Komatsu PC210-8, Руководство по ремонту

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40 Troubleshooting UEN00247-00
PC210, 230, 240-8
5
2. Malfunction finding procedures
A number of procedures to determine the correct cause of a certain malfunction are described below.
Procedure to check the correct working of the grease pressure switch and cable
1. Disconnect the 2-pole connector from the pressure switch.
2. Measure the resistance between the two contacts using a multimeter.
When the system is pressureless, the contact of the switch should be open. If required, remove the switch to
make sure that no pressure below the pressure switch is present. Remove only the upper part, the diverter
valve can be left in place.
When the adjusted pressure (see side of relevant switch) is reached the contact should close.
3. Start a test cycle by pressing the push-button on the pump.
4. If possible, mount a pressure gauge between the diverter valve and the pressure switch to check the
switching moment.
WARNING:
k
Use a pressure gauge that is suitable for a grease pressure up to 250 bar.
Because the connector of the grease pressure switch is disconnected, the control unit cannot switch off the
pump when the adjusted pressure is reached.
5. Therefore turn off the contact switch, when the switching pressure has been reached. The test cycle is
ended.
If the grease pressure switch functions properly, the cable should be checked for breaks (internally) in the
cable.
6. Disconnect the pump connector.
7. Connect both contacts of the connector of the grease pressure switch with a separate wire.
8. Measure the resistance between pin 7 and 8 of the pump connector.
The measured resistance should be nearly zero.
9. Remove the wire between the contacts of the connector of the grease pressure switch.
The multimeter should read an
open-load .
Malfunction Cause Solution
11. The green lamp flashes
(0,2 s on - 0,2 s off) continu-
ously. A continuous-test cycle is carried out. The green lamp goes off after
the test. This is after turning
off the key switch.
12. The laptop and software
shows a ‘communication
error’. a. Bad connection (breaking in a wire,
connector). a. Check wire and connector.
b. After switching on the laptop and soft-
ware pushed a button too quickly. b. Repeat start-up procedure
and wait 8 s before switching
on laptop and software.
c. Supply voltage too low; e.g., because of
bad battery. c. Start the engine.
13. The laptop and software
shows ‘device not sup-
ported’. The laptop and software does not recog-
nise the control unit. A different laptop and soft-
ware is needed.