DTC P0627/78 Fuel Pump Control Circuit / Open |
DTC No. | DTC Detection Condition | Trouble Area |
P0627/78 | Open or short in suction control valve circuit for more than 0.5 seconds (1 trip detection logic) |
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Engine Speed | Fuel Pressure |
Idling | Approximately 30 to 40 MPa |
3,000 rpm (No engine load) | Approximately 50 to 70 MPa |
1.INSPECT SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE) |
Disconnect the S8 suction control valve connector.
Measure the resistance of the suction control valve.
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OK | |
2.CHECK WIRE HARNESS (SUCTION CONTROL VALVE - ECM) |
Disconnect the S8 valve connector.
Disconnect the E8 ECM connector.
Measure the resistance of the wire harness side connectors.
Tester Connection | Specified Condition |
S8-1 (PCV+) - E8-2 (PCV+) | Below 1 Ω |
S8-2 (PCV-) - E8-1 (PCV-) | Below 1 Ω |
S8-1 (PCV+) - E8-2 (PCV+) - Body ground | 10 kΩ or higher |
S8-2 (PCV-) - E8-1 (PCV-) - Body ground | 10 kΩ or higher |
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OK | |
3.CHECK ECM (PCV SIGNAL) |
While cranking or idling the engine, check the waveform of the ECM connector using an oscilloscope.
Tester Connection | Specified Condition |
E8-2 (PCV+) - E8-1 (PCV-) | Correct waveform is shown |
Tool Setting | Condition |
10 V/DIV., 5 msec./DIV. | Idling or cranking with warm engine |
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OK | ||
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