Dtc P0093 Fuel System Leak Detected - Large Leak

DESCRIPTION

MONITOR DESCRIPTION

MONITOR STRATEGY

INSPECTION PROCEDURE

CHECK FOR FUEL LEAKS (IN HIGH-PRESSURE AREAS)

CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0093) AND RECORD STORED DTC AND FREEZE FRAME DATA (PROCEDURE 2)

CHECK FUEL RECEIVER GAUGE (AMOUNT OF FUEL)

ADD FUEL

CHECK WHETHER DTC OUTPUT RECURS (DTC P0093)

CHECK FREEZE FRAME DATA (INJECTION FEEDBACK VAL #1 TO #4)

READ VALUE USING INTELLIGENT TESTER (FUEL PRESS)

READ VALUE USING INTELLIGENT TESTER (INJECTION FEEDBACK VAL #1 TO #4)

CHECK ENGINE SPEED

CLEAN FUEL FILTER CASE AND REPLACE FUEL FILTER

BLEED AIR FROM FUEL SYSTEM

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (TEST THE FUEL LEAK)

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE CYLINDER #1 TO #4 FUEL CUT)

INSPECT INJECTOR ASSEMBLY (INSPECTION FOR VALVE CLOSING PROBLEM)

REPLACE INJECTOR ASSEMBLY OF MALFUNCTIONING CYLINDER

BLEED AIR FROM FUEL SYSTEM

REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING

READ VALUE USING INTELLIGENT TESTER (ENGINE SPEED)

INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)

INSPECT FUEL TEMPERATURE SENSOR (SENSOR OUTPUT)

CHECK FOR INTERMITTENT PROBLEMS

REPLACE CRANKSHAFT POSITION SENSOR

REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - FUEL PRESSURE SENSOR)

INSPECT ECM (FUEL PRESSURE SENSOR OUTPUT VOLTAGE)

REPLACE COMMON RAIL ASSEMBLY

BLEED AIR FROM FUEL SYSTEM

REPLACE FUEL TEMPERATURE SENSOR

CHECK WHETHER DTC OUTPUT RECURS (DTC P0093)

DESCRIPTION

HINT:

1. If the drop in the internal fuel pressure is large when injecting fuel, the ECM interprets this as a fault and stores P0093.
   
2. If P0093 is present, refer to "Diagnostic Trouble Code (DTC) Table for Common Rail System" (HILUX_TGN26 RM000000XSN02CX.html).
   

HINT:

When DTC P0093 is set, check the internal fuel pressure of the common rail by entering the following menus on the intelligent tester: Powertrain / Engine and ECT / Data List / Fuel Press.

Reference:

Engine Speed	Fuel Pressure
Idling	Approximately 30000 to 50000 kPa
3000 rpm (No engine load)	Approximately 60000 to 95000 kPa

MONITOR DESCRIPTION

1. This DTC indicates that fuel leaks exist in high pressure areas in the common rail system. The ECM constantly monitors the internal fuel pressure of the common rail after the engine is started. The ECM stores this DTC if the drop in the internal fuel pressure is large when injecting fuel.
   In the common rail system, high-pressure fuel is always supplied to the high-pressure areas including the fuel supply pump assembly, common rail assembly, injector assemblies and piping. The ECM adjusts the suction control valve opening angle to obtain the target internal fuel pressure.
   If this DTC is stored, the ECM enters fail-safe mode. In fail-safe mode, both fuel injection and fuel supply pump assembly operation are suspended, and then the engine is stopped. Before the engine is stopped, the ECM permits the vehicle to be driven for 1 minute. The ECM continues operating in fail-safe mode until the ignition switch is turned off.
   

MONITOR STRATEGY

INSPECTION PROCEDURE

NOTICE:

1. Soon after starting the engine, visually check for fuel leaks in the fuel line.
   
2. Inspect the fuses of circuits related to this system before performing the following inspection procedure.
   
3. After replacing the ECM, the new ECM needs registration (HILUX_TGN26 RM0000012XK070X.html) and initialization (HILUX_TGN26 RM000000TIN057X.html).
   
