3512B Petroleum Engines with the ADEM 2 Electronic Control Module Caterpillar

The engine has Fuel 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 of CID FMI 1-05 to 12-05 is generated. The ECM continues to try to fire the injector. If a short is detected, a diagnostic code of CID FMI 1-06 to 12-06 is generated. The ECM will disable the solenoid circuit. The ECM will then enable the solenoid. If the short circuit remains this sequence of events will be repeated until the problem is corrected.

Illustration 1	g00821245

Test Step 1. Check for Connector Damage.

1. Turn the engine control to the OFF position.

2. Thoroughly inspect the ECM connector J1/P1. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.

3. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.

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

5. Check the customer connector (allen head screw) for the proper torque of 2.25 ± 0.25 N·m (20 ± 2 lb in).

6. Check the harness and the wiring for abrasion and pinch points.

Expected Result:

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

Results:

• OK - The wiring and connectors are okay. Proceed to test step 2.

• Not OK - The connectors and/or wiring need repair.

  Repair: Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

Test Step 2. Check for "LOGGED" Diagnostic Codes.

1. Turn the engine control to the OFF position.

2. Start the Caterpillar Electronic Technician (ET).

3. Turn the engine control to the ON position.

4. Observe the display diagnostics screen on the Cat ET.

Expected Result:

A CID-FMI 1-05 to 12-05 or 1-06 to 12-06 should not be logged.

Results:

• OK - There are no logged diagnostic codes. Proceed to test step 3.

• Not OK - There are logged diagnostic codes. Proceed to test step 4.

Test Step 3. Perform the Injector Solenoid Test.

Note: The test verifies that the ECM can fire the solenoids. Do not try to crank the engine during this test. The engine will start and the ECM will terminate the Injector Solenoid Test.

1. Start the Cat ET.

2. Turn the engine control to the ON position.

3. Use the diagnostic tests on the Cat ET to initiate the injector solenoid test.

4. Listen for a click at each valve cover. A black square will appear over the cylinder number when the cylinder is being fired.

5. Repeat the test a few times. Verify that the ECM is energizing each solenoid.

Expected Result:

As each solenoid is energized by the ECM, an audible click of the solenoid should be heard. The solenoids will be energized one at a time in the following numerical order: 1-12. There will be momentary delay between each one.

Results:

• OK - An audible click of the solenoid was heard for each solenoid. Proceed to test step 5.

• Not OK - An audible click of the solenoid was not heard for each solenoid. Proceed to test step 4.

Test Step 4. Check for an Open Circuit in the Wiring Harness.

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This engine uses high voltage to control the fuel injectors. Disconnect electronic fuel injector enable circuit connector to prevent personal injury. Do not come in contact with the fuel injector terminals while the engine is running.

1. Turn the engine control to the OFF position.

2. Disconnect the ECM connector J2/P2.

3. Measure the resistance between the solenoid wire pairs at the ECM connector P2.

   Measure the resistance for SOLENOID 1 at P2-16 and P2-5.

   Measure the resistance for SOLENOID 2 at P2-40 and P2-11.

   Measure the resistance for SOLENOID 3 at P2-26 and P2-5.

   Measure the resistance for SOLENOID 4 at P2-34 and P2-11.

   Measure the resistance for SOLENOID 5 at P2-32 and P2-17.

   Measure the resistance for SOLENOID 6 at P2-28 and P2-21.

   Measure the resistance for SOLENOID 7 at P2-38 and P2-17.

   Measure the resistance for SOLENOID 8 at P2-22 and P2-21.

   Measure the resistance for SOLENOID 9 at P2-37 and P2-27.

   Measure the resistance for SOLENOID 10 at P2-18 and P2-33.

   Measure the resistance for SOLENOID 11 at P2-31 and P2-27.

   Measure the resistance for SOLENOID 12 at P2-12 and P2-33.

Expected Result:

The resistance should be between 0.6 and 3.6 Ohms for each measurement with the injectors connected.

Results:

• OK - The resistance is between 0.6 and 3.6 Ohms for each measurement. Proceed to test step 6.

• Not OK - The resistance is greater than 3.6 Ohms. There is an open in the harness or in an injector solenoid. Proceed to test step 7.

Test Step 5. Perform the Cylinder Cutout Test.

Note: This test will help the Service Technician verify a fuel delivery or a starvation problem when no diagnostic code is present.

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NOTICE
Engine power is reduced when a properly functioning cylinder is cut out. Make sure that you will not damage auxiliary or driven equipment if the engine power changes suddenly.

1. Start the Cat ET.

2. Start the engine. Apply a constant load to the engine.

3. Use the Cat ET to cut out a single solenoid.

4. Check for a difference in the sound, feel, or power of the engine as each cylinder is cut out. The amount of change should be similar for all of the good cylinders. The amount of change should be minimal for a weak cylinder or a bad cylinder.

5. Disable the override. Repeat this step for each of the solenoids.

Expected Result:

The amount of change should be similar for all of the good cylinders. The amount of change should be minimal for a weak cylinder or a bad cylinder.

