ECD SYSTEM PROBLEM SYMPTOMS TABLE

When a malfunction is not confirmed by a DTC (Diagnostic Trouble Code) check and the cause of problem cannot be identified through a basic inspection, troubleshoot according to the priority order indicated in the table below.

ECD SYSTEM
Symptom Suspected area See page
Engine noise or vibrations 1. Fuel quality, or dirt in the fuel tank -
2. Air filter (dirt air filter, or blocked manifold) -
3. Fuel filter (clogged fuel filter) -
4. Injector (clogged, or seized injector) -
5. Mechanical of the engine (engine, exhaust pipe, transaxle, or seized A/C compressor) -
Poor acceleration (Poor driveability) 1. Fuel quality, or dirt in the fuel tank -
2. Engine oil level (too high) -
3. Throttle valve (for EGR) *1 -
4. Air filter (dirt air filter, or blocked manifold) -
5. Accelerator pedal position sensor -
6. Fuel filter (clogged fuel filter) -
7. Exhaust pipe (blocked exhaust pipe) -
8. Three-way catalytic converter (TWC) (clogged TWC) -
9. Engine compression -
10. Injector *2 (clogged, or seized injector) -
11. Mechanical of the engine -
12. Fuel pump -
Hesitation 1. Fuel pressure -
2. Engine coolant temperature sensor *3 -
Spontaneous acceleration 1. Accelerator pedal position sensor -
2. Engine coolant temperature sensor *3 -
Abnormal smoke emitted 1. Fuel quality, or dirt in the fuel tank -
2. Engine oil level (too high) -
3. Injector (clogged, or seized injector) -
4. Engine compression -
5. Air filter (dirt air filter, or blocked manifold) -
6. Ventilation valve -
7. Fuel supply system (decreased fuel pressure) -
8. Mechanical of the engine (valves, cylinder head, or cylinder head tightening) -
9. EGR valve *4 -
10. Intake air temperature sensor *5 -
11. Engine coolant temperature sensor *3 -
Overheat 1. Cooling system (engine coolant level, soiled radiator, cooling system for leaks, water pump, etc.) -
2. Fuel quality, or dirt in the fuel tank -
3. Engine oil level (too high) -
4. A/C compressor -
5. Mechanical of the engine (valves, cylinder head, or cylinder head tightening) -
6. Injector (clogged, or seized injector) -
7. Engine coolant temperature sensor *3 -
8. Cooling fan *6 -
Engine does not stop (When ignition switch OFF) 1. Supply voltage (for ignition switch) (power supply circuit and earth) -
2. Ignition switch -
3. ECM -
Excessive fuel consumption 1. Fuel quality -
2. Valve timing -
3. Fuel leak -
4. Air filter -
5. Engine oil level (too high) -
6. Three-way catalytic converter (TWC) (clogged TWC) -
7. Exhaust pipe (blocked exhaust pipe) -
8. Engine compression -
9. Injector (clogged, or seized injector) -
10. Mechanical of the engine -
11. Glow plug -
12. Vehicle condition -

Tech Tips


  • *1: Using the intelligent tester, read "EGR valve duty ratio" in the DATA LIST at idle. If the EGR valve duty ratio exceeds 30%, inspect the throttle valve (for EGR) or related circuit.

  • *2: Using the intelligent tester, read "Injection flow correction parameter" in the DATA LIST at idle and engine warmed up. If the injection flow correction parameter is not as specified, inspect the injector.

  • *3: Using the intelligent tester, read "Engine coolant temperature" in the DATA LIST. If the reading is different from the actual engine coolant temperature, inspect the engine coolant temperature sensor.

  • *4: Using the intelligent tester, perform the active test to operate the EGR valve. If the EGR valve does not operate, inspect the EGR valve.

  • *5: Using the intelligent tester, read "Intake air temperature" in the DATA LIST. If the reading is different from the actual intake air temperature, inspect the intake air temperature sensor.

  • *6: Using the intelligent tester, perform the active test to operate the cooling fan. If the cooling fan does not operate, inspect the cooling fan system.