4. After replacing the fuel supply pump assembly, the ECM needs initialization (HILUX_TGN26 RM000000TIN057X.html).
   
5. After replacing an injector assembly, the ECM needs registration (HILUX_TGN26 RM0000012XK070X.html).
   

HINT:

Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are 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.

HINT:

1. The following can be deduced from the above freeze frame data:
   
1. The common rail fuel pressure dropped suddenly when the engine was being run at a moderate engine speed during engine warmup and DTC P0093 was stored at the point when data set 4 was recorded.
   
2. Injection Feedback Val #3 is 5.0 mm³/st which is large (the normal value is between -3.0 and 3.0 mm³/st) and indicates that the injector assembly of cylinder 3 may be malfunctioning.
   
2. Actual cause: In this case, foreign matter in the fuel is stuck inside an injector assembly causing the injector assembly to malfunction temporarily.
   In order to remove the foreign matter in the fuel (the main cause of the problem), the fuel filter case needs to be cleaned and the fuel filter needs to be replaced.
   

HINT:

*1: Fuel press suddenly decreases for a moment, and then recovers. This can be seen clearly by comparing it to target common rail pressure.

*2: Injection feedback Val #3 is 5.0 mm³/st which is large (the normal value is between -3.0 and 3.0 mm³/st) and indicates that the injector assembly of cylinder 3 may be malfunctioning.

1. Before starting the engine, visually check for fuel leaks from the fuel supply pump assembly, injector assembly, common rail assembly, and the fuel pipes in high-pressure areas.
   

   OK:

   No fuel leaks in high-pressure areas.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON and turn the intelligent tester on.
   

3. Enter the following menus: Powertrain / Engine and ECT / DTC.
   

4. Read the DTCs and freeze frame data.
   
   

   Result

   Result	Proceed to
   P0093 and "P0190, P0192 and/or P0193" are output	C
   P0093 and "P0335, P0339 and/or P0340" are output	B
   Except above	A

1. Check if the fuel level is low.
   
   

   Result

   Result	Proceed to
   The indicator (fuel warning light) is illuminated	A
   The indicator (fuel warning light) is not illuminated	B

1. Add fuel.
   

1. Using the hand pump mounted on the fuel filter cap, bleed the air from the fuel system. Continue pumping until the pump resistance increases.
   

   NOTICE:

   1. Hand pump pumping speed: Max. 2 strokes/sec.
      
   2. The hand pump must be pushed with a full stroke during pumping.
      
   3. When the fuel pressure at the supply pump inlet port reaches a saturated pressure, the hand pump resistance increases.
      
   4. If pumping is interrupted during the air bleeding process, fuel in the fuel line may return to the fuel tank. Continue pumping until the hand pump resistance increases.
      
   5. If the hand pump resistance does not increase despite consecutively pumping 200 times or more, there may be a fuel leak between the fuel tank and fuel filter element sub-assembly, the hand pump may be malfunctioning, or the vehicle may have run out of fuel.
      
   6. If a large amount of air remains inside the fuel system, the common rail pressure does not rise to the pressure range necessary for normal use, and the engine cannot be started.
      

2. Start the engine.
   

   NOTICE:

   1. If a large amount of air remains inside the fuel system, the starter may need to be cranked for 10 seconds or more to start the engine.
      
   2. Do not crank the engine continuously for more than 20 seconds. The battery may be discharged.
      
   3. Use a fully-charged battery.
      

   1. When the engine can be started, proceed to the next step.
      

   2. If the engine cannot be started, bleed the air again using the hand pump until the hand pump resistance increases. Then start the engine.
      

3. Turn the ignition switch off.
   

4. Connect the intelligent tester to the DLC3.
   

5. Turn the ignition switch to ON and turn the intelligent tester on.
   

6. Clear the DTCs (HILUX_TGN26 RM000000PDK11ZX.html).
   

7. Start the engine. (*A)
   

8. Enter the following menus: Powertrain / Engine and ECT / Active Test / Test the Fuel Leak. (*B)
   

9. Perform the following test 5 times with on/off intervals of 10 seconds: Active Test / Test the Fuel Leak. (*C)
   

10. Allow the engine to idle for 3 minutes or more after performing the Active Test for the fifth time. (*D)
    

    
    
