FUEL INJECTION (FUEL SYSTEMS)(H4DOTC DIESEL) > Fuel System Trouble in General

Phenomenon	Trouble and possible cause	Corrective action
Start failure	The fuel tank is empty or the fuel level in the tank is uneven.	• Replenish fuel. • Check sub fuel pump.
	Fuel freezing	• Heat the fuel filter and supply pump. • Check fuel heater.
	Fuel deterioration	Replace fuel.
	Air in the fuel line	• Check if the fuel level in the tank is uneven. • Check sub fuel pump. • Operate the priming pump. • Check fuel line joints.
	Clogged or damaged fuel line	• Check that no dust and other foreign matter is mixed in the fuel tank. • Replace the fuel filter. • Check the sub level sensor filter.
	Fuel line leakage	• Tighten the joint part. • Replace the fuel delivery pipes.
	Wear or damage of the inner side of the fuel pump	Replace the fuel pump.
	Defective suction control valve	Check fuel pump suction control valve.
	Defective common rail assembly	Check common rail assembly.
	Defective fuel injector	• Check fuel injector. • Verify the ID of each cylinder. • Perform compulsory learning mode.
Improper idling	Fuel freezing	• Heat the fuel filter and supply pump. • Check fuel heater.
	Fuel deterioration	Replace fuel.
	Air in the fuel line	• Check if the fuel level in the tank is uneven. • Check sub fuel pump. • Operate the priming pump. • Check fuel line joints.
	Clogged or damaged fuel line	• Check that no dust and other foreign matter is mixed in the fuel tank. • Replace the fuel filter. • Check the sub level sensor filter.
	Defective EGR control valve	Check EGR control valve.
	Defective common rail assembly	Check common rail assembly.
	Defective throttle body	Check throttle body.
	Defective fuel injector	• Check fuel injector. • Verify the ID of each cylinder. • Perform compulsory learning mode.
	Defective suction control valve	• Perform compulsory learning mode. • Check fuel pump suction control valve.
The engine is locked	Fuel pump is locked	Check fuel pump.
Engine vibration increases	Wear or damage of the inner side of the fuel pump	Replace the fuel pump.
	Fuel line leakage	• Tighten the joint part. • Replace the fuel delivery pipes.
	The fuel tank is empty or the fuel level in the tank is uneven.	• Replenish fuel. • Check sub fuel pump.
	Defective common rail assembly	Check common rail assembly.
	Defective fuel injector	• Check fuel injector. • Verify the ID of each cylinder. • Perform compulsory learning mode.
Insufficient output	Defective pressure limiter	Replace common rail assembly.
	Air in the fuel line	Operate the priming pump.
	Fuel line leakage	• Tighten the joint part. • Replace the fuel delivery pipes.
	Clogged or damaged fuel line	• Replace the fuel filter. • Check the sub level sensor filter.
	Fuel deterioration	Replace fuel.
	Defective throttle body	Check throttle body.
	Defective fuel injector	• Check fuel injector. • Verify the ID of each cylinder. • Perform compulsory learning mode.
	Wear or damage of the inner side of the fuel pump	Replace the fuel pump.
	Defective suction control valve	• Perform compulsory learning mode. • Check fuel pump suction control valve.
	Defective common rail assembly	Check common rail assembly.
A large quantity of white smoke emitted	Clogged or damaged fuel line	• Replace the fuel filter. • Check the sub level sensor filter.
	Defective fuel injector	Check fuel injector.
	Defective suction control valve	Check fuel pump suction control valve.
	Defective common rail assembly	Check common rail assembly.
	Fuel deterioration	Replace fuel.
A large quantity of black smoke emitted	Defective throttle body	Check throttle body.
	Defective fuel injector	• Check fuel injector. • Verify the ID of each cylinder. • Perform compulsory learning mode.
	Defective suction control valve	• Perform compulsory learning mode. • Check fuel pump suction control valve.
	Defective common rail assembly	Check common rail assembly.
Defective fuel meter	Defective fuel level sensor and sub level sensor	Check fuel level sensor and sub level sensor.
Defective fuel meter	Defective combination meter	Check the combination meter.

CAUTION:

Water removing agent for the fuel has the quality of mixing water with diesel fuel. Do not use the water removing agent to the fuel tank.

NOTE:

• In snow-covered areas, mountainous areas, skiing areas, etc. where ambient temperatures become quite low throughout the winter season, the fuel may freeze. Use the suitable type of fuel for the respective area (ambient temperature).

• When the vehicle is left unattended for an extended period of time, water may accumulate in the fuel tank. Fill fuel fully to prevent the problem.

• When water is accumulated in fuel filter, drain the water.