When the malfunction code is not confirmed by the DTC check and the problem still can not be confirmed in the basic inspection, perform troubleshooting according to the numbered order given in the table below.
Symptom
•Does not crank (Difficult to start)
Suspect area:
Starter
Starter relay
Neutral start switch circuit (A/T)
•Difficult to start at cold engine
Suspect area:
Intake heater control circuit
STA signal circuit
Heater idle-up switch circuit
Injection nozzle
Fuel filter
Engine ECU
Injection pump
•Difficult to start at hot engine
Suspect area:
STA signal circuit
Injection nozzle
Fuel filter
Compression pressure
Engine ECU
Injection pump
•Engine stall soon after starting
Suspect area:
Fuel filter
ECU power source circuit
Engine ECU
Injection pump
•Others (Engine stall)
Suspect area:
ECU power source circuit
Spill valve relay circuit
Engine ECU
Injection pump
•Incorrect first idle (Poor idling)
Suspect area:
Fuel filter
Engine ECU
Injection pump
•High engine idle speed (Poor idling)
Suspect area:
A/C signal circuit
STA signal circuit
Engine ECU
Injection pump
•Lower engine idle speed (Poor idling)
Suspect area:
A/C signal circuit
Injection nozzle
EGR control circuit
Compression pressure
Valve clearance
Fuel line (Air bleed)
Engine ECU
Injection pump
•Rough idling (Poor idling)
Suspect area:
Injection nozzle
Fuel line (Air bleed)
Intake heater control circuit
EGR control circuit
Compression pressure
Valve clearance
Engine ECU
Injection pump
•Hunting at hot engine (Poor idling)
Suspect area:
Injection nozzle
ECU power source circuit
Compression pressure
Fuel line (Air bleed)
Valve clearance
Engine ECU
Injection pump
•Hunting at cold engine (Poor idling)
Suspect area:
Injection nozzle
ECU power source circuit
Intake heater control circuit
Compression pressure
Fuel line (Air bleed)
Valve clearance
Engine ECU
Injection pump
•Hesitation/Poor acceleration (Poor drivability)
Suspect area:
Injection nozzle
Fuel filter
EGR control circuit
Compression pressure
Engine ECU
Injection pump
•Knocking (Poor drivability)
Suspect area:
Injection nozzle
EGR control circuit
Engine ECU
•Black smoke (Poor drivability)
Suspect area:
Injection nozzle
EGR control circuit
Engine ECU
Injection pump
•White smoke (Poor drivability)
Suspect area:
EGR control circuit
Intake heater control circuit
Injection nozzle
Fuel filter
Engine ECU
Injection pump
•Surging/Hunting (Poor drivability)
Suspect area:
Injection nozzle
Engine ECU
Injection pump