    
    

11. Enter the following menus: Powertrain / Engine and ECT / DTC.
    

12. Read Current DTCs.
    

    1. When no DTCs are output, the air bleeding is completed.
       

    2. If any DTCs are output, proceed to the next step.
       

13. Repeat steps (*A) to (*D).
    

14. Clear the DTCs (HILUX_TGN26 RM000000PDK11ZX.html).
    

15. Start the engine and warm it up.
    

16. Confirm that the shift lever is in neutral and securely apply the parking brake.
    

17. Fully depress the accelerator pedal for 5 seconds, and then release it. (*E)
    

18. Rev the engine to 3000 rpm and fully release the accelerator pedal immediately after the engine reaches 3000 rpm. (*F)
    

19. Repeat procedures (*E) and (*F) 5 times.
    

    
    
    
    

20. Enter the following menus: Powertrain / Engine and ECT / DTC.
    

21. Read Current DTCs.
    
    

    Result

    Result	Proceed to
    DTC is output	A
    No DTC is output	B

1. Read the value of Injection Feedback Val #1 to #4 in the freeze frame data recorded in Procedure 2.
   
   

   Result

   Result	Proceed to
   Injection Feedback Val for at least one cylinder is 5 mm3/st in at least 1 set of freeze frame data	B
   Except above	A

   HINT:

   When there is a problem with the operation of an injector assembly due to foreign matter in the inside of the injector assembly, etc., the fuel injection volume decreases. As a result, the ECM gives instructions to increase the fuel injection volume, which causes Injection Feedback Val to increase.

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON and turn the tester on.
   

3. Clear the DTCs (HILUX_TGN26 RM000000PDK11ZX.html).
   

4. Enter the following menus: Powertrain / Engine and ECT / Data List / Fuel Press.
   

5. Start the engine.
   

6. Read the value of Fuel Press while cranking and idling the engine.
   
   

   Result

   Result	Proceed to
   The engine cannot be started or the engine can be started but Fuel Press is below 20000 kPa 2 seconds after the starter signal changes from OFF to ON	B
   Except above	A

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON and turn the tester on.
   

3. Start the engine and warm it up.
   

4. Enter the following menus: Powertrain / Engine and ECT / Data List / Injection Feedback Val #1 to #4.
   

5. Read the values.
   
   

   Standard:

   
   

   Tester Display	Engine Condition*	Normal Value
   Injection Feedback Val #1 Injection Feedback Val #2 Injection Feedback Val #3 Injection Feedback Val #4	Idling	-3.0 mm3/st to 3.0 mm3/st

   HINT:

   *: The A/C switch and all accessory switches should be off, the engine coolant temperature should be 70°C (158°F) or higher and the engine should be idled for 1 minute or more.

   
   

   Result

   Result	Proceed to
   Injection Feedback Val for at least one cylinder is more than 3 mm3/st and engine vibration is abnormally large	B
   Except above	A

   HINT:

   1. When there is a problem with the operation of an injector assembly due to foreign matter in the inside of the injector assembly, etc., the fuel injection volume decreases. As a result, the ECM gives instructions to increase the fuel injection volume, which causes Injection Feedback Val to increase.
      
   2. The ECM controls the system so that the sum of Injection Feedback Val for all of the cylinders is approximately 0 mm³/st. Even if the value of Injection Feedback Val for a cylinder is less than -3.0 mm³/st (-3.0 mm³/st is the lowest normal value), as long as the value of Injection Feedback Val for each of the other cylinders is 3.0 mm³/st or less, the injector assemblies are not malfunctioning.
      

1. Start the engine and drive the vehicle until the engine coolant temperature reaches 60°C (140°F) or higher.
   

2. Stop the vehicle and allow the engine to idle.
   

3. While checking the tachometer, fully depress the accelerator pedal for 5 seconds, and then release it.*1
   

4. Repeat procedure *1 5 times.
   
   

   Result

   Result	Proceed to
   No problems such as sluggishness or variations in the tachometer reading	A
   Except above	B

1. Clean the fuel filter case and replace the fuel filter.
   

   HINT:

   Be sure to clean the inside of the fuel filter case as the fuel injectors may not operate properly if the fuel filter is installed with foreign matter remaining inside the fuel filter case.

