Navistar MaxxForce DT Diagnostic Manual page 101

Step
4 Determine if removed aftertreatment system components
need to be cleaned see DPF and DOC reuse guidelines
page 159.
Based on DPF and DOC Re-Use Guidelines, do any of the
removed aftertreatment system components need to be
cleaned?
Step
5
Determine root cause of exhaust system contamination.
(See Engine Symptoms Diagnostics section in Engine
Diagnostic Manual.)
Step
6
Diesel Particulate Filter (DPF) Snap Acceleration Test (Quick
Test). This procedure checks the DPF for cracks or internal
damage without removing the DPF from the vehicle and is
used to test basic functionality of the DPF. This is to be done
prior to removing the DPF.
1. The transmission must be in neutral and the
parking brake applied.
2. Start and idle the engine.
3. Rapidly snap the accelerator pedal from idle
to full throttle. This can be performed multiple
times.
4. During the engine accelerations, visually check
for a heavy black smoke exiting the exhaust
pipe.
Is black smoke visible?
Action
Action
Action
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DIAGNOSTIC MANUAL
Decision
Yes: Clean components using
appropriate cleaning equipment. After
cleaning procedure is complete, install
components and go to step 6.
No: Install removed aftertreatment
system components, and then go to
step 6.
Decision
After repairs are complete, go to step 7
Decision
Yes: Go to symptom 5 (Heavy Duty):
Black smoke page 113.
No: Go to step 7
97