ENGINE (DIAGNOSTICS)(H4DOTC DIESEL) > Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P0628 SUCTION CONTROL VALVE CIRCUIT (GROUND SHORT)

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

DTC P0628 SUCTION CONTROL VALVE CIRCUIT (GROUND SHORT)

DTC DETECTING CONDITION:

Immediately at fault recognition

TROUBLE SYMPTOM:

Engine noise

CAUTION:

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

WIRING DIAGRAM:

STEP	CHECK	YES	NO
1.CHECK FOR POOR CONTACT. Check for poor contact of the ECM connector and the suction control valve connector.	Is there poor contact of ECM connector or suction control valve connector?	Repair the poor contact of ECM connector or suction control valve connector.
2.CHECK HARNESS BETWEEN ECM AND SUCTION CONTROL VALVE CONNECTOR. 1) Turn the ignition switch to OFF. 2) Disconnect the connectors from ECM and suction control valve. 3) Turn the ignition switch to ON. 4) Measure the voltage between suction control valve connector and engine ground. Connector & terminal (E123) No. 1 (+) — Engine ground (−):	Is the voltage 10 V or more?	Repair the short circuit to power supply in harness between ECM connector and suction control valve connector.
3.CHECK HARNESS BETWEEN ECM AND SUCTION CONTROL VALVE CONNECTOR. 1) Turn the ignition switch to OFF. 2) Measure the resistance of harness between ECM connector and suction control valve connector. Connector & terminal (B134) No. 20 — (E123) No. 1: (B134) No. 7 — (E123) No. 2:	Is the resistance less than 1 Ω?		Repair the harness and connector. NOTE: In this case, repair the following item: • Open circuit of harness between ECM connector and suction control valve connector • Poor contact of coupling connector
4.CHECK HARNESS BETWEEN ECM AND SUCTION CONTROL VALVE CONNECTOR. Measure the resistance between suction control valve connector and engine ground. Connector & terminal (E123) No. 1 — Engine ground: (E123) No. 2 — Engine ground:	Is the resistance 1 MΩ or more?		Repair the short circuit to ground in harness between ECM connector and suction control valve connector.
5.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?	Even if DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again. NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.	Replace the suction control valve.