged.
c. If the wiring is correct and no power is
being applied to the solenoid, replace
the power board.
d. If the unit continues to drain oil for four
minutes, Oil Drain Error 2 will display.
The accumulator may be filled with oil
that must be drained manually.
NOTE: Determine the reason the oil separator
isn't draining properly. Improper draining
could be caused by a faulty component or
improper operation by the user. Access the
maintenance counters in the service menu.
Comparing the recover cycles to the oil drain
cycles may indicate user operational errors. If
the procedure, in step a above, does not resolve
the problem, replace the control board.
SP00D00609 2018-03-26
ACS 753, ACS 763, ACS 863 Service Manual

Will Not Air Purge

1. Verify the air purge solenoid (S1) is receiving
power and opening properly.
• If not receiving power, check the
continuity of the wiring between solenoid
and power board. Repair as needed.
• If the wiring is correct and no power is
being applied to the solenoid, replace
the power board.
NOTE: Verify the tank temperature sensor and
pressure transducer are functioning properly.
To verify tank pressure transducer, perform
the following:
• Open service menu and goes into
Output test.
• Open Tank solenoid and high-side
charge solenoid, check the value on
high gauge.
2. Manually purge air.
• Verify air purge transducer and
temperature sensor are reading
correctly.
• The air purge function will time out after
four minutes if the ISV pressure doesn't
reach the calculated pressure within
that time. This may indicate excessive
air in the ISV that must be purged.
3. If the air doesn't purge, check the 0.028-in.
orifice between the ISV pressure transducer
and air purge solenoid (S1) for debris.
• Check Tank Liquid solenoid, evacuating
the tank with a recovery service unit in
advance. If the orifice is contaminated or
defective, repair or replace as needed.
• If the orifice is operating properly,
proceed to the next step.
4. To test the temperature sensor, determine
the ISV temperature and compare it to the
temp probe reading in the air purge info
screen.
5. To verify pressure transducer, perform the
following:
• Open service menu and goes into Output
test to enable the tank liquid solenoid
S22, high-side charge solenoid S6 and
low-side charge solenoid S7.
• Compare the data with the one readable
in input test or in the tool bar (enable
display title info in maintenance menu).
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Robert Bosch GmbH