DTC    P1235    High Pressure Fuel Pump Circuit

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DESCRIPTION

The high pressure side fuel pump is attached to the insulator, which is attached to the cylinder head cover. The pump activates according to the position of the cam on the exhaust side camshaft (right bank).
The high pressure side fuel pump increase the pressure of the fuel supplied from the fuel pump in the fuel tank to 4 to 13 MPa (40.8 to 132.6 kgf/cm, 580 to 1,885 psi) according to the operating condition, and it feeds the fuel to the fuel delivery pipe.

DTC No.
DTC Detection Condition
Trouble Area
P1235
Open or short in high pressure side fuel pump circuit for 1 second or more
(1 trip detection logic)
  1. Open or short in high pressure side fuel pump
  2. High pressure side fuel pump
  3. ECM

WIRING DIAGRAM


A107177E02


INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

1.INSPECT HIGH PRESSURE SIDE FUEL PUMP
A081503E03

  1. Disconnect the E67 high pressure side fuel pump connector.

  1. Measure the resistance of the terminals of the high pressure side fuel pump.

    Standard resistance:
    Tester Connection
    		Specified Condition
    1 - 2
    		1.19 to 1.39 Ω at 20°C (68°F)

  1. Reconnect the high pressure side fuel pump connector.



NG
REPLACE HIGH PRESSURE SIDE FUEL PUMP
OK


2.CHECK HARNESS AND CONNECTOR (EDU - HIGH PRESSURE SIDE FUEL PUMP)
A107729E03

  1. Disconnect the E52 EDU connector.

  1. Disconnect the E67 high pressure side fuel pump connector.

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

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    FP+ (E52-3) - E67-1
    		Below 1 Ω
    FP- (E52-4) - E67-2
    		Below 1 Ω

    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    FP+ (E52-3) or E67-1 - Body ground
    		10 kΩ or higher
    FP- (E52-4) or E67-2 - Body ground
    		10 kΩ or higher

  1. Reconnect the EDU connector.

  1. Reconnect the high pressure side fuel pump connector.



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.INSPECT ECM (FPD AND FPF1 VOLTAGE)
A107730E02

  1. Start the engine, and check the waveforms between terminals FPF1 and E1, and FPD and E1 of the E45 and E7 ECM connectors.

HINT:
The correct waveform is as shown in the illustration.


ECM Terminal Name
CH1 :FPD (E45-33) - E1 (E7-7)
CH2: FPF1 (E45-32) - E1 (E7-7)
Tester Range
2 V/DIV.
5 msec./DIV.
Conditions
Idling with warm engine


OK
REPLACE ECM
NG


4.CHECK HARNESS AND CONNECTOR (EDU - ECM)
A107731E02

  1. Disconnect the E45 ECM connector.

  1. Disconnect the E51 EDU connector.

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

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    FPF1 (E45-32) - FPF1 (E51-7)
    		Below 1 Ω
    FPD (E45-33) - FPD (E51-8 )
    		Below 1 Ω

    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    FPF1 (E45-32) or FPF1 (E51-7) - Body ground
    		10 kΩ or higher
    FPD (E45-33) or FPD (E51-8 ) - Body ground
    		10 kΩ or higher

  1. Reconnect the ECM connector.

  1. Reconnect the EDU connector.



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE EDU