jcb JS300 Service Manual page 386

Error Codes / Error Diagnosis (Automatic Temperature Control (ATC) System)
Effect Description
The unit cannot The high pressure switch
cool the cab The operates twice In 1 minute.
compressor
disengages.
Note: If, an Error code shows after one minute this can
show a system Error.
Effect Description
The unit cannot The low pressure switch opens
cool the cab The for longer than 1 minute.
compressor
disengages.
Note: If an Error code shows after one minute this can
show a system error.
Note: If an Error code shows instantly this can show a
wiring error.
Note: Battery reset may be required to remove the error
after repair.
B-17
Table 5. Error Code 1 - High Pressure Lock Out
Causes
The system is overcharged.
There is no power to the high
pressure switch.
There is a bad earth on the high
pressure switch.
There is a defective switch.
Table 6. Error Code 2 - Low Pressure Lock Out
Causes
The system is undercharged.
There is no power to the low
pressure switch.
There is a bad earth on the low
pressure switch.
There is a defective switch.
9813/5100-1
Section B - Body and Framework
Heater/Air Conditioning SYSTEM
Remedy
Check the continuity of switch
(usually open switch).
Check the gas in system and
recharge, refer to table.
Check for 24V at the switch.
Check the continuity between
ATC control module pin 33 and
switch.
Check the earth wire between
ATC control module pin 34 and
switch.
Replace the switch.
Note: If, an Error code shows instantly this can show a
wiring Error.
Remedy
Check the continuity of switch
(usually closed switch).
Check the gas in system and
recharge, refer to table.
Check for 24V at the switch.
Check the continuity between
ATC control module pin 35 and
switch.
Check the earth wire between
ATC control module pin 36 and
switch.
Replace the switch.
Fault Finding
B-17