Navistar N9, Diagnostic Manual

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36 1 DIAGNOSTIC TROUBLESHOOTING PROCEDURES
5.0 - Engine Running, Engine Under Load Operational Checkout Procedure
Overview
The following steps direct technicians to systematically troubleshoot engine running problems while under a
load.
Step 1 Perform preliminary operational checkout procedure. Decision
Did you Perform 1.0 Preliminary Vehicle Operational Checkout Procedure
(page 23)? Yes: Go to Step 2.
No: Go to 1.0 Preliminary
Vehicle Operational
Checkout Procedure (page
23).
Step 2 Check for Diagnostic Trouble Codes (DTCs). Decision
Yes: Go to Fault Code
Diagnostics for appropriate
SPN (page 11). Using Electronic Service Tool (EST) with ServiceMaxx™ software, check DTC list for:
• SPN 91, 2623 Accelerator Pedal Position (APP)
• SPN 94 Fuel Delivery Pressure (FDP)
• SPN 931 Electronic Fuel Pump (EFP)
• SPN 164, 3055 Injection Control Pressure (ICP)
• SPN 679 Injection Pressure Regulator (IPR)
• SPN 636 Camshaft Position (CMP)
• SPN 637 Crankshaft Position (CKP)
• SPN 27, 2791 Exhaust Gas Recirculation (EGR)
• SPN 110, 1659 Engine Coolant Temperature 1 (ECT1)
• SPN 175 Engine Oil Temperature (EOT)
• SPN 1209 Exhaust Back Pressure (EBP)
• SPN 3610 Diesel Particulate Filter Outlet Pressure (DPFOP)
• SPN 5541, 5543 Exhaust Back Pressure Valve (EBPV)
• SPN 3251 Diesel Particulate Filter Differential Pressure (DPFDP)
• SPN 51, 3464 Engine Throttle Valve (ETV)
• SPN 102 Intake Manifold Pressure (IMP)
• SPN 132 Mass Air Flow (MAF)
• SPN 651-656, 2797, 2798, 3055, 3659-3664, 4257 Injector (INJ)
• SPN 105 Intake Manifold Temperature (IMT)
Does EST DTC list have any of the above listed SPN?
No: Go to Step 3.