Dtc P1238 Injector Malfunction

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

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

CHECK HARNESS AND CONNECTOR (ENGINE WIRE HARNESS)

READ VALUE USING GTS (COMPENSATORY INJECTION VOLUME FOR EACH CYLINDER)

PERFORM ACTIVE TEST USING GTS (FUEL CUT FOR IDENTIFYING MALFUNCTION CYLINDER)

CHECK CYLINDER COMPRESSION PRESSURE OF MALFUNCTIONING CYLINDER

REPLACE INJECTOR ASSEMBLY

CHECK WHETHER DTC OUTPUT RECURS (DTC P1238)

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

DESCRIPTION

HINT:

1. For more information on the injector assembly and the common rail system refer to the System Description (Click here).
   
2. If DTC P1238 has been stored, refer to the Diagnostic Trouble Code (DTC) Table for Common Rail System (Click here).
   

HINT:

1. The cylinder which has the compensation value for Injection Feedback Val #1, #2, #3, #4, #5, #6, #7 and #8 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 the cylinder has probably occurred.
   
3. If DTC P062D (open or short in the No. 1 injector driver (EDU) or injector assembly circuit) is stored simultaneously, there is probably a faulty circuit located between the ECM and the injector assembly including the No. 1 EDU.
   
4. If DTC P062E (open or short in the No. 2 injector driver (EDU) or injector assembly circuit) is stored simultaneously, there is probably a faulty circuit located between the ECM and the injector assembly including the No. 2 EDU.
   
5. If only DTC P1238 (injector malfunction) has been stored, a injector assembly mechanical malfunction or insufficient compression (valve clearance, etc.) has probably occurred. An open or short malfunction of the ECM, EDU or injector assembly 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 GTS by entering the following menus: Powertrain / Engine and ECT / Data List / Common Rail Pressure, Target Common Rail Pressure.
   Under a stable condition such as idling or running the engine at 2500 rpm without load, Common Rail Pressure is within 5000 kPa of Target Common Rail Pressure.
   

MONITOR DESCRIPTION

1. P1238 (Injection malfunction, except open or short in injector assembly 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:

After replacing a injector assembly, the ECM needs registration (Click here).

HINT:

Read freeze frame data using the GTS. 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.

1. Connect the GTS to the DLC3.
   

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

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

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. Connect the GTS to the DLC3.
   

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

3. Start the engine and warm it up (engine coolant temperature is 75°C (167°F) or more), and then idle the engine for 1 minute or more.
   

4. Enter the following menus: Powertrain / Engine and ECT / Data List / Injection Feedback Val #1 to #8.
   

5. Read the value.
   

   Standard value:

   The compensatory injection volume is from -3.0 to 3.0 mm³/st.
   

   HINT:

   1. If the fuel injector is malfunctioning, the compensatory injection volume remains at -5.0 or 5.0 mm³/st.
      
   2. The compensatory injection volume is usually from -3.0 to 3.0 mm³/st.
      
   3. The numbers of the Data List item Injection Feedback Val #1 to #8 do not match the cylinder numbers (refer to the Diesel Injection section of the Data List) (Click here).
      

6. Any cylinders that have a higher compensatory injection volume than shown above are considered to be faulty. Use the following steps to inspect and repair the cylinders.
   

1. Connect the GTS to the DLC3.
   

2. Start the engine and turn the GTS on.
   

3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Select Cylinder Fuel Cut / #1 to #8.
   

4. Check the 8 cylinders in sequence to identify a faulty cylinder by performing the power-balance inspection.
   

   HINT:

   1. If the engine idle speed does not change when a fuel injector 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.
      

1. Check the cylinder compression pressure (Click here).
   

1. Replace the injector assembly (Click here).
   

1. Connect the GTS to the DLC3.
   

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

3. Clear the DTCs (Click here).
   

4. Turn the ignition switch off.
   

5. Start the engine.
   

6. Switch the ECM from normal mode to check mode (Click here).
   

7. Warm up the engine (engine coolant temperature is 75°C (167°F) or more) and idle it for 60 seconds.
   

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

9. Read the DTCs.
   
   

   Result

   Result	Proceed to
   P1238 is output	A
   No DTC is output	B

1. Replace the ECM (Click here).
   

1. Connect the GTS to the DLC3.
   

2. Clear the DTCs (Click here).
   

3. Turn the ignition switch off.
   

4. Start the engine.
   

5. Warm up the engine and idle it for 60 seconds.
   

6. Confirm that the DTC is not output again.
   

   HINT:

   Perform the following procedure using the GTS 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 UNKNOWN, increase idling time.