Results:

• OK - There was a noticeable change in engine performance during the Cylinder Cutout Test.

  Repair: The injectors are operating correctly.

  STOP

• Not OK - There was no noticeable change in engine performance during the Cylinder Cutout Test.

  Repair: Remove the valve cover and check the injector and valve lash setting for damage or misadjustment. If no repair is required, replace the injector. Refer to System Operation, Testing And Adjusting.

  STOP

Test Step 6. Check for a Short Circuit in the Wiring Harness.

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Personal injury can result from high voltage. The Electronic Control Module produces high voltage. Make sure the Electronic Control Module is not powered and the fuel injector solenoids are disconnected before proceeding.

1. Disconnect the injector connectors J4 through J15 for the injector solenoids.

2. Measure the resistance between the solenoid wire pairs from ECM connector P2.

   Measure the resistance for SOLENOID 1 at P2-16 and P2-5.

   Measure the resistance for SOLENOID 2 at P2-40 and P2-11.

   Measure the resistance for SOLENOID 3 at P2-26 and P2-5.

   Measure the resistance for SOLENOID 4 at P2-34 and P2-11.

   Measure the resistance for SOLENOID 5 at P2-32 and P2-17.

   Measure the resistance for SOLENOID 6 at P2-28 and P2-21.

   Measure the resistance for SOLENOID 7 at P2-38 and P2-17.

   Measure the resistance for SOLENOID 8 at P2-22 and P2-21.

   Measure the resistance for SOLENOID 9 at P2-37 and P2-27.

   Measure the resistance for SOLENOID 10 at P2-18 and P2-33.

   Measure the resistance for SOLENOID 11 at P2-31 and P2-27.

   Measure the resistance for SOLENOID 12 at P2-12 and P2-33.

3. Reconnect all connectors.

Expected Result:

The resistance should be greater than 20,000 Ohms for each measurement.

Results:

• OK - The resistance is greater than 20,000 Ohms for each measurement. Proceed to test step 8.

• Not OK - The resistance is less than 20,000 Ohms for each measurement. There is a short in the harness or connectors.

  Repair: Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

Test Step 7. Isolate the Circuit.

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Personal injury can result from high voltage. The Electronic Control Module produces high voltage. Make sure the Electronic Control Module is not powered and the fuel injector solenoids are disconnected before proceeding.

1. Disconnect the suspect injector at the valve cover base.

2. Measure the resistance of the injector solenoid at the base of the valve cover.

Expected Result:

The resistance should be between 0.6 and 3.6 Ohms for each measurement.

Results:

• OK - The resistance is between 0.6 and 3.6 Ohms for each measurement. There is an open circuit or excessive resistance in the harness or connectors between the ECM and the injector connector.

  Repair: Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

• Not OK - The resistance measures more than 3.6 Ohms. There is an open circuit under the valve cover base. Proceed to test step 9.

Test Step 8. Check the Resistance of the Solenoid at the Valve Cover Base.

1. Turn the engine control to the OFF position.

2. Disconnect the solenoid connectors J4 through J15.

3. Measure the solenoid resistance between pin-1 and pin-2 at the solenoid connectors.

4. Record the measured resistances of each pair of pins.

Expected Result:

The resistance should be between 0.6 and 3.6 Ohms for each measurement.

Results:

• OK - The resistance is between 0.6 and 3.6 Ohms for each measurement. Reconnect the ECM connector P2. Reconnect the solenoid connectors. Repeat the Injector Solenoid Test. If the problem still exists, the ECM has a faulty injector driver.

  Repair: Replace the ECM. Refer to the diagnostic procedure Troubleshooting, "Replacing the ECM" BEFORE replacing the ECM.

  STOP

• Not OK - The measured resistance is more than 3.6 Ohms, or less than 0.6 Ohms. There is a problem with the valve cover harness or the injector solenoid. Proceed to test step 9.

Test Step 9. Check the Resistance of the Injector Solenoid at the Solenoid.

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This engine uses high voltage to control the fuel injectors. Disconnect the fuel enable circuit connector to prevent personal injury. Do not come in contact with the fuel injector terminals while the engine is running.

1. Turn the engine control to the OFF position.

2. Remove the valve cover of the suspect cylinder.

3. Remove the harness yoke from the solenoid terminals.

4. Measure the resistance between the two solenoid terminals on top of the suspect injector. Record the resistance.

5. Measure the resistance from either solenoid terminal to the injector. Record the resistance.

Expected Result:

Resistance between solenoid terminals should be between 0.6 and 3.6 Ohms. The normal resistance is 2.1 Ohms. The resistance from either solenoid terminal to the fuel injector body should be greater than 20,000 Ohms.

Results:

• OK - The injector solenoid is electrically okay but there is a problem in the valve cover base harness.

  Repair: Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

• Not OK - The injector has failed.

  Repair: Replace the faulty injector. Reconnect the harness yoke to the solenoid terminals. Recheck solenoid resistance at valve cover base. Verify that the harness is okay.

  STOP