Navistar N9, Руководство по диагностике

Страница: 47 / 51

1 DIAGNOSTIC TROUBLESHOOTING PROCEDURES 43
11.0 - ECM Loss of Communication
Overview
Diagnose Engine Control Module (ECM) will not communicate with Electronic Service Tool (EST).
Possible Causes
• Theft Deterrent System
• Public CAN Circuit (terminating resistor, etc.)
• Any failed module on Public CAN
• Power and ground circuits to Diagnostic Connector
• Engine Control Module (ECM) power circuit (ECM fuse, ECM PWR Relay, etc.)
• ECM ground circuit
• Low Battery Voltage
• Faulty ECM
Test Procedure
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
Determine if Electronic Service Tool (EST) is working properly. Decision
A. Key-On Engine-Off (KOEO)
B. Connect EST with ServiceMaxx™ to a second vehicle and log in.
Does EST communicate properly with second vehicle?
Yes: Go to Step 3
No: Repair EST. After repairs
are complete, retest for original
problem.