Navistar MaxxForce DT Diagnostic Manual page 22

DIAGNOSTIC MANUAL
Maximum TC1TOP Signal
Value During Cranking
15.7 psi (108 kPa)
1 psi (7 kPa)
-13 psi (-89 kPa)
Step
2 Determine if the Diesel Particulate Filter (DPF) is contaminated.
Remove the DPF (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.
Is the DPF contaminated?
Step
3
Determine if PDOC or DOC is contaminated. Remove the 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 PDOC and DOC contaminated?
Step
4 Determine if DPF, DOC, and PDOC are reusable see the DPF and
DOC reuse guidelines page 159.
Based on DPF and DOC Re-Use Guidelines, are the DPF, DOC,
and PDOC reusable?
18
Table 21 Example TC1TOP (Actual) Calculations
TC1TOP KOEO Signal Value
14.7 psi (101 kPa)
0 psi (0 kPa)
-14 psi (–96 kPa)
Action
Action
Action
https://www.truck-manuals.net/
Maximum TC1TOP Signal Value During
Cranking — TC1TOP KOEO Signal
Value = TC1TOP (Actual)
15.7 psi (108 kPa) – 14.7 psi (101 kPa) =
1 psi (7 kPa)
1 psi (7 kPa) – 0 psi (0 kPa) = 1 psi (7 kPa)
–13 psi (80 kPa) – (–14) psi (-96 kPa) = 1
psi (7 kPa)
Yes: Remove Pre-Diesel
Oxidation Catalyst
(PDOC) & Diesel
Oxidation Catalyst (DOC),
and then and then go to
step 4.
No: Go to step 5
Yes: Remove DPF, and
then go to step 4.
No: Go to step 5
Yes: Go to step 6
No: Replace failed
component(s). After
repairs are complete, go
to step 6.
Decision
Decision
Decision