C18 Marine Auxiliary Engines Caterpillar

Use this procedure under the following circumstances:

• 1-11 Injector Cylinder #1 fault

• 2-11 Injector Cylinder #2 fault

• 3-11 Injector Cylinder #3 fault

• 4-11 Injector Cylinder #4 fault

• 5-11 Injector Cylinder #5 fault

• 6-11 Injector Cylinder #6 fault

• You have been directed to this procedure from Troubleshooting, "Troubleshooting without a Diagnostic Code".

Perform this procedure under conditions that are identical to the conditions that exist when the problem occurs. Typically, problems with the injector solenoid occur when the engine is warmed up and/or when the engine is under vibration (heavy loads).

The engine has electronic unit injectors that are mechanically actuated and electronically energized. The Electronic Control Module (ECM) sends a 105 volt pulse to each injector solenoid. The pulse is sent at the proper time and at the correct duration for a given engine load and speed. The solenoid is mounted on top of the fuel injector body. The 105 volt pulse can be individually cut out to aid in troubleshooting misfire problems.

If an open is detected in the solenoid circuit, a diagnostic code is generated. The ECM continues to try to fire the injector. If a short is detected, a diagnostic code is generated. The ECM will disable the solenoid circuit. The ECM will periodically enable the injector. If the short circuit remains this sequence of events will be repeated until the problem is corrected.

The injector codes must be programmed into the ECM. The injector code is a four digit number (last four digits of the serial number for the injector) that is found on each of the unit injectors. The ECM uses this number to compensate for manufacturing variations between individual injectors. If you replace any of the unit injectors, you must reprogram the code for the new injectors. Also, if you replace the ECM, you must reprogram all of the injector codes. The ECM will generate the following diagnostic code if the injector codes are not programmed:

• 268-02

For more information, refer to Troubleshooting, "Injector Code - Calibrate".

Illustration 1	g00735975
Electronic Unit Injector

Illustration 2	g00928080
Schematic

Illustration 3	g00944514
Pin locations for ECM

Test Step 1. Inspect Electrical Connectors and Wiring

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Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

1. Turn the keyswitch to the OFF/RESET position. A strong electrical shock hazard is present if the keyswitch is not turned to the OFF position.

2. Thoroughly inspect the J2/P2 ECM connector and the J300/P300 injector connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.

3. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the J300/P300 injector connector that are associated with injector solenoids.

   Refer to Illustration 3.

4. Check the ECM connector (allen head screw) for the proper torque of 6.0 N·m (55 lb in).

5. Check the J300/P300 injector connector in order to ensure the proper mating of the connector.

6. Check the harness and wiring for abrasions and for pinch points from the injectors to the ECM.

Expected Result:

All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.

Results:

• OK - Proceed to Test Step 2.

• Not OK -

  Repair: Perform the following repair:Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.

  Stop.

Test Step 2. Check for Logged Diagnostic Codes Regarding Injector Solenoids

1. Connect the electronic service tool to the service tool connector.

2. Turn the keyswitch to the ON position.

3. Monitor the "Logged Diagnostic Codes" screen on the electronic service tool.

Expected Result:

One or more of the following diagnostic codes has been logged:

• 1-11 Injector Cylinder #1 fault

• 2-11 Injector Cylinder #2 fault

• 3-11 Injector Cylinder #3 fault

• 4-11 Injector Cylinder #4 fault

• 5-11 Injector Cylinder #5 fault

• 6-11 Injector Cylinder #6 fault

Results:

• OK - There are logged diagnostic codes for the injectors. Proceed to Test Step 4.

• Not OK - There are no logged diagnostic codes for the injectors. Proceed to Test Step 3.

Test Step 3. Check the Variation of the Injectors Between Each of the Cylinders

1. Start the engine.

2. Allow the engine to warm up to normal operating temperature (approximately 77 °C (171 °F)).

3. After the engine is warmed to operating temperature, access the "Cylinder Cutout Test" by accessing the following display screens in order:
   • "Diagnostics"

   • "Diagnostic Tests"

   • "Cylinder Cutout Test"

4. Enable the cooling fan, if the fan is not controlled by the ECM. If the ECM controls the cooling fan, the cooling fan will start automatically when the test begins.

5. Shut off all parasitic loads.

6. Set the engine speed to 1200 ± 20 rpm.

7. Select the start button at the bottom of the screen for the cylinder cutout test.

8. Select the "4 Cylinder Cutout Test" which is the default test.

9. Follow the instructions that are provided in the Cylinder Cutout test. The Cylinder Cutout tests are interactive so the procedure is guided to the finish.

