3408E and 3412E Engines for the 844 Wheel Dozer and for 988F Series II and 990 Series II Wheel Loaders Ether Starting Aid - Test Caterpillar

System Operation Description:

Before testing of the ether injection system, remove the ether cylinder from the system.

Use this procedure in order to troubleshoot the ether system or use this procedure if any one of the diagnostic codes in Table 1 is active or easily repeated.

The ether injection system is used to improve the cold weather starting capability of the engine. The ECM controls the ether injection system. The ether injection system has two operating modes. The ether injection system can operate in automatic mode and in manual mode.

In the automatic mode, the ECM energizes the relay for the ether in cycles of six seconds. The ether is turned ON for three seconds. The ether is then turned OFF for three seconds.

In the automatic mode, the ether injection system is enabled when all of the following conditions occur:

• "Ether" is programmed to "Enabled" in the configuration screen.

• Engine oil temperature is less than 0 °C (32 °F).

• Engine speed is below 500 rpm.

Manual mode is activated by pressing the starting aid switch. In the manual mode, a single shot of ether is injected when the ether switch is actuated. The quantity of ether that is injected is controlled by the ECM. In the manual mode, the ether injection system is enabled when all of the following conditions are satisfied:

• The starting aid switch is placed in the MANUAL position.

• Engine speed is less than 1200 rpm.

• Engine oil temperature is less than 10 °C (50 °F).

Illustration 1	g01837273
Schematic for the ether system

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Breathing ether vapors or repeated contact of ether with skin can cause personal injury. Personal injury may occur from failure to adhere to the following procedures. Use ether only in well ventilated areas. Do not smoke while changing ether cylinders. Use ether with care to avoid fires. Do not store replacement ether cylinders in living areas or in the operator's compartment. Do not store ether cylinders in direct sunlight or at temperatures above 49 °C (120 °F). Discard cylinders in a safe place. Do not puncture or burn cylinders. Keep ether cylinders out of the reach of unauthorized personnel.

Test Step 1. Inspect Electrical Connectors and Wiring

1. Remove electrical power from the ECM.

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Illustration 2	g01139425
ECM (1) J1/P1 connectors (2) J2/P2 connectors

2. Thoroughly inspect connectors (1) and (2). Thoroughly inspect the circuit that is associated with the starting aid. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.

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Illustration 3	g01393998
P1 ECM connector (P1-25) Starting aid switch (P1-29) Return (P1-40) Ether start valve

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

4. Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.

5. Check the harness and the wiring for abrasion and for pinch points from the ether injection solenoid to the ECM. Verify that all connections and grounds are tight and free of corrosion.

Expected Result:

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

Results:

• OK - The connectors and wiring appear to be OK. Proceed to Test Step 2.

• Not OK - The connectors and/or wiring are not OK.

  Repair: Repair the circuit.Verify that the repair eliminates the problem.

  STOP

Test Step 2. Check the Starting Aid Switch Status

1. Connect the AVSpare Electronic Technician (ET) to the service tool connector.

2. Restore electrical power to the ECM.

3. Press the starting aid switch to "Manual". Observe the "Starting Aid Switch Status" on Cat ET.

Expected Result:

When the starting aid switch is pressed, Cat ET displays the status of the starting aid switch as "On".

When the starting aid switch is not pressed, Cat ET ET displays the status of the starting aid switch as "Off".

Results:

• OK - The starting aid switch is operating correctly. Proceed to Test Step 6.

• Not OK - The ECM is not reading the input from the starting aid switch. Proceed to Test Step 3.

Test Step 3. Short the Switch Wires

1. Remove electrical power from the ECM.

2. Remove the wires from the starting aid switch.

3. Restore electrical power to the ECM.

4. Create a short with the wires from the starting aid switch.

5. Return the wiring to the original configuration.

Expected Result:

When the wires are shorted, Cat ET displays the status of the starting aid switch as "On".

When the wires are not shorted, Cat ET displays the status of the starting aid switch as "Off".

Results:

• OK - The ECM is receiving the correct switch input. There is a problem with the switch.

  Repair: Replace the starting aid switch.Verify that the repair eliminates the problem.

  STOP

• Not OK - The ECM is not receiving the correct switch input. Proceed to Test Step 4.

