Lexus ES: Fuel Rail / System Pressure - Too Low (P008700)
DESCRIPTION
The high-pressure direct injection fuel system consists of a spill control valve, check valve, fuel relief valve, fuel pressure sensor, fuel pump assembly (for high pressure side) and direct fuel injector assemblies. The spill control valve adjusts the return volume of high-pressure fuel. The check valve mechanically opens and closes the paths to the fuel delivery pipes. The relief valve releases the fuel back to the fuel tank if there is a malfunction in the high-pressure fuel system. The fuel pump assembly (for high pressure side) is installed to the cylinder head cover (bank 1) and operated by a cam installed to the end of the exhaust camshaft.
Rotation of the camshaft moves the pump plunger inside the fuel pump assembly (for high pressure side) up and down, pressurizing the fuel. The pressurized fuel opens the check valve and is pumped into the fuel delivery pipe. The ECM controls the spill control valve to adjust the fuel pressure between 2 and 25 MPa (20 and 255 kgf/cm2) and monitors signals from the fuel pressure sensor (for high pressure side) to maintain the target fuel pressure.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory | Note |
|---|---|---|---|---|---|---|
| P008700 | Fuel Rail / System Pressure - Too Low | Although the ECM is not requesting the fuel pump assembly (for high pressure side) to open the spill control valve, fuel pressure decreases 5 MPa (51.0 kgf/cm2, 725 psi) from target pressure for about 10 seconds (1 trip detection logic). |
| Comes on | DTC stored | SAE Code: P0087 |
MONITOR DESCRIPTION
If the fuel pressure decreases despite an increase request signal being sent to the fuel pump assembly (for high pressure side) by the ECM, the ECM will illuminate the MIL and store this DTC.
MONITOR STRATEGY
| Related DTCs | P0087: Fuel pressure too low |
| Required Sensors/Components (Main) | Fuel pressure sensor (for high pressure side) |
| Required Sensors/Components (Related) | - |
| Frequency of Operation | Continuous |
| Duration | About 10 seconds |
| MIL Operation | Immediate |
| Sequence of Operation | None |
TYPICAL ENABLING CONDITIONS
| Monitor runs whenever the following DTCs are not stored | None |
| Time after engine start | 0.2 seconds or more |
| Time after fuel cut finished | 3 seconds or more |
| Target fuel pressure | Small change |
TYPICAL MALFUNCTION THRESHOLDS
| Both of the following conditions are met | - |
| Difference in fuel pressure between actual and target | Less than -5 MPa (-51.0 kgf/cm2, -725 psi) |
| Actual discharge rate of high pressure fuel pump | 400 mm3/st or more |
CONFIRMATION DRIVING PATTERN
HINT:
-
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here
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- Permanent misfire and fuel system DTCs can only be cleared when performing the universal trip driving pattern when no malfunction is detected.
- Connect the Techstream to the DLC3.
- Turn the engine switch on (IG).
- Turn the Techstream on.
- Record the Freeze Frame Data.
- Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
- Turn the engine switch off and wait for at least 30 seconds.
- Start the engine.
- Turn Techstream on.
- Based on the engine speed, engine load and other conditions displayed in the freeze frame data, reproduce the conditions present when the DTC was stored.
- Enter the following menus: Powertrain / Engine / Trouble Codes.
-
Read the pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.
- Input the DTC: P008700.
-
Check the DTC judgment result.
Techstream Display
Description
NORMAL
- DTC judgment completed
- System normal
ABNORMAL
- DTC judgment completed
- System abnormal
INCOMPLETE
- DTC judgment not completed
- Perform driving pattern after confirming DTC enabling conditions
HINT:
- If the judgment result is NORMAL, the system is normal.
- If the judgment result is ABNORMAL, the system has a malfunction.
CAUTION / NOTICE / HINT
HINT:
Read freeze frame data using the 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 help determine if the vehicle was moving or stationary, 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.
PROCEDURE
| 1. | CHECK FUEL LEAK |
(a) Check around and beneath the vehicle for fuel leaks, fumes, etc.
OK:
No fuel leaks present.
| NG | .gif) | REPAIR OR REPLACE FUEL LEAK POINT |
|
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| 2. | CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P008700) |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Powertrain > Engine > Trouble Codes| Result | Proceed to |
|---|---|
| DTC P008700 is output | A |
| DTC P008700 and other DTCs are output | B |
HINT:
If any DTCs other than P008700 are output, troubleshoot those DTCs first.
| B | | GO TO DTC CHART |
|
| 3. | CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST |
(a) Has the vehicle run out of fuel in the past?
| YES | | DTC CAUSED BY RUNNING OUT OF FUEL |
|
| 4. | READ FREEZE FRAME DATA (TARGET FUEL PRESSURE (LOW) / TARGET FUEL PRESSURE 2 AND LOW FUEL PRESSURE SENSOR) |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Using the Techstream, confirm the vehicle conditions recorded in the freeze frame data which were present when the DTC was stored.
