Electronic Modular Control Panel II (EMCP II) Caterpillar

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System Schematic For Starting Motor Relay (SMR) On 3306B And 3406C Powered Generators

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System Schematic For Fuel Control Relay On ETR Systems On 3306B And 3406C Powered Generators

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System Schematic For Starting Motor Relay (SMR) On 3500 Engines And 3412C Engines

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System Schematic For Fuel Control Relay On ETR Systems On 3500 Engines And 3412C Engines

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System Schematic For Starting Motor Relay On EUI Engines ( 3500B Series)

In order to find the cause of an overcrank shutdown, perform the following procedure.

Test Step 1. PERFORM THE INITIAL CHECK.

1. Check for active diagnostic codes (with the exception of the CID 566 FMI 7 code). Check for other flashing indicators on the GSC. If any codes are present, correct the diagnostic codes first. Go to the appropriate procedure for that fault.

Expected Result:

No other diagnostic codes or indicators are active.

Results:

• OK - No other diagnostic codes or indicators are active. Proceed to Test Step 2.

• NOT OK - Another diagnostic code is active or an indicator is active.

  Repair: Exit this procedure. Troubleshoot the active code or indicator.

  Stop.

Test Step 2. INSPECT THE FUEL AND AIR SUPPLY.

1. Check the fuel level and quality. Refer to the Engine Service Manual.

2. Check for a plugged fuel filter. Refer to the Engine Service Manual.

3. Check for a plugged air filter. Refer to the Engine Service Manual.

Expected Result:

The air and fuel systems are within specifications.

Results:

• OK - The air and fuel systems are within specifications. Proceed to Test Step 4.

• NOT OK - One or more of the items in this Test Step are NOT within specifications.

  Repair: Correct the problem with the corresponding system. Reset the genset. Operate the genset and verify that the problem has been corrected.

  Stop.

Test Step 3. AIR SHUTOFF SOLENOID INSTALLATION CHECK.

1. Check the engine for the air shutoff solenoid.

Expected Result:

The engine has the air shutoff solenoid.

Results:

• OK - The engine has the air shutoff solenoid. Proceed to Test Step 4.

• NOT OK - The engine does NOT have the air shutoff solenoid. Proceed to Test Step A.

Test Step 4. AIR SHUTOFF SOLENOID INSTALLATION CHECK.

1. Check the air shutoff solenoid for activation. The solenoid must be deactivated in order for the engine to start. See Testing And Adjusting, "Air Shutoff Solenoid - Check".

Results:

Continue to the next test step.

Test Step 5. CHECK THE AIR SHUTOFF SOLENOID.

1. Check the engine starting system. Check the fuel system. In order to check the fuel control solenoid, see Testing And Adjusting, "CID 566 FMI 7 Unexpected Shutdown Improper Mechanical Response - Test". Check for a fault with the engine starting system or the fuel system.

Expected Result:

The air shutoff solenoid is working properly.

Results:

• OK - The air shutoff solenoid is working properly. Proceed to Test Step 6.

• NOT OK - The air shutoff solenoid is NOT working properly.

  Repair: Correct the problem with the air shutoff solenoid. Reset the genset. Operate the genset and verify that the problem has been corrected.

  Stop.

Test Step 6. CHECK THE FUSES.

1. Check the fuses "F2" and "F4" on the relay module.

Expected Result:

The fuse is NOT blown.

Results:

• OK - The fuse is NOT blown. Proceed to Test Step 7.

• NOT OK - The fuse is blown. Proceed to Test Step 15.

Test Step 7. CHECK THE SETPOINTS.

1. View the setpoints P17 (total cycle crank time) and P18 (cycle crank time). Make a note of the setpoints. See System Operation, "Engine/Generator Setpoint Viewing OP2-0". Compare the setpoints against the default setpoints of the particular generator set.

