Navistar MaxxForce DT Diagnostic Manual page 91

Step
6 Determine root cause of exhaust system contamination. (See
Engine Symptoms Diagnostics section in Engine Diagnostic
Manual.)
Step
7 Check Oxygen Sensor (O
allow to reach normal operating temperature. Using EST with
ServiceMaxx™ software, go to Sessions > Performance. Let
the engine idle for 5 minutes while monitoring O
signal value.
Is O S Temperature signal value greater than 1400°F (760°C)?
2
Step
8 Visually inspect Aftertreatment Fuel Injector (AFI) supply line
for leaks, kinks, bends, or other damage?
Is the AFI supply line leaking or damaged?
Action
Action
S) operation. Start the engine and
2
Action
https://www.truck-manuals.net/
After repairs are complete, go to
step 7
Yes: Go to step 8
S Temperature
2
No: Repair O
Electronic Control Systems
Diagnostics in Engine Diagnostic
Manual). After repairs are complete,
retest for original problem.
Yes: Replace AFI supply line. After
repairs are complete, go to step 10.
No: Go to step 9
DIAGNOSTIC MANUAL
Decision
Decision
S or circuit (See
2
Decision
87