ENGINE (DIAGNOSTICS)(H4DOTC DIESEL) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC DETECTING CONDITION:

Immediately at fault recognition

TROUBLE SYMPTOM:

• Engine speed does not drop.

• Engine speed rise when accelerator pedal released

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode and Inspection Mode

WIRING DIAGRAM:

STEP	CHECK	YES	NO
1.CHECK FOR ANY OTHER DTC ON DISPLAY.	Is any other DTC displayed?	Check the appropriate DTC using the “List of Diagnostic Trouble Code (DTC)”.
2.CHECK POOR CONTACT. Check for poor contact in the ECM connector and the suction control valve connector.	Is there poor contact in ECM connector or suction control valve connector?	Repair the poor contact of ECM connector or suction control valve connector.
3.CHECK SUCTION CONTROL VALVE. Measure the resistance between suction control valve terminals. NOTE: Measure the resistance when suction control valve temperature is 20°C (68°F). Terminals No. 1 — No. 2:	Is the resistance 1.8 — 2.4 Ω?		Replace the fuel pump.
4.CHECK COMMON RAIL PRESSURE SENSOR. 1) Disconnect the connector from the common rail pressure sensor. 2) Measure the resistance between common rail pressure sensor terminals. Terminals No. 1 — No. 2: No. 2 — No. 3:	Is the resistance No. 1 — No. 2: approx. 13.7 kΩ and No. 2 — No. 3: approx. 2.5 kΩ?		Replace the common rail assembly.
5.CHECK FUEL DELIVERY LINE (LOW PRESSURE LINE). Check for damage in fuel delivery line (low pressure line), leaks at connection, and air entering into line. NOTE: To check for air in the system, replace the fuel hose between the fuel filter assembly to the fuel pump with an appropriate size clear oil proof/heat proof hose, and check the condition of the fuel when the engine is idled. After completing the check, make sure to restore the original fuel hose, and fill the fuel system by operating the priming pump.	Is there damage in fuel delivery line (low pressure line), leaks at connection, and air entering into line?	Identify the faulty parts, and repair. NOTE: In this case, repair the following item: • Air entering by fuel running out: start the engine to bleed the air completely. • Other than air entering by fuel running out: replace the faulty part.	Replace the fuel pump.