Expected Result:

The setpoints are correct. The factory default values are 90 seconds for P17 and 10 seconds for P18. Engines that are equipped with prelube pumps may require cycle crank times (setpoint P18) of 30 seconds or more.

Results:

• OK - The setpoints are correct. Proceed to Test Step 8.

• NOT OK - The setpoints are NOT correct.

  Repair: Reprogram the setpoints. Reset the genset. Operate the genset and verify that the problem has been corrected.

  Stop.

Test Step 8. CHECK THE BATTERY VOLTAGE.

1. The engine should be off.

2. Measure the system voltage at the battery.

Expected Result:

For 24 volt systems, the voltage should be from 24.8 to 29.5 DCV. For 32 volt systems, the voltage should be from 33.1 to 39.3 DCV.

Results:

• OK - The voltage is correct. Proceed to Test Step 9.

• NOT OK - The battery voltage is NOT within specifications.

  Repair: Further testing of the battery system is necessary. See Testing And Adjusting, "CID 168 Electrical System".

  Stop.

Test Step 9. CHECK THE ENGINE STARTING FUNCTION.

Note: The GSC is attempting to crank whenever the K4 indicator is ON. The K4 indicator is located on the lower display. Be aware of the 10 second crank cycle (set by P18)that is factory set. Be sure that the K4 indicator is ON while you are making the following measurements. More than one start may be required to complete this test.

1. Disconnect the "B+" wire on the pinion solenoid of the starting motor. Do not allow the "B+" wire connection to contact the frame or other metal components. The "B+" wire remains disconnected for all of the remaining steps of this procedure.

2. Turn the engine control switch (ECS) to OFF/RESET and then turn the switch to START.

3. Measure the voltage from the B+ Pinion Solenoid wire (currently disconnected from the starting motor) to "B-" (ground) while the K4 indicator is ON.

Expected Result:

The voltage should be within ±2.0 DCV of the battery voltage.

Results:

• OK - The voltage is within ±2.0 DCV of the battery voltage. The voltage is correct.

  Repair: The starter motor has failed. Repair the starting motor or replace the starting motor. Verify that the new starter motor corrects the problem. Refer to the Engine Service Manual or Starting Motor Service Manual.

  Stop.

• NOT OK - The voltage is NOT correct. Proceed to Test Step 10.

Test Step 10. CHECK THE SMMS.

1. Disconnect the "B+" wire on the pinion solenoid of the starting motor. The "B+" wire remains disconnected for all of the remaining steps of this procedure.

2. Turn the ECS to OFF/RESET and then turn the switch to START.

3. In the junction box, measure the DC voltage from "B-" (ground) to the output terminal of starting motor magnetic switch (SMMS).

Expected Result:

The voltage should be within ±2.0 DCV of the battery voltage.

Results:

• OK - The voltage is within ±2.0 DCV of the battery voltage. Proceed to Test Step 11.

• NOT OK - The voltage is not within specifications.

  Repair: The engine wire harness is faulty. Repair the engine wire harness or replace the engine wire harness. See the Generator Set Wiring Diagram in Testing And Adjusting, "Schematics And Wiring Diagrams".

  Stop.

Test Step 11. CHECK THE VOLTAGE AT THE CONTROL PANEL.

1. Disconnect the "B+" wire on the pinion solenoid of the starting motor. The "B+" wire remains disconnected for all of the remaining steps of this procedure.

2. Prepare to make a voltage measurement at the DC connector 2. Use the 7x-1710 Cable Probes. DO NOT disconnect DC connector 2. DC connector 2 is the left most connector when viewed from the front panel.

3. From within the control panel, prepare to measure the DC voltage from "B-" (ground) to connector contact 6 of DC connector 2. Use the 7X-1710 Cable Probes .

4. Turn the ECS to OFF/RESET and then turn the switch to START. Measure the voltage.

Expected Result:

The voltage should be within ±2.0 DCV of the battery voltage.

Results:

• OK - The voltage is within ±2.0 DCV of the battery voltage.

