Symptom Troubleshooting [Engine Control System)

Symptom Troubleshooting Wiring Diagram
- California Emission Regulation Applicable Model with LF ATX
- California Emission Regulation Applicable Model with LF MTX, L3
- Except for California Emission Regulation Applicable Model with LF ATX
- Except for California Emission Regulation Applicable Model with LF MTX, L3
Foreword
Intermittent Concern Troubleshooting
- Vibration Method
- Water Sprinkling Method
Engine Symptom Troubleshooting
Quick Diagnostic Chart
No. 1 Melting Of Main Or Other Fuses
No. 2 Mil Illuminates
No. 3 Will Not Crank
No. 4 Hard To Start/Long Crank/Erratic Start/Erratic Crank
No. 5 Engine Stalls-After Start/At Idle
No. 6 Cranks Normally But Will Not Start
No. 7 Slow Return To Idle
No. 8 Engine Runs Rough/Rolling Idle
No. 9 Fast Idle/Runs On
No. 10 Low Idle/Stalls During Deceleration
No. 11 Engine Stalls/Quits, Engine Runs Rough, Misses, Buck/Jerk, Hesitation/Stumble, Surges
No. 12 Lack/Loss Of Power-Acceleration/Cruise
No. 13 Knocking/Pinging-Acceleration/Cruise
No. 14 Poor Fuel Economy
No. 15 Emission Compliance
No. 16 High Oil Consumption/Leakage
No. 17 Cooling System Concerns-Overheating
No. 18 Cooling System Concerns-Runs Cold
No. 19 Exhaust Smoke
No. 20 Fuel Odor (In Engine Compartment)
No. 21 Engine Noise
No. 22 Vibration Concerns (Engine)
No. 23 A/C Does Not Work Sufficiently
No. 24 A/C Is Always On Or A/C Compressor Runs Continuously
No. 25 A/C Is Not Cut Off Under Wide Open Throttle Conditions
No. 26 Exhaust Sulphur Smell
No. 27 Fuel Refill Concerns
No. 28 Fuel Filling Shut Off Concerns
No. 29 Spark Plug Condition
Engine Control System Operation Inspection
- Input Signal System Inspection Procedure
  - Notes
  - Finding irregular signals
  - Locating the source of unusual signals
  - Variable resistance type 1 (TP sensor and EGR boost sensor)
  - Input signal system inspection for variable resistance type 1
  - Standard power supply system inspection for variable resistance type 1
  - GND system inspection for variable resistance type 1
  - Variable resistance type 2 (mass air flow (MAF) sensor and VSS)
  - GND system inspection for variable resistance type 2
  - Input signal system inspection for variable resistance type 2
  - Electrical supply system inspection for variable resistance type 2
  - Thermistor type (IAT sensor and ECT sensor)
  - Input signal system inspection for thermistor type
  - GND system inspection for thermistor type
- Main Relay Operation Inspection
- Intake Manifold Vacuum Inspection
- Electronic Throttle Control System Inspection
  - Engine coolant temperature compensation inspection
  - Load compensation inspection
  - Engine speed
  - Throttle position (TP) sweep inspection
- Variable Intake-air Control Operation Inspection
  - Notes
  - Rod operation (LF)
  - Rod operation (L3)
- Variable Tumble Control Operation Inspection
  - Notes
  - Rod operation
- Fuel Injector Operation Inspection
- Fuel Cut Control System Inspection
- Fuel Pump Operation Inspection
- Fuel Pump Control System Inspection
- Spark Test
- EGR Control System Inspection
- Purge Control System Inspection
- A/C Cut-Off Control System Inspection
- Cooling Fan Control System Inspection
- Variable Valve Timing Control System Operation Inspection
  - When idling cannot be continued
  - When idling can be continued
- Evaporative Emission (EVAP) System Leak Inspection
- EVAP system leak inspection using WDS or equivalent
  - EVAP system test outline
  - EVAP system test description
  - EVAP system malfunction judgment
- Evaporative system test procedure
- EVAP system leak inspection using leak tester