Diagnostic Aids

After each service or repair procedure has been completed, repeat QUICK TEST to ensure all EEC-IV systems work properly and DTCs are no longer present. To keep battery from going dead when performing QUICK TEST, disconnect glow plug relay. Relay is located on top, right side of engine. Ignore DTC 0380 while glow plug relay is disconnected.

Quick test is made up of 7 functional tests of EEC-IV system. The following basic test steps must be followed in sequence to avoid misdiagnosis. All self-tests are completely menu driven using New Generation Star (NGS) scan tool.

• VISUAL CHECK 
• VEHICLE PREPARATION & EQUIPMENT HOOKUP 
• KEY ON ENGINE OFF (KOEO) SELF-TEST 
• KEY ON ENGINE RUNNING (KOER) SELF-TEST 
• RETRIEVE/CLEAR CONTINUOUS DTCS 
• KOEO INJECTOR ELECTRICAL SELF-TEST (BUZZ TEST) 
• KOEO OUTPUT STATE SELF-TEST 
• KOER SWITCH SELF-TEST 
• KOER CYLINDER CONTRIBUTION SELF-TEST