DTC P1093 Fuel Rail Pressure (FRP) Too Low (4JJ3 without DPD)

Note

If the vehicle runs out of fuel, air may be entered in the fuel system. When there is air in the fuel piping, the smooth flow of fuel into the fuel supply pump is interrupted and this DTC may be set. Bleed air from the fuel piping after refilling.

1. Engine control system check

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Diagnostic system check-engine controls".

2. Fuel supply pump functional inspection

1) Perform the fuel supply pump functional inspection.

Refer to "202.Engine 15C.Functional Inspection(4JJ3 without DPD) fuel supply pump functional inspection".

Procedure completion

=>Go to Current DTC check.

3. Current DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is a DTC set?

Yes

=>Go to Fuel leakage inspection.

Go to Intermittent conditions of engine.

Refer to "202.Engine 15D.Symptom(4JJ3 without DPD) intermittent conditions of engine".

4. Fuel leakage inspection

1) Inspect that the fuel piping between the fuel tank and the fuel supply pump is properly connected, there are no cuts or cracks in the fuel hoses, and proper clamps are used. Is the result normal?

Note

The fuel piping between the fuel tank and the fuel supply pump is slightly vacuumed when the engine is running. Therefore, if the piping is not connected securely, air can get inside. If the engine speed or the engine load increases while air is in the fuel system, fluctuation in the fuel rail pressure occurs, and this DTC may be set.

2) Operate the priming pump until the force required for pressing increases.

Note

When a leak exists in the fuel system between the priming pump and fuel supply pump, the pushing weight of the priming pump does not get heavy.

3) Start the engine.

4) Inspect for a fuel leakage at the high-pressure side components between the fuel supply pump and the injector for the following. Is the result normal?

Fuel supply pump
Fuel rail
FRP reduction valve
FRP sensor
Fuel pipe between the fuel supply pump and the fuel rail
Fuel pipe between the fuel rail and the injector
Fuel pipe sleeve nut

Note

Check for fuel leakage from the high pressure piping inlet to the bottom of the cylinder head cover. If a fuel leakage exists, the engine oil level will rise. Inspect the engine oil for fuel contamination.
Remove and inspect the high-pressure pipe joints connected to the injectors for fuel leakage from the sleeve nuts. When foreign material is attached, replace the injector and the high pressure pipe.

5) Are all of the results normal?

Yes

=>Go to Inspection for leakage into the combustion chamber.

Repair the fuel leakage as necessary.

=>Go to Repair verification.

5. Inspection for leakage into the combustion chamber

1) Remove the glow plugs from the cylinder head.

2) Inspect for fuel leakage into the combustion chamber. Is the result normal?

Yes

=>Go to Prioritized DTC check.

Replace the injector in which fuel leakage was found and inspect the engine for any damage or poor engine compression.

Note

If an injector has been replaced, be sure to set the Injector ID Code on the ECM.

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) injector removal".

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) injector installation".

=>Go to Repair verification.

6. Prioritized DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Start the engine.

4) Observe the DTC information with a scan tool. Is DTC P009B, P0192, P0193, P0201, P0202, P0203, P0204, P1267, P1269, P2146, P2149, or P228A set at the same time?

Yes

Go to the applicable DTC diagnosis.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P009B Common Rail Pressure Relief Valve Drive Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0192 Fuel Rail Pressure Sensor Circuit Low".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0193 Fuel Rail Pressure Sensor Circuit High".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0201 Injector Circuit - Cylinder 1".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0202 Injector Circuit - Cylinder 2".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0203 Injector Circuit - Cylinder 3".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0204 Injector Circuit - Cylinder 4".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P1267 Common Rail Pressure Relief Valve Circuit 1 Low Voltage".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P1269 Common Rail Pressure Relief Valve Circuit High Voltage".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P2146 Fuel Injector Group 1 Supply Voltage Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P2149 Fuel Injector Group 2 Supply Voltage Circuit".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P228A Common Rail Pressure Relief Valve IC Circuit Error".

=>Go to DTC check when revving engine.

7. DTC check when revving engine

1) Turn OFF the ignition switch.

2) Set the shift lever to the neutral position and apply the parking brake.

3) Start the engine.

4) While observing the DTC information with a scan tool, depress the accelerator pedal from idle to full throttle several times. Is a DTC set?

Yes

=>Go to FRP sensor signal voltage check.

An intermittent problem due to foreign object in the fuel can be suspected.

