Fault Messages That Can Occur During Recovery; Other Fault Messages; Faults During The Vacuum Phase; The Vacuum Pump Starts - Bosch ACS 511 Repair Instruction

en 26 | ACS 511 | TROUBLESHOOTING AND ANALYSIS
11.1.3

Fault messages that can occur during recovery

"CYLINDER FULL"
i
Check the weight of the internal refrigerant cylinder
and reduce the quantity of refrigerant in the internal
refrigerant cylinder.
"PRESSURE VALVE TOO HIGH"
1. Valves V1, V2, V3, and V4 must be open.
2. Check contacts for pressure switch (P2).
i
If the pressure is below 16 bar, voltage must be pres-
ent between pin 1 and pin 2, while pin 1 and pin 4
are open.
i
If the pressure is above 16 bar, the contacts between
pin 1 and pin 2 open, while the pin 1 and pin 4 con-
tacts close.
 If the pressure switch (P2) does not work in this
way, replace it.
 If the pressure switch is working correctly, check
the wiring and the control PCB.
i
If no fault can be identified with the pressure switch
(P2), the line to the internal refrigerant cylinder
must be checked for clogging and the valve VU2 for
clear passage.
11.1.4

Other fault messages

Please see chapter 9.2
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11.2

Faults during the vacuum phase

11.2.1

The vacuum pump starts

i
The vacuum pump starts but no vacuum is generated
in the vehicle air conditioning system
1. Disconnect service hoses from vehicle.
2. Open HP and LP valves.
3. Check whether the hose connected to the vacuum
pump is correctly connected at both ends and is not
clogged.
4. Check the oil level in the vacuum pump.
i
The oil level should be in the middle of the sight
glass between the "full" and "empty" marks.
5. Check the pump vacuum output (the pressure must
fall to less than 0.05 mbar within 3 minutes).
6. If a vacuum of less than 0.05 bar is reached:
Check whether voltage is present at EV1 and EV10.
7. Valves EV8 and EV9 must not leak.
8. Check whether EV1 switches
 If voltage is present and EV1 switches, replace the
vacuum pump.
¶
Check the pump vacuum output (the pressure must
fall to less than 0.05 mbar within 3 minutes).
11.2.2

The vacuum pump does not start

1. Check the oil level in the vacuum pump.
2. Check whether the vacuum pump is turned on (on/
off switch on the rear of the vacuum pump).
3. Check fuses F 2 and F 3 (12.5 A) on the control PCB.
4. Check whether the relay trips after pressing the
vacuum key.
5. Check whether the vacuum pump is being supplied
with power (230 Volt).
i
A voltage of 12 Volt (DC) must be present at the
pump relay coil; 230 Volt must be present at the out-
put contacts. If one of these voltages is not present,
the computer PCB must be replaced.
"
Replace the vacuum pump if it does not start.
Robert Bosch GmbH