Fiat Kobelco EX355 Tier2, Technical Manual

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EX355 T5-5-9
TROUBLESHOOTING C
MALFUNCTION OF PREHEAT INDICATOR
Providing that:
•
Be sure to inspect wiring connections prior to
troubleshooting.
Reference:
•
The preheat system operates when the coolant
temperature is 10 °C (50 °F) or lower.
•
During preheat operation, the preheat indicator
stays ON for 8 seconds.
Connector (harness end connector terminals seen
from the open end side)
Monitor (20P)
29 30 31 32 33 34 35 36 37 38
39 40 41 42 43 44 45 46 47 48
3 2 1
6 5 4
NO
YES
Preheat indicator
comes ON even if
preheat system is
not in operation. Check if preheat
indicator goes OFF
when QOS controller
is disconnected.
With QOS controller
disconnected, remove
20P connector from
monitor. Check for
continuity between
monitor harness end
connector terminal
No.43 and vehicle
frame.
NO
YES
Faulty QOS controller
Faulty monitor.
Short-circuited harness
between QOS controller and
monitor.
•
Key switch : ON
NO
YES
Preheat indicator
does not come ON
during preheat op-
eration.
With QOS controller
disconnected, ground
harness end con-
nector terminal No.6
to vehicle frame.
Check if preheat indi-
cator comes ON.
With QOS controller
disconnected, remove
20P connector from
monitor. Check for
continuity between
monitor harness end
connector terminal
No.43 and vehicle
frame.
NO
YES
Faulty QOS controller
Faulty monitor.
Broken harness be-
tween QOS control-
ler and monitor.
•
Key switch : ON
• Without disconnecting
the connector, insert a
jumper wire such as a
clip into the back of the
connector and ground
to the vehicle frame.
Q.O.S. Controller