Navistar MaxxForce DT Diagnostic Manual page 30

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 diesel particulate filter. This is to
be done prior to removing the DPF.
1. The transmission must be in neutral and the parking
2. Start and idle the engine.
3. Rapidly snap the accelerator pedal from idle to full
4. During the engine accelerations, visually check for a
Is black smoke visible?
Step
7
Determine if Diesel Particulate Filter (DPF), Pre-Diesel Oxidation
Catalyst (PDOC), and Diesel Oxidation Catalyst (DOC) are
contaminated. Remove the DPF, PDOC, and DOC (see Exhaust
System Service Manual), and check for signs of lube oil and
coolant contamination.
NOTE – A black staining in the exhaust tailpipe can occur on
applications that experience high idle times. This is normal
and the DPF should NOT be replaced.
Are the DPF, PDOC, or DOC contaminated?
Step
8 Determine if DPF, DOC, and PDOC are reusable see DPF and
DOC reuse guidelines page 159.
Based on DPF and DOC Re-Use Guidelines, are the DPF, DOC,
and PDOC reusable?
26
Action
brake applied.
throttle. This can be performed multiple times.
heavy black smoke exiting the exhaust pipe.
Action
Action
https://www.truck-manuals.net/
Decision
Yes: Go to Symptom 5
(Medium Duty): Black smoke
page 44.
No: Go to step 11
Decision
Yes: Go to step 8
No: Go to step 9
Decision
Yes: Go to step 10
No: Replace failed
component(s). After repairs
are complete, go to step 10.