IN−30 − INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS 5. PROBLEM SYMPTOMS TABLE The suspected circuits or parts for each problem symptom are shown in the table below. Use this table to troubleshoot the problem when a ”Normal” code is displayed in the diagnostic trouble code check but the problem is still occurring. Numbers in the table indicate the inspection order in which the circuits or parts should be checked. HINT:
When the problem is not detected by the diagnostic system even though the problem symptom is present, it is considered that the problem is occurring outside the detection range of the diagnostic system, or that the problem is occurring in a system other than the diagnostic system. Page Indicates the page where the flow chart for each circuit is located. Circuit Inspection, Inspection Order Indicates the circuit which needs to be checked for each problem symptom. Check in the order indicated by the numbers. Circuit or Part Name Indicates the circuit or part which needs to be checked. Problem Symptom PROBLEM SYMPTOMS TABLE High engine idle speed (Poor idling) 1.
A/C signal circuit (Compressor circuit) 2. ECM power source circuit AC−88 1. A/C signal circuit 2. Fuel pump control circuit idling) 1. Compression 2. Fuel pump control circuit 30 Author : Date: Symptom Suspect Area See page Engine does not crank (Does not start) 1. Starter and starter relay ST−2 ST−17 No initial combustion (Does not start) 1. ECM power source circuit 2. Fuel pump control circuit 3. Engine control module (ECM) DI−147 DI−151 IN−29 No complete combustion (Does not start) 1. Fuel pump control circuit DI−151 Engine cranks normally (Difficult to start) 1. Starter signal circuit 2. Fuel pump control circuit 3. Compression DI−144 DI−151 EM−3 Cold engine (Difficult to start) 1.
Starter signal circuit 2. Fuel pump control circuit DI−144 DI−151 Hot engine 1. Starter signal circuit 2. Fuel pump control circuit DI−144 DI−151