Powertrain > Engine > DTC(P008700) > Freeze Frame Data| Tester Display |
|---|
| Target Fuel Pressure (Low) / Target Fuel Pressure 2 |
| Low Fuel Pressure Sensor |
HINT:
- Check the freeze frame data sets recorded the moment the DTC was stored and after the DTC was stored.
- Using the freeze frame data, confirm the vehicle conditions when the DTC was stored, such as if the engine was idling with the shift state P, D or N or if the vehicle was being driven at a constant speed or accelerating.
(e) Compare the difference in pressure between "Target Fuel Pressure (Low) / Target Fuel Pressure 2 and Low Fuel Pressure Sensor".
| Result | Proceed to |
|---|---|
| Difference between Target Fuel Pressure (Low) / Target Fuel Pressure 2 and Low Fuel Pressure Sensor is within 200 kPa | A |
| Difference between Target Fuel Pressure (Low) / Target Fuel Pressure 2 and Low Fuel Pressure Sensor is more than 200 kPa | B |
| B | | GO TO FUEL PUMP CONTROL CIRCUIT |
|
| 5. | CHECK MISFIRE COUNT OF DIRECT INJECTION |
(a) Connect the Techstream to the DLC3.
(b) Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Mode / Direct / Data List / Coolant Temperature, Injection Mode and Misfire Count Cylinder #1 to Misfire Count Cylinder #6.
Powertrain > Engine > Active Test| Active Test Display |
|---|
| Control the Injection Mode |
| Data List Display |
|---|
| Coolant Temperature |
| Injection Mode |
| Misfire Count Cylinder #1 |
| Misfire Count Cylinder #2 |
| Misfire Count Cylinder #3 |
| Misfire Count Cylinder #4 |
| Misfire Count Cylinder #5 |
| Misfire Count Cylinder #6 |
(e) According to the display on the Techstream, read the Data List with the Active Test "Control the Injection Mode" set to Direct.
| Injection Mode | Misfire Count | Proceed to |
|---|---|---|
| Direct | No misfire counts, or misfire counts occur randomly in all cylinders | A |
| Misfire counts occur in a particular cylinder | B |
HINT:
Perform "Inspection After Repair" after replacing the direct fuel injector assembly.
Click here
| B | | REPLACE DIRECT FUEL INJECTOR ASSEMBLY |
|
| 6. | CHECK FUEL PRESSURE SENSOR (FOR HIGH PRESSURE SIDE) |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Data List / Fuel Pressure (High).
Powertrain > Engine > Data List| Tester Display |
|---|
| Fuel Pressure (High) |
(e) Start the engine.
(f) Check that the fuel pressure fluctuates when the engine condition changes from idling to racing.
| Result | Proceed to |
|---|---|
| Fuel pressure does not rise | A |
| Fuel pressure does not fluctuate | B |
| Fuel pressure fluctuates | C |
HINT:
Perform "Inspection After Repair" after replacing the fuel pressure sensor (for high pressure side).
Click here
| B | | REPLACE FUEL DELIVERY PIPE WITH SENSOR ASSEMBLY LH (FUEL PRESSURE SENSOR (FOR HIGH PRESSURE SIDE)) |
| C | | GO TO STEP 9 |
|
| 7. | CHECK FUEL PUMP OPERATION (FOR LOW PRESSURE SIDE) |
(a) Check the fuel pump operation (for low pressure side).
Click here
| NG | | GO TO FUEL PUMP CONTROL CIRCUIT |
|
| 8. | CHECK FUEL PRESSURE (FOR LOW PRESSURE SIDE) |
(a) Check the fuel pressure (for low pressure side).
Click here
| NG | | REPAIR OR REPLACE FUEL SYSTEM |
|
| 9. | REPLACE FUEL PUMP ASSEMBLY (FOR HIGH PRESSURE SIDE) |
(a) Replace the fuel pump assembly (for high pressure side).
Click here
HINT:
Perform "Inspection After Repair" after replacing the fuel pump assembly (for high pressure side).
Click here
|
| 10. | CLEAR DTC |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTC.
Powertrain > Engine > Clear DTCs(e) Turn the engine switch off and wait for at least 30 seconds.
|
| 11. | CHECK IF DTC OUTPUT RECURS (SEE IF DTC P008700 IS OUTPUT AGAIN) |
(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(b) Enter the following menus: Powertrain / Engine / Trouble Codes.
(c) Read the DTCs.
Powertrain > Engine > Trouble Codes| Result | Proceed to |
|---|---|
| DTCs are not output | A |
| DTC P008700 is output | B |
| A | | END |
| B | | REPLACE ECM |
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