DIAGNOSTIC MANUAL
3.2. SYMPTOM 1 (MEDIUM DUTY): FREQUENT PARKED REGENS WITH NO ACTIVE
FAULT CODES (MORE THAN ONE PARKED REGEN PER DAY)
NOTE – Before beginning the following step-based diagnostics, perform all vehicle operational checks
page 5.
NOTE – SPN 3719 FMI 15 may be inactive when a frequent regen concern is present.
NOTE – SPN 3936 FMI 8 can be active for this symptom.
Step
Action
Decision
1
Check for a failed Air Management System (AMS) actuator.
1.
Using Electronic Service Tool (EST) with ServiceMaxx™
software, go to Tests > Load Test Specific Session and verify
Load Test Specific Session is unchecked.
2.
Go to Sessions > Performance and select the record snapshot
icon from the toolbar.
3.
Go to Tests > KOER Tests > Air Management Test.
When Air Management Test is complete, stop recording. Use the playback
feature in ServiceMaxx™, and graph the following signal values:
Signal Values:
•
Mass Air Flow (MAF) Mean Value (MMV)
•
Intake Manifold Pressure (IMP)
•
Exhaust Gas Recirculation (EGR) valve position
Does snapshot match Graph 1 or Graph 2 page 51?
Graph 1: Go to
step 2A
Graph 2:
Diagnose and
repair failed
actuator (See
Performance
Diagnostics
section in Engine
Diagnostic
Manual). After
repairs are
complete, retest
for original
problem.
8
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