Test Step 4. Short the Switch Inputs at the ECM

1. Remove electrical power from the ECM.

2. Disconnect the J1/P1 ECM connector.

3. Fabricate two jumper wires that are long enough to create a short between the two terminal of the ECM connector. Crimp connector sockets to one end of each of the jumper wires.

4. Remove the wire from terminal location P1-25 (starting aid switch) at the ECM connector. Install one of the jumper wires into this terminal location.

5. Remove the wire from terminal location P1-29 (return) at the ECM connector. Install one of the jumper wires into this terminal location.

6. Connect the J1/P1 ECM connector.

7. Short the jumper wires in terminals P1-25 (starting aid switch) and P1-29 (return).

8. Restore electrical power to the ECM.

9. Observe the results on the "Status" screen of Cat ET.

10. Remove electrical power from the ECM.

11. Remove the jumper wires.

Expected Result:

When the wires are shorted, Cat ET displays the status of the starting aid switch as "On".

When the wires are not shorted, Cat ET displays the status of the starting aid switch as "Off".

Results:

• OK - The ECM is reading the switch input properly. There may be a problem in the wiring between the switch and the ECM. Proceed to Test Step 5.

• Not OK - The ECM is not reading the switch input properly.

  Repair: Replace the ECM. Refer to Troubleshooting, "ECM - Replace" before replacing the ECM.Verify that the repair eliminates the problem.

  STOP

Test Step 5. Check the Wiring Harness from the Starting Aid Switch to the ECM

1. Verify that the electrical power is removed from the ECM.

2. Disconnect the J1/P1 ECM connector.

3. Short the wires from the starting aid switch on the J1/P1 connector.

4. Disconnect the connector for the starting aid switch.

5. Measure the resistance between the terminals at the starting aid switch.

6. Return the wiring to the original configuration.

Expected Result:

The resistance does not indicate an open circuit.

Results:

• OK - The resistance does not indicate an open circuit. Proceed to Test Step 6.

• Not OK - The resistance indicates an open circuit. There is a problem in the harness between the starting aid switch and the ECM.

  Repair: Repair the circuit.Verify that the repair eliminates the problem.

  STOP

Test Step 6. Check the Resistance of the Ether Control Relay

1. Verify that there is no electrical power at the ECM.

2. Measure the resistance across terminal 85 (return) and terminal 86 (ether start).

Expected Result:

The resistance is between 250 Ohms and 500 Ohms.

Results:

• OK - The resistance is between 250 Ohms and 500 Ohms. Proceed to Test Step 7.

• Not OK - The resistance is not between 250 Ohms and 500 Ohms. The relay is faulty.

  Repair: Replace the relay.Verify that the repair eliminates the problem.

  STOP

Test Step 7. Check the Voltage at the Ether Relay

1. Restore electrical power to the ECM.

2. Proceed to the "Diagnostic Override Screen" in Cat ET.

3. Activate the ether injection system.

   Note: The diagnostic override will only activate the ether relay for three seconds.

4. Measure the voltage across terminal 85 (digital return) and chassis ground.

Expected Result:

The voltage is 24.0 ± 8.0 VDC.

Results:

• OK - The voltage is 24.0 ± 8.0 VDC. Proceed to Test Step 10.

• Not OK - The voltage is not 24.0 ± 8.0 VDC. Proceed to Test Step 8.

Test Step 8. Check the Wiring Harness from the Ether Relay to the ECM

1. Remove electrical power from the ECM.

2. Disconnect the J1/P1 ECM connector.

3. Remove the wire from terminal location P1-40 (ether start valve) at the ECM connector.

4. Reconnect the J1/P1 ECM connector.

5. Remove the wire from terminal location 86 (ether start) at the ether relay.

6. Measure the resistance of the wire.

7. Return the wiring at the ether relay to the original configuration.

Expected Result:

The resistance does not indicate an open circuit.

Results:

• OK - The resistance does not indicate an open circuit. Proceed to Test Step 9.

• Not OK - The resistance indicates an open circuit. There is a problem in the harness between the ether relay and the ECM.

  Repair: Repair the circuit.Verify that the repair eliminates the problem.

  STOP

Test Step 9. Check the Voltage for the Ether Relay at the ECM

1. Verify that the electrical power is removed from the ECM.

2. Install a jumper wire into the terminal location P1-40 (ether start valve) at the ECM connector.

3. Connect the J1/P1 ECM connector.

4. Restore electrical power to the ECM.

5. Proceed to the "Diagnostic Override Screen" in Cat ET.

6. Activate the ether injection system.

   Note: The diagnostic override will only activate the ether relay for three seconds.

