ACS 653, ACS 663 Service Manual
SP00D00624
2021-04-08
Robert Bosch GmbH
54
Diagnostics and Testing
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 two plastic vacuum lines
are 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 PAG (S2), POE (S14) and dye
(S15) solenoids for bleed-through and
proper operation. This can be done by
checking for suction at the oil/dye inject
tube in the oil/dye inject bottle. Remove the
oil/dye inject bottle during the vacuum
process and check for suction at oil/dye
inject tube or watch for oil/dye movement
in the tube towards the manifold. Repair as
needed.
7. Verify the low-side pressure transducer is
functioning properly.
Vacuum Pump Not Running
1. Check gauges for vacuum.
2. If pressure is over 690 mBar (10 psi), clear
hoses. If unit won’t maintain vacuum, check
the following for leakage:
• High-side charge solenoid (S6) and low-
side charge solenoid (S7).
• Hose couplers.
• Hoses.
• Gauge tubing.
• Injection manifold.
• Suction side vacuum hoses and
connections.
3. If there is no pressure on gauges and
display says Pressure Exists, enter the
service menu and verify low-side inlet
transducer reading. If it is reading pressure
where none exists, replace transducer.
If replacing the transducer doesn’t correct
the reading, replace the power board.
4. Refer to
Vacuum Pump Does Not Run
in
electrical troubleshooting.