Dtc P0627/78 Fuel Pump Control Circuit / Open


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE)

CHECK WIRE HARNESS (SUCTION CONTROL VALVE - ECM)

CHECK ECM (PCV SIGNAL)

DTC P0627/78 Fuel Pump Control Circuit / Open


DESCRIPTION

HINT:
For more information on the supply pump (suction control valve) and the common rail system, refer to the system description (Toyota Fortuner RM0000012WW024X.html).

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)
  1. Open or short in suction control valve circuit
  2. Suction control valve
  3. ECM
HINT:
When DTC P0627/78 is set, check the internal fuel pressure of the common rail by entering the following menus on the intelligent tester: Powertrain / Engine / Data List / Fuel Press.

Reference:

Engine Speed
Fuel Pressure
Idling
Approximately 30000 to 40000 kPa
3,000 rpm (No engine load)
Approximately 30000 to 60000 kPa

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc P0627/78 Fuel Pump Control Circuit / Open


INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
NOTICE:
  1. If the supply pump is replaced, the ECM needs initialization (Toyota Fortuner RM0000012X2005X.html).
  2. If the ECM is replaced, the new ECM needs initialization (Toyota Fortuner RM0000012X2005X.html).
1.INSPECT SUPPLY PUMP ASSEMBLY (SUCTION CONTROL VALVE)
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc P0627/78 Fuel Pump Control Circuit / Open

  1. Disconnect the S8 suction control valve connector.

  1. Measure the resistance of the suction control valve.

    Standard resistance:
    1.9 to 2.3 Ω at 20°C (68°F)


NG
REPLACE SUPPLY PUMP ASSEMBLY
OK


2.CHECK WIRE HARNESS (SUCTION CONTROL VALVE - ECM)
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc P0627/78 Fuel Pump Control Circuit / Open

  1. Disconnect the S8 valve connector.

  1. Disconnect the E7 ECM connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    S8-1 (PCV+) - E7-2 (PCV+)
    		Below 1 Ω
    S8-2 (PCV-) - E7-1 (PCV-)
    		Below 1 Ω
    S8-1 (PCV+) - E7-2 (PCV+) - Body ground
    		10 kΩ or higher
    S8-2 (PCV-) - E7-1 (PCV-) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.CHECK ECM (PCV SIGNAL)
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.1Kd-Ftv Engine Control System.Ecd System. Dtc P0627/78 Fuel Pump Control Circuit / Open

  1. While cranking or idling the engine, check the waveform of the ECM connector using an oscilloscope.

    OK:
    Tester Connection
    		Specified Condition
    E7-2 (PCV+) - E7-1 (PCV-)
    		Correct waveform is as shown
    Tool Setting
    		Condition
    10 V/DIV., 5 msec./DIV.
    		Idling or cranking with warm engine
    HINT:
    The waveform varies depending on the suction control valve operation.


NG
REPLACE ECM
OK

CHECK FOR INTERMITTENT PROBLEMS