7. Measure the voltage between the jumper wire in P1-40 (ether start valve) and chassis ground.

8. Remove electrical power from the ECM.

9. Return the wiring to the original configuration.

Expected Result:

The voltage is 24.0 ± 8.0 VDC.

Results:

• OK - The voltage is 24.0 ± 8.0 VDC. The ECM is supplying the correct voltage. Proceed to Test Step 10.

• Not OK - The voltage is not 24.0 ± 8.0 VDC. The ECM is not supplying the correct voltage.

  Repair: Replace the ECM. Refer to Troubleshooting, "ECM - Replace" before replacing the ECM.Verify that the repair eliminates the problem.

  STOP

Test Step 10. Check the Power Supply to the Ether Relay

1. Restore electrical power to the ECM.

2. Measure the voltage across terminal 30 (+Battery) on the ether control relay and chassis ground.

Expected Result:

The voltage is 24.0 ± 8.0 VDC.

Results:

• OK - The voltage is 24.0 ± 8.0 VDC. Proceed to Test Step 11.

• Not OK - The voltage is not 24.0 ± 8.0 VDC. There is a problem in the wiring between the ether relay and the +Battery.

  Repair: Repair the circuit.Verify that the repair eliminates the problem.

  STOP

Test Step 11. Check the Output Voltage of the Ether Relay

1. Verify that there is electrical power to the ECM.

2. Proceed to the "Diagnostic Override Screen" in Cat ET.

3. Activate the ether injection system.

   Note: The diagnostic override will only activate the ether relay for three seconds.

4. Measure the voltage across terminal 87 (+Battery) of the ether relay and chassis ground.

Expected Result:

The voltage is 24.0 ± 8.0 VDC.

Results:

• OK - The voltage is 24.0 ± 8.0 VDC. Proceed to Test Step 12.

• Not OK - The voltage is not 24.0 ± 8.0 VDC. There is a problem with the relay.

  Repair: Replace the relay.Verify that the repair eliminates the problem.

  STOP

Test Step 12. Check the Wiring Harness from the Ether Relay to the Ether Solenoid

1. Remove electrical power from the ECM.

2. Disconnect the connector for the ether solenoid.

3. Restore electrical power to the ECM.

4. Proceed to the "Diagnostic Override Screen" in Cat ET.

5. Activate the ether injection system.

   Note: The diagnostic override will only activate the ether relay for three seconds.

6. Measure the voltage between terminal location 1 on the connector for the ether solenoid and chassis ground.

7. Remove electrical power from the ECM.

8. Return the wiring to the original configuration.

Expected Result:

The voltage is 24.0 ± 8.0 VDC.

Results:

• OK - The voltage is 24.0 ± 8.0 VDC. Proceed to Test Step 13.

• Not OK - The voltage is not 24.0 ± 8.0 VDC. There is a problem with the harness.

  Repair: Repair the circuit .Verify that the repair eliminates the problem.

  STOP

Test Step 13. Check for Correct Operation of the Ether Solenoid

1. Restore electrical power to the ECM.

2. Proceed to the "Diagnostic Override Screen" in Cat ET.

3. Activate the ether injection system.

   Note: The diagnostic override will only activate the ether relay for three seconds.

4. Listen for an audible click as the ether solenoid is activated. Listen for an audible click as the ether solenoid is deactivated.

Expected Result:

A click is heard.

Results:

• OK - A click is heard. The ether injection system is operating correctly.

  Repair: There may be an intermittent problem. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.

  STOP

• Not OK - A click is not heard. Proceed to Test Step 14.

Test Step 14. Check the Return Wire of the Ether Solenoid

1. Remove electrical power from the ECM.

2. Measure the resistance between terminal 2 (return) and chassis ground.

Expected Result:

The resistance does not indicate an open circuit.

Results:

• OK - The resistance does not indicate an open circuit. The ether solenoid is faulty.

  Repair: Replace the ether solenoid.Verify that the repair eliminates the problem.

  STOP

• Not OK - The resistance indicates an open circuit. There is a problem in the harness.

  Repair: Repair the harness.Verify that the repair eliminates the problem.

  STOP