   Note: The "Manual Cylinder Cutout Test" is also available. Access the manual test by selecting the "Change" button on the screen for the cylinder cutout test. The "4 Cylinder Cutout Test" is the recommended starting procedure. The automated tests run twice collecting data. The two sets of data are analyzed and an "OK" or "NOT OK" result is displayed.

Expected Result:

All cylinders indicate "OK".

Results:

• OK - All cylinders indicate "OK".

  Repair: If the engine is misfiring or if the engine has low power, refer to Troubleshooting, "Engine Misfires, Runs Rough or Is Unstable" and Troubleshooting, "Low Power/Poor or No Response to Throttle".

  If a diagnostic code results from running the cylinder cutout test, proceed to Test Step 4.

• Not OK - Proceed to Test Step 4.

Test Step 4. Use the Injector Solenoid Test to Test the Injector Solenoids

1. Start the engine.

2. Allow the engine to warm up to normal operating temperature (approximately 77 °C (171 °F)).

3. Turn the keyswitch to the OFF/RESET position.

4. Turn the keyswitch to the ON position.

5. Access the "Injector Solenoid Test" on Cat ET by accessing the following display screens in order:
   • "Diagnostics"

   • "Diagnostic Tests"

   • "Injector Solenoid Test"

6. Activate the test.

   Note: The test is in the "Interactive Diagnostic Tests". Do not confuse the "Injector Solenoid Test" with the "Cylinder Cutout Test". The "Cylinder Cutout Test" is used to shut off fuel to a specific cylinder while the engine is running. The injector solenoid test is used in order to actuate the injector solenoids. This allows the click of the injector solenoids to be heard when the engine is not running in order to determine that the circuit is functioning properly.

7. As each solenoid is energized by the ECM an audible click can be heard at the valve cover. Listen for a click at each valve cover. A black square will appear over the cylinder number when the cylinder is being fired.

8. Perform the injector solenoid test at least two times.

Expected Result:

All cylinders indicate "OK".

Results:

• OK - There is not an electronic problem with the injectors at this time.

  Repair: If the "Cylinder Cutout Test" returned a "NOT OK" for any injector, refer to Troubleshooting, "Engine Misfires, Runs Rough or Is Unstable".

  Stop.

• Not OK - Note the cylinders that indicate a short in the circuit. Proceed to Test Step 5.

• Not OK - Note the cylinders that indicate an open circuit. Proceed to Test Step 6.

Test Step 5. Use the Injector Solenoid Test to Check for Shorts in the Engine Wiring Harness

Show/hide table

Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

1. Turn the keyswitch to the OFF/RESET position. A strong electrical shock hazard is present if the keyswitch is not turned to the OFF/RESET position.

2. Disconnect the J300/P300 injector connector at the valve cover base.

3. Turn the keyswitch to the ON position.

4. Perform the injector solenoid test at least two times.

Expected Result:

All cylinders indicate "OPEN".

Results:

• OK - Proceed to Test Step 10.

• Not OK - Note the cylinders that indicate a short circuit. Proceed to Test Step 7.

Test Step 6. Use the Injector Solenoid Test to Check for Opens in the Engine Wiring Harness

Illustration 4	g00706830
Engine harness connector for the injectors

Show/hide table

Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

1. Turn the keyswitch to the OFF/RESET position. A strong electrical shock hazard is present if the keyswitch is not turned to the OFF/RESET position.

2. Disconnect the J300/P300 injector connector at the valve cover base.

3. Turn the keyswitch to the ON position.

4. Fabricate a jumper wire 100 mm (4 inch) long. Crimp a Deutsch pin to both ends of the wire.

5. Insert one end of the jumper wire into the common socket of the problem injector. Insert the other end of the jumper wire into the appropriate socket for the suspect injector in the P300 injector connector. For example, if injector 5 is the problem injector, insert the jumper in terminal 5 and in terminal 8 of the P300 injector connector.

6. Perform the injector solenoid test at least two times.

7. Repeat this test for each suspect Injector. Ensure that the injector solenoid test is disabled before handling the jumper wires.

Expected Result:

Cat ET displays "SHORT" for the cylinder with the jumper wire.

Results:

• OK - Cat ET displays "SHORT" for the cylinder with the jumper wire. Proceed to Test Step 9.

• Not OK - Cat ET displays "OPEN" for the cylinder with the jumper wire. Proceed to Test Step 8.

Test Step 7. Use the Injector Solenoid Test to Check the ECM for Short Circuits

Show/hide table

Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

1. Turn the keyswitch to the OFF/RESET position. A strong electrical shock hazard is present if the keyswitch is not turned to the OFF/RESET position.

