Selective Catalytic Reduction (SCR) System (Final Tier 4 and Stage IV Engines)

N101661-UN-22MAY13

A - DEF Level Gauge

B - Normal Operation Range

C - DEF Symbol

D - Low DEF Level 1

E - Low DEF Level 2

IMPORTANT: It is unlawful to tamper with or remove any component of the aftertreatment system. It is also unlawful to use diesel exhaust fluid (DEF) that does not meet the specifications provided or to operate the vehicle with no DEF.

Using incorrect or unapproved aftertreatment components can cause damage to vehicle’s aftertreatment system and reduce ability of aftertreatment system to function correctly. Never interchange aftertreatment components between Interim Tier 4/Stage III B and Final Tier 4/Stage IV equipped vehicles.

NOTE: SCR system monitors quality of DEF flowing through it. If a fluid other than DEF at correct urea concentration is detected, system will display a diagnostic trouble code and engine will derate to 50 percent power.

SCR system supplies DEF to engine aftertreatment system. DEF works in conjunction with machine aftertreatment components to reduce emissions. See Fuel, Lubricants and Coolants section in this manual for specifications and information about DEF.

Machine electronic systems monitor DEF level to assure proper performance. Primary display unit shows current DEF level (A). Refilling DEF tank every time machine is refueled is recommended. See Filling DEF Tank in Prestarting Checks section of this manual.

DEF level and operation changes:

Normal Operation—When DEF level is within this range (B), DEF symbol (C) is on and machine operates normally. Always maintain fill within this level for uninterrupted performance.

Low DEF Level 1—When DEF level drops to first red bar (D), DEF indicator flashes.

Low DEF Level 2—When DEF level falls below this point (E), DEF indicator stops flashing. An audible alarm is present.

DEF Tank Empty—When The DEF tank is empty PUMP FAIL TO PRIME DTC will be displayed and engine power will be reduced by 50 percent when DTC is displayed. Engine perfomance will be restored when DEF tank is filled.

DEF freezes at -11°C (12°F) and will not flow to the SCR system. Machine systems sense low temperature and allow engine to start, even with no DEF flow. Engine coolant is used to thaw fluid in DEF tank when engine is running. If system senses that DEF has thawed and SCR system is operating normally within 60 to 90 minutes, machine operates normally. If DEF flow is not sensed within 60 to 90 minutes, FAIL TO THAW DTC is displayed. Machine is allowed to operate normally for four hours after DTC is displayed, if DEF flow is not sufficient after four hours engine power will be reduced to 50 percent until DEF flow is achieved. Freezing and thawing of DEF does not degrade it.

If desired, locking DEF tank cap and strainer/screen kits are available from your John Deere dealer.