jcb G20 Operator's Manual page 137

Cause
Coolant rusty, operation without correct mixture of
antifreeze and water.
Electrical
Step Trouble
1 Fuel supply fault
2 Engine does not start
Step Trouble
1 Sensor supply voltage fault
2 Sensor connection faulty
3 Sensor failure
4 Wiring fault
Step Trouble
1 Sensor supply voltage fault
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Table 46. Coolant - Contaminated
Remedy
Drain and flush the cooling system. Fill with correct
mixture of antifreeze and water.
Review the coolant change interval. Refer to the Op-
eration and Maintenance Manual.
Table 47. General Fuel System Faults
Action/Remedy
Check the low pressure circuit connections are secure.
Check the fuel pressure in low circuit/tank level.
Check the fuel type (EN590 Specification).
Check for the external diesel fuel leaks.
Check the filter is not blocked
Check the fuel lift pump operation
Replace/repair as necessary.
If no faults are found, proceed to Step 2 or 3 depending on
symptoms.
Complete the `Static Injector Leak Test'.
If the injector backleak is above the limit, replace injector(s) as
necessary.
If the injector backleak is OK check the rail pressure is above
300 bar, if not, replace the high pressure pump.
If the rail pressure is OK and backleak is within limits, raise
Techweb Helpdesk Call.
Table 48. General Sensor Fault
Action/Remedy
Disconnect the sensor, check sensor voltage supply at the
harness connector (see relevant sensor help file for pin num-
bers or refer to engine electrical schematic). If voltage supply
is faulty, disconnect all other sensor in turn until voltage supply
returns.
If sensor supply voltage is OK, proceed to Step 2.
Check the condition of sensor to harness connection, make
sure the seals are in place, check for signs of corrosion or con-
tamination. Repair/replace as necessary.
If no fault is found, proceed to Step 3.
Check the sensor resistance (see relevant helpfile page). If
sensor is out of specification replace.
If no faults is found, proceed to Step 4.
Check the harness continuity and machine and engine earth
contacts. Repair/replace as necessary.
If no fault found, raise Techweb Helpdesk call.
Table 49. Water in Fuel Sensor Fault
Action/Remedy
Check the presence of electrical supply on water sensor.
If sensor supply voltage is OK, proceed to Step 2.
9831/0650-3
Maintenance
Fault-Finding
130