Navistar MaxxForce DT Diagnostic Manual page 121

Step
5D Check for Intake Manifold Pressure (IMP) issue. Use
the playback feature in ServiceMaxx™, and graph the
following signal values from Lug Down Test:
Signal Values:
• Engine Speed
• Intake Manifold Pressure (IMP)
• Accelerator Pedal Position 1 (APP1)
• Vehicle Speed
Compare snapshot to Graph 5 and associated Graph
Analysis page 127.
Is IMP operating per Graph 5 Graph Analysis?
Step
6
Verify exhaust gas temperatures are within specification.
1. Using Electronic Service Tool (EST) with
ServiceMaxx™ software, go to Sessions
> Performance and select the record
snapshot icon from the toolbar.
2. Go to Tests > KOER Aftertreatment Tests >
Onboard Filter Cleanliness Test.
When OBFCT is complete, stop recording. Use the
playback feature and graph the following signal values
from OBFCT:
Signal Values:
• Diesel Oxidation Catalyst Inlet Temperature
(DOCIT)
• Diesel Particulate Filter Inlet Temperature (DPFIT)
• Diesel Particulate Filter Outlet Temperature
(DPFOT)
• DPF Soot Load
Compare snapshot to Graph 6 and 8 page 129.
Which graph does snapshot most closely match?
Action
Action
https://www.truck-manuals.net/
DIAGNOSTIC MANUAL
Decision
Yes: Go to step 6
No: Diagnose and repair IMP issue
(See Performance Diagnostics section in
Engine Diagnostic Manual). After repairs
are complete, retest for original problem.
Decision
Graph 6: Diagnostics Complete
Graph 8: Go to step 7
117