1. Bleed the air from the fuel system (HILUX_TGN26 RM000002SY802HX_01_0002.html).
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON and turn the tester on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Test the Fuel Leak / Data List / Fuel Press, Target Common Rail Pressure, and Target Pump SCV Current.
   

4. Take a snapshot with the intelligent tester during the Active Test.
   

   Text in Illustration

   *1	Snapshot Button

   HINT:

   Detailed graphs can be displayed by transferring the stored snapshot from the tester to a PC (personal computer) with Intelligent Viewer installed.

5. Measure the difference between the target fuel pressure (Target Common Rail Pressure) and the actual fuel pressure (Fuel Press) when the "Test the Fuel Leak" Active Test is performed (HILUX_TGN26 RM0000012X105YX.html).
   

   HINT:

   In order to obtain an exact measurement, perform the Active Test 5 times and measure the difference once each time the Active Test is performed.

   
   
   
   

   OK:

   The difference between the target fuel pressure and the actual fuel pressure 2 seconds after the Active Test starts is less than 10000 kPa.
   

   HINT:

   1. "Target Common Rail Pressure" is the target fuel pressure controlled by the ECM.
      
   2. "Fuel Press" is the actual fuel pressure.
      
   
   

   Result

   Result	Proceed to
   The difference between the target fuel pressure and the actual fuel pressure 2 seconds after the Active Test starts is less than 10000 kPa	A
   Except above	B

HINT:

Use this Active Test to determine the malfunctioning cylinder.

1. Connect the intelligent tester to the DLC3.
   

2. Start the engine and turn the tester on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Cylinder #1 to #4 Fuel Cut.
   

   HINT:

   1. If the engine idle speed does not change when an injector assembly is disabled, the cylinder being tested is malfunctioning. Record any malfunctioning cylinders.
      
   2. If the cylinder being tested is normal, there will be a significant change in idle speed when the fuel injection is stopped for that cylinder.
      

1. Remove the glow plug for all the cylinders (HILUX_TGN26 RM000000JIT00UX.html).
   

2. Visually check if there is fuel on the glow plugs.
   

   HINT:

   1. If there is fuel on a glow plug assembly, fuel may be leaking from an injector assembly.
      
   2. After replacing an injector assembly, make sure that the common rail pressure (fuel pressure) is within 5000 kPa (51.0 kgf/cm², 725 psi) of the target fuel pressure while cranking the engine.
      
   3. If there is fuel on a glow plug assembly, fuel may have mixed with the engine oil. Check the engine oil amount and whether the engine oil smells of diesel fuel. If the oil level is above the full line or the engine oil smells of diesel fuel, replace the engine oil.
      

3. Install the glow plug (HILUX_TGN26 RM000000JIQ00VX.html).
   

1. Replace the injector assembly of the malfunctioning cylinder (HILUX_TGN26 RM0000044TN00QX.html).
   

   NOTICE:

   1. When replacing the injector assembly for a cylinder, always be sure to use a new injection pipe.
      
   2. Follow the procedure in the repair manual and temporarily install the injection pipes and nozzle leakage pipe, and then correctly position the injector assemblies. After that, tighten parts according to the torque specifications.
      
   3. If the installation procedure is not performed correctly, injector assemblies may become out of position, which may cause the injector assemblies to deteriorate, resulting in malfunctions.
      
   4. If an injector assembly deteriorates and malfunctions, other problems such as knocking, rough idle, etc. may occur.
      
   5. If an injector assembly becomes out of position, it is possible that the seal between the injector assembly and injection pipe may become incomplete, resulting in a fuel leak.
      

1. Bleed the air from the fuel system (HILUX_TGN26 RM000002SY802HX_01_0002.html).
   

1. Register the injector compensation code (HILUX_TGN26 RM0000012XK070X_02_0003.html).
   

2. Perform the injector pilot quantity learning (HILUX_TGN26 RM0000012XK070X_02_0009.html).
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON and turn the tester on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Data List / Engine Speed.
   

