2016 Pierce Engine Exhaust After Treatment Flashcards
Beginning in 2007, these engines are equipped with varying specialized exhaust equipment designed to what?
Reduce Soot, Ash, & Nitrogen Oxide
What are two ways regeneration can occur?
- Naturally: exhaust hot enough to burn the soot off
- Require Intervention: Engine ECU or operator intervention
What is the solution of the DEF, urea, or Ad-Blue?
Solution is 32.5% urea and deionized water
What does the Amber Check Engine/Engine Warning light indicate?
Non-Critical System Fault
Can drive to the end of their shift, call service to remedy the problem
What does the Red Stop Engine light indicate?
Serious engine fault may result
Vehicle shut down as soon as safe to do so
Remain shut down until serviced
What does the Malfunction Indicator (MIL) light indicate?
Fault has occurred on emission related component:
After treatment system should be diagnosed/serviced at next opportunity
What does the MIL & Stop Engine light together indicate?
Vehicle stopped soon as it is safe to do so, serviced
What does it mean when the Diesel Particulate Filter (DPF) is illumiated?
Regeneration is necessary
What does it mean when the DPF light is on solid?
Low to Medium levels of build up
Requires Regeneration
- Ensure switch is not activated
- Initiate by challenging duty cycle/highway driving for least 20 minutes or pumping
- or perform parked regeneration
What does it mean when the DPF light is flashing?
Medium to High levels of build up
Requires regen ASAP
-Perform parked or more challenging duty cycle
What does it mean when there is a flashing DPF light flashing & Amber Check engine light on?
High Levels of build up
Regen required immediately
- Auto regen will not initiate
- MUST perform parked regen
What does it mean when there is flashing DPF light & Check engine light & RED Stop engine light?
If parked Regen not performed, Stop engine light will illuminate
-Should be stopped and remain shut down till serviced
What does it mean when there is a High Exhaust System Temperature (HEST) light on?
Active Regeneration has been initiated
- Exhaust temps above normal
- Will remain on till temps are below 977 F
What happens if the HEST light is ON and the vehicle speed has dropped below the threshold of 5 miles per hour?
Light will remain ON until speed increases -3 mph back above the speed threshold and regen process is finished
What is Passive Regeneration?
Occurs during normal engine operation, at higher engine speeds
- Exhaust temps high enough to oxidize the soot in the DPF
- No ECU or operator intervention required- see no difference in engine performance
- No extra fuel used
- Excessive exhaust temps dont occur
- DPF light may temp illuminate & extinguish reach moderately high level, reduces soot load naturally
What is Active Regeneration?
Controlled by ECU
- Removes collected soot by injecting small amount of fuel into exhaust stream
- Raises exhaust temperatures to provide heat needed to burn off accumulated soot and regenerate the DPF
- Regen can happen when truck being driven, stationary truck operations or pumping operations
When does the need for active regeneration occur more frequently?
Within low speed
Low load or stop and go conditions
DPF lamp illuminates when regen is needed:
operator can can duty cycle and allow active regen or
manually park regen
When will the system automatically activate a regeneration?
Speedometer showing above 5 mph or higher speed or pumping mode
Warning about parked regeneration:
- Causes high exhaust gas temperatures at zero mph
- Do not perform in an enclosed are
- Do not sit in parked vehicle with extended amount of time
- Do not perform while connected to exhaust extraction system
- If engine speed does not increase-contact cummins dealer
- 900 rpm
- does not need to be out of service to perform regen
What are the ways to stop a regen process?
Pressing brake
Throttle
or
Regen Inhibit Switch
When performing a regen, important info:
- Normal idle (high idle should be OFF
- Clear area 5 ft
- If indoors, pipe exhaust should be rated at 1500 F
- Keep foot of the throttle pedal and brake pedal
- DPF lamp must be on in order to start
- Regen takes 20-40 minutes or more
- Exhaust temps stay high at leat 3-5 minutes after completion
What is the Regeneration Inhibit Switch used for:
-Used to temporarily suspend an in process active regeneration
Ex: occur in location or situation that is not ideal, must be postponed
-Dont use for normal operation
Maintenance:
Removed, disassembled and cleaned with special machine to remove the ash build-up
-CEL will illuminate and fault code
Maintenance 200,000-400,000 miles or 6,750 hours
Use CES20081/API CJ-4 Oil
The Selective Catalytic Reduction (SCR) requires DEF. How many gallons does it hold?
4 1/2 gallons
Should refill reservoir when refilling fuel or at end of shift
What does it mean when no light is illuminated for DEF?
DEF level between full and 38% full
What does it mean when DEF symbol is on solid?
DEF level between 38% full and 12% full
What does it mean when DEF symbol is flashing?
DEF level below 12% full
What does it mean when DEF symbol is flashing and Check Engine light on solid?
DEF level below 5% full (1/4 gallon remaining)
What does it mean when DEF symbol flashing and Check engine light solid and MIL light solid?
DEF tank empty and system no longer maintain DEF pressure
What does it mean when DEF symbol flashing and check engine light solid and MIL light solid and Red stop engine lit solid?
DEF tank empty and ignored
Engine intentionally shut down or in extended idle