2. Disconnect the J2/P2 ECM connector from the ECM and check for evidence of moisture.

3. Turn the keyswitch to the ON position.

4. Perform the injector solenoid test at least two times.

Expected Result:

All cylinders indicate "OPEN" when the P2 ECM connector is disconnected from the ECM.

Note: When the engine harness is disconnected all of the diagnostic codes for supply voltage to the sensors will be active. This is normal. Clear all of these diagnostic codes after completing this test step.

Results:

• OK - The short circuit is in the engine harness.

  Repair: Repair the engine harness or replace the engine harness, as required. Clear all diagnostic codes after completing this test step.Verify that the repair eliminates the problem.

  Stop.

• Not OK - The ECM reads a short on the inputs for the injector harness.

  Repair: Perform the following repair:

  1. Temporarily connect a test ECM.

  2. Remove all jumpers and replace all connectors.

  3. Recheck the system for active diagnostic codes.

  4. Repeat the test step.

  5. If the problem is resolved with the test ECM, reconnect the suspect ECM.

  6. If the problem returns with the suspect ECM, replace the ECM.

  7. Verify that the repair eliminates the problem.

  Stop.

Test Step 8. Check the ECM For an Open Circuit

Show/hide table

Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

1. Turn the keyswitch to the OFF/RESET position. A strong electrical shock hazard is present if the keyswitch is not turned to the OFF/RESET position.

2. Disconnect the engine harness from the J2 ECM connector. Connect a 140-2266 Cable (Breakout T) to the ECM. Do not connect the engine harness to the Breakout T.

3. Use a jumper wire to short between the socket of the injector and the common socket of the suspect injector.

4. Turn the keyswitch to the ON position.

5. Perform the injector solenoid test at least two times.

   Note: When the engine harness is disconnected all of the diagnostic codes for supply voltage to the sensors will be active. This is normal. Clear all of these diagnostic codes after completing this test step.

Expected Result:

Cat ET displays "SHORT" for the cylinder with the jumper wire.

Results:

• OK - The ECM is okay.

  Repair: Replace the engine harness or repair the engine harness, as required.Verify that the repair eliminates the problem.

  Stop.

• Not OK -

  Repair: Perform the following repair:

  1. Temporarily connect a test ECM.

  2. Remove all jumpers and replace all connectors.

  3. Recheck the system for active diagnostic codes.

  4. Repeat the test step.

  5. If the problem is resolved with the test ECM, reconnect the suspect ECM.

  6. If the problem returns with the suspect ECM, replace the ECM.

  7. Verify that the repair eliminates the problem.

  Stop.

Test Step 9. Check The Injector Harness Under the Valve Cover for an Open Circuit

Show/hide table

Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

1. Turn the keyswitch to the OFF/RESET position. A strong electrical shock hazard is present if the keyswitch is not turned to the OFF/RESET position.

2. Reconnect the J300/P300 injector connector at the valve cover base.

3. Remove the valve cover.

4. Disconnect the harness from the problem injector. Disconnect the harness from the other injector that has the same injector common line.

5. Thoroughly clean the terminals of both injectors and of the harness.

6. Exchange the harness between the two injectors that share the common line.

7. Turn the keyswitch to the ON position.

8. Perform the injector solenoid test at least two times.

Expected Result:

Exchanging the harness between the two injectors caused the problem to move to the other injector on Cat ET.

Results:

• OK - Cat ET indicates that the problem has moved.

  Repair: Replace the injector harness under the valve cover.Verify that the repair eliminates the problem.

  Stop.

• Not OK - Cat ET still indicates that the problem is with the original injector.

  Repair: Replace the faulty injector. Restore the wiring to the proper injectors.Verify that the repair eliminates the problem.

  Stop.

Test Step 10. Check the Engine Harness Under the Valve Cover for Short Circuits in the Injector Wires

Show/hide table

Electrical shock hazard. The electronic unit injector system uses 90-120 volts.

1. Turn the keyswitch to the OFF/RESET position. A strong electrical shock hazard is present if the keyswitch is not turned to the OFF/RESET position.

2. Remove the valve cover.

3. Reconnect the J300/P300 injector connector at the valve cover base.

4. Disconnect each of the injectors that indicate a "SHORT" from the wiring harness. Ensure that each of the connectors from the disconnected injector harness does not touch other components and short to ground.

5. Turn the keyswitch to the ON position.

6. Perform the injector solenoid test at least two times.

Expected Result:

The cylinder indicates an "OPEN" circuit.

Results:

• OK - Neither of the injector wires are shorted to the engine.

  Repair: Replace the Injector.

  Stop.

• Not OK - There is a short in the injector harness under the valve cover.

  Repair: Replace the injector harness under the valve cover.Verify that the repair eliminates the problem.

  Stop.