Navistar N9, Diagnostic Manual

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30 1 DIAGNOSTIC TROUBLESHOOTING PROCEDURES
3.0 - Engine Hard to Start Operational Checkout Procedure
Overview
The following steps direct technicians to systematically troubleshoot engine hard to start conditions and to avoid
unnecessary repairs.
Step 1 Perform preliminary operational checkout procedure. Decision
Did you perform 1.0 Preliminary Vehicle Operational Checkout Procedure? Yes: Go to Step 2.
No: Go to 1.0 Preliminary
Vehicle Operational
Checkout Procedure
(page 23).
Step 2 Check for hard to start related Diagnostic Trouble Codes (DTC). Decision
Using Electronic Service Tool (EST) with ServiceMaxx™ software, check DTC
list for:
• SPN 94 Fuel Delivery Pressure (FDP)
• SPN 931 Electric Fuel Pump (EFP)
• SPN 164 Injection Control Pressure (ICP)
• SPN 679 Injection Pressure Regulator (IPR)
• SPN 636 Camshaft Position (CMP)
• SPN 637 Crankshaft Position (CKP)
• SPN 108, 158, 628, 629, 1136, 1387 Engine Control Module (ECM)
• 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 3251 Diesel Particulate Filter Differential Pressure (DPFDP)
• SPN 5541, 5543 Exhaust Back Pressure Valve (EBPV)
• 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) faults
• SPN 4287 Engine Compression Brake Pressure (ECBP)
Does EST DTC list have any of the fault codes listed above?
Yes: Go to Fault Code
Diagnostics (page 142)
for hard to start related
SPN.
No: Go to Step 3.