  Repair: The engine wire harness is faulty. Repair the engine wire harness or replace the engine wire harness. See Generator Set Wiring Diagram in the Testing And Adjusting, "Schematics And Wiring Diagrams".

  Stop.

• NOT OK - The voltage was not within specifications. Proceed to Test Step 12.

Test Step 12. CHECK THE VOLTAGE AT RM-18.

1. The "B+" wire on the pinion solenoid of the starting motor remains disconnected.

2. Turn the ECS to OFF/RESET and then turn the switch to START.

3. Measure the DC voltage from RM-18 of the relay module to "B-" (ground) while the K4 indicator is ON.

Expected Result:

The voltage should be within ±2.0 DCV of the battery voltage.

Results:

• OK - The voltage is within ±2.0 DCV of the battery voltage. The voltage is correct.

  Repair: The emergency stop push button (ESPB) or the related wiring is faulty. Troubleshoot the ESPB and the related wiring. See the Generator Set Wiring Diagram in Testing And Adjusting, "Schematics And Wiring Diagrams".

  Stop.

• NOT OK - The voltage was not correct. Proceed to Test Step 13.

Test Step 13. CHECK THE VOLTAGE AT RM-6.

1. The "B+" wire on the pinion solenoid of the starting motor remains disconnected.

2. Turn the ECS to OFF/RESET and then turn the switch to START.

3. Measure the DC voltage from RM-6 of the relay module to "B-" (ground) while the K4 indicator is ON.

Expected Result:

The voltage should be within ±2.0 DCV of the battery voltage.

Results:

• OK - The voltage is within ±2.0 DCV of the battery voltage.

  Repair: The relay module is faulty. Replace the relay module. First, make sure that the K4 indicator is ON. See Testing And Adjusting, "Relay Module - Replace".

  Stop.

• NOT OK - The voltage was not correct. Proceed to Test Step 14.

Test Step 14. CHECK THE VOLTAGE AT RM-33.

1. The "B+" wire on the pinion solenoid of the starting motor remains disconnected.

2. Turn the ECS to OFF/RESET and then turn the switch to START.

3. Measure the DC voltage from RM-33 of the relay module to "B-" (ground) while the K4 indicator is ON.

Expected Result:

The voltage should be within ±2.0 DCV of the battery voltage.

Results:

• OK - The voltage is within ±2.0 DCV of the battery voltage. The fuse "F4" is blown. Proceed to Test Step 15.

• NOT OK - The voltage is not correct.

  Repair: The "B+" terminal or the wiring to RM-33 is faulty. Repair the wiring or replace the wiring. See the Generator Set Wiring Diagram in Testing And Adjusting, "Schematics And Wiring Diagrams".

  Stop.

Test Step 15. TROUBLESHOOT BLOWN FUSE.

1. Remove fuse "F4" from the relay module.

2. At the relay module, measure the resistance from "B-" (ground) to RM-18 (MUI Engines) or RM-5 (EUI Engines).

3. For fuse "F2", measure the resistance from "B-" (ground) to RM-15 (MUI Engines) or RM-4 (EUI Engines).

Expected Result:

The resistance measures greater than 5 Ohms.

Results:

• OK - Resistance is greater than 5 ohms. The fuse is not blown.

  Repair: Carefully check ALL wires that are connected to the appropriate terminal of the relay module for abrasion or worn spots in the insulation that could be causing the short. Check the wires in the generator panel. Check the wires in the engine harness. Refer to the appropriate wiring diagrams for the circuit that is being checked. Repair the wiring or replace the wiring.

  Stop.

• NOT OK - Resistance is approximately 5 ohms or less.

  Repair: There is a short to ground. See the Generator Set Wiring Diagram in Testing And Adjusting, "Schematics And Wiring Diagrams". Remove one component or wire at a time that is in series with RM-18 until the failed component or wire is isolated. Replace the component or wiring that has failed.

  Stop.