ECD SYSTEM(for CCo), Diagnostic DTC:P1238

DTC Code	DTC Name
P1238	Injector Malfunction

DESCRIPTION

Tech Tips

For more information on the fuel injectors and the common rail system refer to the System Description Click here.
If DTC P1238 has been stored, refer to the Diagnostic Trouble Code Chart Click here.

The ECM detects combustion deterioration for a specific cylinder.

Tech Tips

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.
If DTC P0093 (fuel leaks from high-pressure area) is stored simultaneously, a leakage malfunction of a specific cylinder has probably occurred.
If DTC P062D (open or short in the injector driver (EDU) or fuel injector circuit) is stored simultaneously, there is probably a faulty circuit located between the ECM and the fuel injector including the EDU.
If only DTC P1238 (injector malfunction) has been stored, a fuel injector mechanical malfunction or insufficient compression (valve clearance, etc.) has probably occurred. An open or short malfunction of the ECM, EDU or fuel injector circuit is unlikely.

P1238
DTC Detection Drive Pattern	DTC Detection Condition	Main Trouble Area	Related Trouble Area
Warm up the engine and idle it for 60 seconds	A large engine speed fluctuation when idling continues for 60 seconds. (2 trip detection logic)	Fuel injector Injector driver (EDU) (P062D set simultaneously) Connector connection (P062D set simultaneously) Compression pressure	Valve timing Fuel with low cetane number used ECM

Related Data List
DTC No.	Data List
P1238	Injection Volume Injection Feedback Val #1 to #4 Fuel Press Target Common Rail Pressure

Tech Tips

If DTC P1238 is stored, the following symptoms may appear:

Rough idle
Poor driveability

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

P1238 (Injection malfunction, except open or short in fuel 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

Refer to DTC P062D Click here.

CAUTION / NOTICE / HINT

Note

After replacing the ECM, the new ECM needs registration (See page ) and initialization Click here.
After replacing a fuel injector, the ECM needs registration Click here.

Tech Tips

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.
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.

PROCEDURE

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

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / DTC.

Read the DTCs.

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

Tech Tips

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

GO TO DTC CHART Click here

CHECK HARNESS AND CONNECTOR (ENGINE WIRE HARNESS)
1. Check the wire harness and connector connections.
  
  OK
  
  The wire harness and connectors have been connected securely and there are good connections.
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

OK
CHECK FUEL INJECTOR COMPENSATION CODE
1. Read the injector compensation codes Click here.
  
  OK
  
  Compensation codes stored in the ECM match compensation codes of the installed fuel injectors.
NG
REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING Click here

OK
READ VALUE USING INTELLIGENT TESTER (COMPENSATORY INJECTION VOLUME FOR EACH CYLINDER)
1. Connect the intelligent tester to the DLC3.
2. Clear the DTCs Click here.
3. Turn the ignition switch off for 30 seconds or more.
4. Turn the ignition switch to ON and turn the tester on.
5. 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 (the shift lever should be in neutral, and the A/C switch and all accessory switches should be off).
6. Enter the following menus: Powertrain / Engine and ECT / Data List / Injection Feedback Val #1 to #4.
7. Read the value.
  
  Standard value
  
  The compensatory injection volume (Injection Feedback Val #1 to #4) is from -4.9 to 4.9 mm³/st.
  Tech Tips
  - If the fuel injector is malfunctioning, the compensatory injection volume remains at -5.0 or 5.0 mm³/st.
  - The compensatory injection volume is usually from -3.0 to 3.0 mm³/st.
  - Any cylinders that have a higher compensatory injection volume (Injection Feedback Val #1 to #4) than shown above are considered to be faulty. Use the following steps to inspect more deeply and repair the specific cylinders.
NEXT
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE CYLINDER #1 TO #4 FUEL CUT)
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.
  Tech Tips
  - If the engine idle speed does not change when a fuel injector is disabled, the cylinder being tested is malfunctioning.
  - 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.
NEXT
CHECK CYLINDER COMPRESSION PRESSURE OF MALFUNCTIONING CYLINDER

Tech Tips

Measure the compression of the cylinder that had a high speed during the Active Test "Check the Cylinder Compression".
1. Check the cylinder compression pressure Click here.
NG
CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION Click here

OK
REPLACE FUEL INJECTOR
1. Replace the fuel injector Click here.
NEXT
BLEED AIR FROM FUEL SYSTEM
1. Bleed the air from the fuel system Click here.
NEXT
REGISTER INJECTOR COMPENSATION CODE AND PERFORM PILOT QUANTITY LEARNING
1. Register the injector compensation code Click here.
2. Perform the fuel injector pilot quantity learning Click here.
NEXT

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

OK
Compensation codes stored in the ECM match compensation codes of the installed fuel injectors.

Standard value
The compensatory injection volume (Injection Feedback Val #1 to #4) is from -4.9 to 4.9 mm³/st.

CHECK WHETHER DTC OUTPUT RECURS (DTC P1238)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester on.
Clear the DTCs Click here.
Turn the ignition switch off for 30 seconds or more.
Start the engine.
Warm up the engine (engine coolant temperature is 75°C (167°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).
Enter the following menus: Powertrain / Engine and ECT / DTC.

Read the pending DTCs.

Tech Tips

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

Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input DTC P1238.

Check the DTC judgment result.

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

Tech Tips

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

END

REPLACE ECM
1. Replace the ECM Click here.
NEXT
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here
CHECK ENGINE TO DETERMINE CAUSE OF LOW COMPRESSION

NEXT
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here
REPAIR OR REPLACE HARNESS OR CONNECTOR
1. Repair or replace the harness or connector.
NEXT
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
1. Connect the intelligent tester to the DLC3.
2. Clear the DTCs Click here.
3. Turn the ignition switch off for 30 seconds or more.
4. Start the engine.
5. Warm up the engine (engine coolant temperature is 75°C (167°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.
  
  Tech Tips
  
  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.
NEXT
END