ACS 553, ACS 563 Service Manual
1 689 975 295
2021-04-13
Robert Bosch GmbH
43
Diagnostics and Testing
Will Not Air Purge
1. Verify the air purge solenoid (S6) 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
tank pressure are functioning properly.
2. Verify temperature sensor is 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 and air purge solenoid
(S6) for debris.
•
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 Tank pressure, perform the
following:
• Open service menu and go into
Output
test
to enable the tank liquid
solenoid (S7) and LS inlet solenoid (S4).
• Compare the low-side transducer read-
ing shown in the tool bar (enable “display
title info” in maintenance menu) with the
reading on the low-side panel gauge. The
readings should match, assuming the
low-side panel gauge is accurate.
Will Not Evacuate (Vacuum)
NOTE:
The vacuum pump should be running
during this test. If the pump does not run,
refer to
Vacuum Pump Troubleshooting
in the
Vacuum Pump section of this manual.
1. Verify the service hoses are properly
attached to the unit (valves open) without
any restrictions.
2. Make sure the one plastic vacuum line
is snug at both ends and not obstructed.
Check the pneumatic fittings for leaks.
3. Check for proper vacuum oil level in the
vacuum pump sight glass (oil level should
be in the center of the sight glass while the
pump is running). Replace vacuum pump
oil if necessary.
4. Check for suction at the intake of the pump.
If there is none, replace the pump.
5. Verify the vacuum solenoid (S9) is receiving
power and that the low-side (S4) and
high-side (S5) inlet solenoids are open.
• If not receiving power, check continuity
of the wiring between the solenoids and
power board. Repair as needed.
• If the wiring is correct and no power is
being applied to the solenoid, replace the
power board.
6. Check the Oil inject solenoid (S14) for bleed-
through and proper operation. This can be
done by checking for suction at the oil inject
tube in the oil inject bottle. Remove the
oil inject bottle during the vacuum process
and check for suction at oil inject tube or
watch for oil movement in the tube towards
the manifold. Repair as needed.
7. Verify the low-side pressure transducer is
functioning properly.
