P1235

4GR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1235: High Pressure Fuel Pump Circuit
P1235 - High Pressure Fuel Pump Circuit

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 increases 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 1886 psi) according to the operating condition, and it feeds the fuel to the fuel delivery pipe.





MONITOR DESCRIPTION

The injector driver has the integrated circuit (IC) which monitors the electrical circuit between the spill control valve and injector driver. If an open circuit is detected, the IC sends the malfunction signal (FPD) to the ECM. Then, the ECM illuminates the MIL and sets a DTC immediately.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.

4. Turn the engine switch off and wait for at least 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on.

6. Start the engine.

7. Idle the engine for 10 seconds [A].

8. Enter the following menus: Powertrain / Engine / Trouble Codes.

9. Read the pending DTC [B].

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

11. Input the DTC: P1235.

12. Check the DTC judgment result.





HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result shows INCOMPLETE or N/A, perform steps [A] and [B] again.

13. If no DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
Read freeze frame data using Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction Freeze Frame Data.

PROCEDURE

1. INSPECT FUEL PUMP FOR HIGH PRESSURE

(a) Inspect the fuel pump for high pressure Fuel Pump (for High Pressure).

NG -- REPLACE FUEL PUMP FOR HIGH PRESSURE Removal
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (INJECTOR DRIVER - FUEL PUMP FOR HIGH PRESSURE)

(a) Disconnect the E58 injector driver (EDU) connector.

(b) Disconnect the E41 fuel pump for high pressure connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reconnect the injector driver (EDU) connector.

(e) Reconnect the fuel pump for high pressure connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (ECM - INJECTOR DRIVER)

(a) Disconnect the E6 ECM connector.

(b) Disconnect the E26 injector driver (EDU) connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reconnect the ECM connector.

(e) Reconnect the injector driver (EDU) connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. INSPECT ECM (FPD VOLTAGE)

(a) Turn the engine switch on (IG).

(b) Inspect the ECM using an oscilloscope.

(1) While cranking the engine, check the waveform the terminals of the ECM connector.









Standard:

Signal waveform appears as shown in the illustration.

HINT
The FPD terminal waveform is output only right after the engine starts. If this DTC is stored when the engine is started from engine switch off, the system enters fail-safe mode and the waveform is not output.

NG -- INSPECT ECM (FPD VOLTAGE)
OK -- Continue to next step.

5. INSPECT ECM (FPD AND FPF1 VOLTAGE)

(a) Turn the engine switch on (IG).

(b) Inspect the ECM using an oscilloscope.

(1) While cranking the engine, check the waveform the terminals of the ECM connector.









HINT
FPD terminal waveform is output only right after the engine starts.

Result:





HINT
*: If the FPF1 terminal waveform is similar to the FRF1 terminal waveform NG waveform 1, stop the engine and disconnect E26 injector driver (EDU) connector. Then, while cranking the engine, check to see if there is a difference between the FPF1 terminal waveform and the previous one.

B -- REPLACE INJECTOR DRIVER Removal

A -- REPLACE ECM Removal

6. INSPECT ECM (FPD VOLTAGE)

(a) Turn the engine switch on (IG).

(b) Disconnect the E26 injector driver (EDU) connector.

(1) While cranking the engine, check the waveform the terminals of the ECM connector.









Standard:

Signal waveform appears as shown in the illustration.

HINT
FPD terminal waveform is output only right after the engine starts.

NG -- REPLACE ECM Removal

OK -- REPLACE INJECTOR DRIVER Removal