Dtc P1238 Injector Malfunction

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P1238)

CHECK HARNESS AND CONNECTOR (ENGINE WIRE HARNESS)

CHECK INJECTOR COMPENSATION CODE

READ VALUE USING INTELLIGENT TESTER (COMPENSATORY INJECTION VOLUME FOR EACH CYLINDER)

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

CHECK CYLINDER COMPRESSION PRESSURE OF MALFUNCTIONING CYLINDER

REPLACE INJECTOR ASSEMBLY

BLEED AIR FROM FUEL SYSTEM

REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING

CHECK WHETHER DTC OUTPUT RECURS (DTC P1238)

REPLACE ECM

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

REPAIR OR REPLACE HARNESS OR CONNECTOR

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

DESCRIPTION

HINT:

1. For more information on the injector assemblies and common rail system, refer to System Description (HILUX_TGN26 RM0000012WW02QX.html).
   
2. If DTC P1238 has been stored, refer to Diagnostic Trouble Code Chart (HILUX_TGN26 RM0000031HW04FX.html).
   

HINT:

1. The cylinder which has the compensation value, indicated by Injection Feedback Val #1, #2, #3 and #4, that varies from the other cylinders may be malfunctioning.
   
2. If DTC P0093 (fuel leaks from high-pressure area) is stored simultaneously, a leakage malfunction of a specific cylinder has probably occurred.
   
3. If DTC P0200 (open or short in the injector driver or injector circuit) is stored simultaneously, there is probably a faulty circuit located between the ECM and the injector assembly including the injector driver.
   
4. If only DTC P1238 (injector malfunction) has been stored, an injector assembly mechanical malfunction or insufficient compression (valve clearance, etc.) has probably occurred. An open or short malfunction of the ECM, injector driver or injector circuit is unlikely.
   

HINT:

1. If DTC P1238 is stored, the following symptoms may appear:
   
1. Rough idle
   
2. Poor driveability
   
2. After confirming DTC P1238, check the internal fuel pressure on the intelligent tester by entering the following menus: Powertrain / Engine and ECT / Data List / Fuel Press, Target Common Rail Pressure.
   Under a stable condition such as idling or running the engine at 2500 rpm without load, Fuel Press is within 5000 kPa of Target Common Rail Pressure.
   

MONITOR DESCRIPTION

1. P1238 (Injection malfunction, except open or short in injector circuit):
   This DTC will be stored if the engine speed fluctuation between each cylinder is large. The ECM monitors changes in the crankshaft rotation speed using the crankshaft position sensor in order to detect improper combustion. The camshaft position sensor also plays a role in determining which cylinder has the problem. The fluctuation counter increases when irregular crankshaft rotation speed variation exceeds the threshold with the engine idling. Therefore, if any one of the cylinders is operating poorly (rough idle), the ECM stores this DTC.
   

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

1. After replacing the ECM, the new ECM needs registration (HILUX_TGN26 RM0000012XK071X.html) and initialization (HILUX_TGN26 RM000000TIN04FX.html).
   
2. After replacing an injector assembly, the ECM needs registration (HILUX_TGN26 RM0000012XK071X.html).
   

HINT:

1. 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.
   
2. When this DTC is stored, be sure to carefully examine "Injection Feedback Val #1 to #4", "Injection Volume", "Fuel Press", "Target Common Rail Pressure", "Engine Speed", "MAF", "Coolant Temp" and "Vehicle Speed" in the freeze frame data.
   

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. Read the DTCs.
   

   Result

   Result	Proceed to
   P1238 is output	A
   P1238 and other DTCs are output	B

   HINT:

   1. If any DTCs other than P1238 are output, troubleshoot those DTCs first.
      
   2. If DTCs other than P1238 are not output, check the fuel condition before proceeding to the next step.
      

1. Check the wire harness and connector connections.
   

   OK:

   The wire harness and connectors have been connected securely and there are good connections.
   

1. Read the injector compensation codes (HILUX_TGN26 RM0000012XK071X_02_0003.html).
   

   OK:

   Compensation codes stored in the ECM match compensation codes of the installed injector assemblies.
   

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 / Injection Feedback Val #1 to #4.
   

4. Read the value.
   

   Standard value:

   The compensatory injection volume is less than 3.0 mm³/st
   

   HINT:

   1. If the fuel injector assembly is malfunctioning, the compensatory injection volume remains at 5.0 mm³/st.
      
   2. If there is a disconnection, the feedback value will increase and +5.0 mm³/st will be indicated, because it will become impossible for the injector assembly to inject.
      

5. Inspect and repair the cylinder that has an improper compensation value according to the following steps.
   

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.
   

4. Check the 4 cylinders in sequence to identify any faulty cylinders by performing the power-balance inspection.
   

   HINT:

   1. If the engine idle speed does not change when an injector assembly is disabled, the cylinder being tested is malfunctioning.
      
   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.
      

HINT:

Measure the compression of the cylinder that had a high speed during the "Check the Cylinder Compression" Active Test.

1. Check the cylinder compression pressure (HILUX_TGN26 RM000001473022X_01_0002.html).
   

1. Replace the injector assembly (HILUX_TGN26 RM000002SY102LX.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 RM000002SY8026X_01_0002.html).
   

1. Register the injector compensation code (HILUX_TGN26 RM0000012XK071X_02_0003.html).
   

2. Perform the injector pilot quantity learning (HILUX_TGN26 RM0000012XK071X_02_0009.html).
   

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 RM000000PDK120X.html).
   

4. Turn the ignition switch off for 30 seconds or more.
   

5. Start the engine.
   

6. Warm up the engine (engine coolant temperature is 70°C (158°F) or higher) and idle it for 60 seconds (the shift lever should be in neutral, and the A/C switch and all accessory switches should be off).
   

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

8. Read the pending DTCs.
   

   HINT:

   1. If no pending DTCs are output, proceed to the next step to check "All Readiness".
      
   2. Perform the following procedure using the tester to determine whether or not the DTC judgment has been carried out.
      

   1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
      

   2. Input DTC P1238.
      

   3. Check the DTC judgment result.
      
      

      Result

      Tester Display	Result	Proceed to
      Pending DTC	P1238 is output	A
      All Readiness	ABNORMAL	A
      	NORMAL	B

      HINT:

      If STATUS is INCOMPLETE or N/A, increase the idling time.

1. Replace the ECM (HILUX_TGN26 RM0000013Z001HX.html).
   

1. Repair or replace the harness or connector.
   

1. Connect the intelligent tester to the DLC3.
   

2. Clear the DTCs (HILUX_TGN26 RM000000PDK120X.html).
   

3. Turn the ignition switch off for 30 seconds or more.
   

4. Start the engine.
   

5. Warm up the engine (engine coolant temperature is 70°C (158°F) or higher) and idle it for 60 seconds (the shift lever should be in neutral, and the A/C switch and all accessory switches should be off).
   

6. Confirm that the DTC is not output again.
   

   HINT:

   Perform the following procedure using the tester to determine whether or not the DTC judgment has been carried out.

   1. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
      

   2. Input DTC P1238.
      

   3. Check that STATUS is NORMAL. If STATUS is INCOMPLETE or N/A, increase the idling time.