Manitowoc 999, Service And Maintenance Manual

Page: 220 / 298

Reference
Only
POWER TRAIN 999 SERVICE/MAINTENANCE MANUAL
7-16
Published 05-16-17, Control # 233-03
Coolant Solenoid Valve
When needed, the DEF is heated by engine coolant which is
circulated through a heat exchanger in the tank. If the tank
temperature drops below 25
°
F (–4
°
C), the ECM will open the
coolant solenoid valve (2) to allow coolant to flow through the
heat exchanger.
Coolant Manifold
The coolant manifold (3) routes coolant flow to the system.
Air Bleed Valves
The air bleed valves (4) are used to bleed air from the
system when needed.
DEF Supply Module
The DEF supply module (5) is an electronically operated
pump and metering system controlled by the ECM. The
module pumps DEF to the dosing module (8) which is
mounted on the DRT module (7).
At engine shutdown, the DEF supply module enters a purge
cycle to prevent DEF from being left in the system, and in
cold climates, from potentially freezing. When it is in the
purge cycle, an audible click and pumping sound will be
heard from the module, and the module will pull out all of the
DEF in the system and return the DEF to the tank.
The DEF supply module is heated electrically and has a 10-
micron filter that requires periodic cleaning and inspection.
For filter maintenance intervals, refer to the engine
manufacturer’s manual.
SCR Module
The SCR module (6) incorporat es a cataly st, two
temperature sensors, an NH
3
sensor, and a NO
x
sensor.
The SCR module utilizes DEF (urea and deionized water) to
reduce NO
x
content in the exhaust gas to nitrogen.
The SCR module does not require maintenance.
Excessive NO
x
Warning System
If an excessive NO
x
warning is issued, check anything that
might cause an elevated NO
x
level, such as:
• Disconnected DEF tank level or quality sensor
• Blocked DEF hose or dosing module
• Disconnected dosing module
• Disconnected supply module
• Disconnected SCR wiring harness
• Disconnected NO
x
sensor
• EGR valve malfunction
Aftertreatment Protection System
The APS continually monitors exhaust gas temperatures. In
the event of excessive exhaust temperatures, the APS will
illuminate the HEST lamp in the cab.
The DRT module does not require maintenance.
DRT Module
DRT (7) is a tube mounted between the DOC module (8) and
the SCR module (6).
CAUTION
Loss of Power or Engine Shutdown Hazard!
If poor-quality DEF or a low-level condition is sensed, an
error code will be activated. These conditions can lead to
engine power being reduced (de-rated) by the ECM. If the
condition persists, engine shutdown may occur.
Refer to Section 3 of the 999 Operator Manual for
identification and location of the engine and exhaust
aftertreatment warning lights.
WARNING
Personal Injury or Equipment Damage Hazard!
Do not remove hoses from or attempt to service the DEF
supply module without first consulting the engine
manufacturer’s instructions. Personal injury and/or
equipment damage may result.
CAUTION
Use Only Approved Replacement Parts!
The DEF system components are designed to withstand
freezing and to be compatible with DEF fluid and the other
unique characteristics of the system. Use of non-
approved replacement parts may result in system
damage.
CAUTION
Loss of Power or Engine Shutdown Hazard
If NO
x
emissions exceed legislated limits, the operator will
be alerted by warning lights and audible warnings. If the
condition is not corrected in a set amount of time, an
engine derate and shutdown sequence will begin.
Refer to Section 3 of the 999 Operator Manual for
identification and location of the engine and exhaust
aftertreatment warning lights.