JLG 1850SJ, Руководство по обслуживанию и ремонту, Страница: 161 / 712

SECTION 3 - CHASSIS & TURNTABLE
3121619 3-111
1900 279 524195 14 The standstill request of detected crystalli-
zation is ignored for more than
5h(>300min)
This will be activated if there is a standstill
request activated by Crystalisation Monitor-
ing. Back pressure upstream SCR catalyst has
reached a level which indicates
crystallisation inside of exhaust line.
The error detection depends on the sensed pres-
sure upstream of the SCR catalyst and
the calculated exhaust volume flow through
the mixer pipe.
In case of error is set, but no crystallisation can
be found in the mixing pipe, a possible
reason can be the defect sensors:
- exhaust pressure & temperature upstream of
the SCR catalyst,
- the ambient pressure
- the exhaust mass flow => Check air path sys-
tem at the engine. Dismount urea injector from exhaust line and
inspect visually the injector and the
exhaust line for urea crystallisation upstream of
SCR catalyst:
If crystallisation can be clearly seen, then stand-
still must be processed.
Has the engine been operated in low load for
longer time? If yes, then it could be the
reaoson for crystallisation.
Does the NOx-Sensors work properly? Compare
ComRxSCR_rNOxUs to
ComRxSCR_rNOxDs, when
ComRxSCR_stNOxRdyUs = 1 &
ComRxSCR_stNOxRdyDs = 1 (Warm engine
and EAT-system,
SCRT_tCatAvrgExhGs_mp > 250°C,
SCR_stStatus = "Dosing" = 8): sensed NOx
upstream of SCR catalyst must be higher than
downstream of SCR catalyst.
Go to idle and wait until SCR system enters sta-
tus "stand-by" (no dosing),
SCRT_tCatAvrgExhGs_mp < 225°C:
ComRxSCR_rNOxUs = ComRxSCR_rNOxDs
Clean urea injector: rinse it thourougly under
water
Check EGR-Path: difference pressure sensor at
venturi tube, EGR cooler, EGR-Valve,
Reed-Valve, Intake throttle regarding function
and leakage. Does the EGR-cooler leak
water in the exhaust?
Check air path for leakage
Check turbocharger
No crystallisation can be seen in the mixing
pipe:
Check exhaust pressure sensor upstream of SCR
catalyst (SCR_pSensUCatUsP):
tube, water in sensor?
Check environmental pressure sensor
(EnvP_p): plausible?
Check exhaust temperature sensor upstream of
SCR-catalyst (SCR_tSensUCatUsT):
plausible compared to Exh_tOxiCatUs &
Exh_tOxiCatDs e.g. when engine has idled for
20 minutes?
=> Run stand-still to remove crystallisation
and to reset the DFC
Table 3-10. Engine Fault Codes
Deutz
Code
Blink
Code
SPN FMI Description Possible Cause Action