Replace the fuel filter element.

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) fuel filter element removal".

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) fuel filter element installation".

=>Go to DTC follow-up check.

8. DTC follow-up check

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 1 minute or more.

3) Start the engine.

4) Operate the vehicle under the conditions for running the DTC.

5) Observe the DTC information with a scan tool. Is a DTC set?

Yes

=>Go to FRP sensor signal voltage check.

=>Go to Repair verification.

9. FRP sensor signal voltage check

1) Turn OFF the ignition switch.

2) Turn ON the ignition switch.

3) Observe the Fuel Rail Pressure (FRP) Sensor parameter on the scan tool. Is the Fuel Rail Pressure (FRP) Sensor parameter within the specified range?

Value: 0.6 to 0.8 V

Yes

=>Go to Injector inspection.

=>Go to FRP reduction valve resistance check.

10. FRP reduction valve resistance check

1) Disconnect the FRP reduction valve harness connector (E29).

Refer to "LHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

2) Measure the resistance of the FRP reduction valve with a DMM. Is the resistance within the specified range?

Value: 0.4 to 0.7 Ω At 20°C {68°F}

Yes

=>Go to FRP reduction valve circuit inspection.

Replace the fuel rail.

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) common rail (fuel rail) removal".

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) common rail (fuel rail) installation".

=>Go to Repair verification.

11. FRP reduction valve circuit inspection

1) Inspect for poor connections at the FRP reduction valve harness connector (pins 1 and 2 of E29). Is the connection status normal?

2) Inspect for poor connections at the ECM harness connector (pins 3 and 4 of E2). Is the connection status normal?

3) Inspect the circuit between the ECM (pins 3 and 4 of E2) and the FRP reduction valve (pins 1 and 2 of E29) for high resistance. Is the result normal?

Refer to "LHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to FRP sensor circuit inspection.

Repair the circuit or connection as necessary.

=>Go to Repair verification.

12. Injector inspection

1) Set the shift lever to the neutral position and apply the parking brake.

2) Start the engine.

3) Perform the Injector Cutoff with a scan tool.

4) Command each injector OFF and verify the engine speed changes for each injector. Are there any injectors that do not change the engine speed when commanded OFF?

Yes

Replace the injectors that do not change.

Note

If an injector has been replaced, be sure to set the Injector ID Code on the ECM.

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) injector removal".

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) injector installation".

=>Go to Repair verification.

=>Go to PCV circuit inspection.

13. PCV circuit inspection

1) Inspect for poor connections at the PCV harness connector (pins 1 and 2 of E27). Is the connection status normal?

2) Inspect for poor connections at the ECM harness connector (pins 5 and 6 of E2). Is the connection status normal?

3) Inspect the circuit between the ECM (pins 5 and 6 of E2) and the PCV (pins 1 and 2 of E27) for high resistance. Is the result normal?

Refer to "LHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

4) Are all of the results normal?

Yes

=>Go to Fuel rail pressure check.

Repair the circuit or connection as necessary.

=>Go to Repair verification.

14. FRP sensor circuit inspection

1) Inspect for poor connections at the FRP sensor harness connector (pins 1, 2, and 3 of E45). Is the connection status normal?

2) Inspect for poor connections at the ECM harness connector (pins 17, 27, and 29 of E2, and pin 30 of E3). Is the connection status normal?

3) Inspect the circuit between the ECM (pins 17, 27, and 29 of E2, and pin 30 of E3) and the FRP sensor (pins 1, 2, and 3 of E45) for high resistance. Is the result normal?

Refer to "LHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Engine Control (4JJ3 without DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

4) Are all of the results normal?

Yes

Replace the fuel rail.

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) common rail (fuel rail) removal".

Refer to "1.Engine 1C.Fuel System(4JJ3 without DPD) common rail (fuel rail) installation".

=>Go to Repair verification.

Repair the circuit or connection as necessary.

=>Go to Repair verification.

15. Fuel rail pressure check

1) Turn OFF the ignition switch.

2) Set the shift lever to the neutral position and apply the parking brake.

3) Start the engine.

4) While observing the Fuel Rail Pressure (FRP) parameter and Desired Fuel Rail Pressure (FRP) parameter on the scan tool, depress the accelerator pedal from idle to full throttle several times. Does the difference between the Fuel Rail (FRP) Pressure parameter and the Desired Fuel Rail Pressure (FRP) parameter show a value within the specified range quickly enough?

Note