4. Read the value while cranking and idling the engine.
   
   

   Standard:

   
   

   Tester Display	Engine Condition	Specified Condition
   Engine Speed	Cranking	50 to 400 rpm
   	Idling with warm engine	700 to 800 rpm

   HINT:

   The value should be the same as the actual engine speed and displayed with no interruption on the tester.

1. Connect the positive (+) probe of an oscilloscope to the fuel pressure sensor input terminal of the ECM connector and the negative (-) probe to the body ground.
   

   Text in Illustration

   *a	Component with harness connected (ECM)

2. Turn the ignition switch to ON.
   

3. Check for any noise in the waveform when vibration is applied to the wire harness and connectors between the fuel pressure sensor and ECM.
   

   
   
   
   
   

   Text in Illustration

   *1	Engine	*2	Engine Wire
   *3	Common Rail Assembly (Fuel Pressure Sensor)	4	Wire to Wire
   *5	ECM	-	-
   *a	Vibration Method (Reference)	-	-

   
   
   
   

   Standard Voltage:

   Tester Connection	Condition	Specified Condition
   C113-16 (PCR1) - Body ground	Vibration is applied to the wire harness and connectors	No noise in the waveform

   
   

   Result

   Result	Proceed to
   MIL comes on or noise present in the waveform	B
   Except above	A

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON and turn the tester on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Data List / Fuel Temperature.
   

4. Read the value.
   

   OK:

   The value is almost the same as the actual fuel temperature.
   

   HINT:

   1. When the engine is stopped and left overnight, the fuel temperature becomes the same as the ambient temperature.
      
   2. If there is a problem with the fuel temperature sensor, and a fuel temperature value lower than the actual fuel temperature is indicated, P0093 may be stored.
      

1. Check for intermittent problems (HILUX_TGN26 RM000000PDQ0Y1X.html).
   

1. Replace the crankshaft position sensor (HILUX_TGN26 RM0000013Z601PX.html).
   

   HINT:

   Before replacing the crankshaft position sensor, perform a wire harness inspection and if there are any problems with the wire harness, repair or replace it.

1. Repair or replace the harness or connector.
   

1. Connect the positive (+) probe of an oscilloscope to the fuel pressure sensor input terminal of the ECM connector and the negative (-) probe to the body ground.
   

2. Turn the ignition switch to ON.
   

3. Check for any noise in the waveform when vibration is applied to the wire harness and connectors between the fuel pressure sensor and ECM.
   

   Standard Voltage:

   Tester Connection	Condition	Specified Condition
   C113-16 (PCR1) - Body ground	Vibration is applied to the wire harness and connectors	No noise in the waveform

   Text in Illustration

   *a	Component with harness connected (ECM)

   
   

   Result

   Result	Proceed to
   MIL comes on or noise present in the waveform	A
   Except above	B

1. Replace the common rail assembly (HILUX_TGN26 RM0000044W300QX.html).
   

   HINT:

   Before replacing the common rail assembly, perform a wire harness inspection and if there are any problems with the wire harness, repair or replace it.

1. Bleed the air from the fuel system (HILUX_TGN26 RM000002SY802HX_01_0002.html).
   

1. Replace the fuel temperature sensor.
   

   HINT:

   Before replacing the fuel temperature sensor, perform a wire harness inspection and if there are any problems with the wire harness, repair or replace it.

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON and turn the tester on.
   

3. Enter the following menus: Powertrain / Engine and ECT / DTC.
   

4. Clear the DTCs (HILUX_TGN26 RM000000PDK11ZX.html).
   

5. Start the engine.
   

6. Warm up the engine (engine coolant temperature is 70°C (158°F) or higher).
   

7. Confirm that the shift lever is in neutral and securely apply the parking brake.
   

8. Fully depress the accelerator pedal for 5 seconds, and then release it. (*A)
   

9. Rev the engine to 3000 rpm and fully release the accelerator pedal immediately after the engine reaches 3000 rpm. (*B)
   

10. Repeat procedures (*A) and (*B) 5 times.
    

    
    
    
    

11. Enter the following menus: Powertrain / Engine and ECT / DTC.
    

12. Read the DTCs.
    

    OK:

    No DTCs are output.