C-12 Generator Set Engine Caterpillar

Use this procedure to troubleshoot any suspect problems with the ether system.

This procedure covers the following diagnostic codes:

• 545-05 Ether Start Relay open/short to +batt

• 545-06 Ether Start Relay short to ground

The ether injection system will improve cold weather starting of the engine. The engine's Electronic Control Module (ECM) controls the ether injection system. The ether injection system is disabled if there is an active engine shutdown.

The ECM energizes the ether relay for a predetermined amount of time that is based on the coolant temperature and the inlet manifold air temperature.

The ether injection system is enabled when all of the following conditions occur:

• Ether is enabled in the system configuration parameters.

• Engine speed is less than 35 rpm.

• Coolant temperature or inlet manifold air temperature is less than 0 °C (32 °F).

A test on the Caterpillar Electronic Technician (ET) allows the technician to activate the ether system. The test is functional when the engine speed is 0 rpm. The test can be activated by selecting the "Override Parameters" screen on Cat ET.

Illustration 1	g01196969
Schematic

Illustration 2	g01196975
P1 ECM connector (P1-21) Ether relay

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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. To avoid possible injury, be sure the brakes are applied and all controls are in Hold or Neutral when starting the engine.

Test Step 1. Inspect Electrical Connectors and Wiring

1. Remove electrical power from the ECM.

2. Thoroughly inspect the ECM connector J1/P1. Inspect all of the other connectors for the circuit. 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 that are associated with the circuit.

4. Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.

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

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 - The harness and wiring are OK. If diagnostic codes for the ether circuit are active, proceed to Test Step 2. If the ether circuit is not injecting ether, verify that the ether canister is not empty. If the ether canister is not empty, proceed to Test Step 6.

• Not OK - There is a problem in the connectors and/or wiring.

  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 Active Diagnostic Codes

Note: The ether canister must be removed prior to activating this test.

1. Restore electrical power to the ECM.

2. Connect Caterpillar Electronic Technician (ET) to the service tool connector.

3. Proceed to the "Diagnostic Overrides" screen on Cat ET.

4. Activate the ether injection system. The diagnostic override will activate for ten seconds.

5. Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.

6. Determine if the problem is related to a 05 diagnostic code or a 06 diagnostic code.

Expected Result:

No diagnostic codes are active.

Results:

• OK - No diagnostic codes are active.

  Repair: The ether system injected ether. The problem may be intermittent. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect" for information on inspecting connectors and wiring.

  STOP

• Not OK - A 06 diagnostic code is active at this time. Proceed to Test Step 3.

• Not OK - A 05 diagnostic code is active at this time. Proceed to Test Step 4.

Test Step 3. Create an Open at the Ether Relay

1. Remove electrical power from the ECM.

2. Disconnect the wire to the coil of the ether relay from ECM connector P1-21.

3. Restore electrical power to the ECM.

4. Proceed to the "Diagnostic Overrides" screen on Cat ET.

5. Activate the ether injection system. The diagnostic override will activate for ten seconds.

   Note: Monitor the "Active Diagnostic Codes" screen on Cat ET.

6. Check for an active 05 diagnostic code for the ether circuit.

7. Remove electrical power from the ECM.

Expected Result:

A 05 diagnostic code is now active for the ether circuit.

Results:

• OK - A 06 diagnostic code was active before disconnecting the wire. A 05 diagnostic code became active after disconnecting the wire.

  Repair: Temporarily connect a new ether relay. Activate the ether override. Verify that there are no active diagnostic codes for the ether circuit. If there are no active diagnostic codes for the ether circuit, permanently install the new relay. Clear any logged diagnostic codes.

  STOP

• Not OK - A 06 diagnostic code is still active. Leave the wire disconnected from the relay. Proceed to Test Step 5.

Test Step 4. Create a Short at the Ether Relay

1. Remove electrical power from the ECM.

2. Disconnect the wire to the coil of the ether relay from ECM connector P1-21.

3. Install a jumper wire between the wire and engine ground.

4. Restore electrical power to the ECM.

5. Proceed to the "Diagnostic Overrides" screen on Cat ET.

6. Activate the ether injection system. The diagnostic override will activate for ten seconds.

   Note: Monitor the "Active Diagnostic Codes" screen on Cat ET.

7. Check for an active 06 diagnostic code for the ether circuit.

8. Remove electrical power from the ECM. Remove the wire jumper.

Expected Result:

A 06 diagnostic code is active when the jumper wire is installed. A 05 diagnostic code is active when the jumper wire is removed.

Results:

• OK - The engine harness and the ECM are OK.

  Repair: Check the wire from the other side of the ether coil for continuity to engine ground. If the wire has continuity to engine ground the ether coil has an open. Reconnect all wires to the original configuration. Temporarily connect a new ether relay. Activate the ether override. Verify that there are no active diagnostic codes for the ether circuit. If there are no active diagnostic codes for the ether circuit, permanently install the new relay. Clear any logged diagnostic codes.

  STOP

• Not OK - The 05 diagnostic code remains active with the jumper in place. The open circuit is between the ECM and the ether relay. Proceed to Test Step 5.

Test Step 5. Check the Operation of the ECM

1. Check the operation of the ECM by creating an open in the ether circuit at the ECM.

   1. Remove electrical power from the ECM.

   2. Fabricate a jumper wire that is long enough to reach from a terminal at the ECM connector to the engine ground stud. Crimp a connector socket to one end of the jumper wire.

   3. Disconnect the J1/P1 ECM connector.

   4. Remove the wire from ECM connector P1-20. Install the jumper wire into the terminal location for the ether relay.

   5. Reconnect the ECM connector.

   6. Restore electrical power to the ECM.

   7. Proceed to the "Diagnostic Overrides" screen on Cat ET.

   8. Activate the ether injection system. The diagnostic override will activate for ten seconds.

      Note: Monitor the "Active Diagnostic Codes" screen on Cat ET.

   9. Check for an active 05 diagnostic code for the ether circuit.

2. Check the operation of the ECM by creating a short at the ECM.

   1. Connect the wire jumper in P1-21 to the engine ground stud.

   2. Restore electrical power to the ECM.

   3. Proceed to the "Diagnostic Overrides" screen on Cat ET.

   4. Activate the ether injection system. The diagnostic override will activate for ten seconds.

      Note: Monitor the "Active Diagnostic Codes" screen on Cat ET.

   5. Check for an active 06 diagnostic code for the ether circuit.

3. Remove electrical power from the ECM. Reconnect all wires to the original configuration.

Expected Result:

A 05 diagnostic code is active when the wire from the ether solenoid is removed from the ECM connector. A 06 diagnostic code is active when the wire for the ether relay is connected to the engine ground stud.

Results:

• OK - The ECM is operating properly. The problem is in the wiring between the ECM and the ether relay.

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

  STOP

• Not OK - One of the following conditions exists: The 05 diagnostic code is not active when the wire for the relay is disconnected. The 06 diagnostic code is not active when the wire jumper is installed.

  Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM". Verify that the problem is resolved.

  STOP

Test Step 6. Check for Voltage at the Switched Contacts of the Ether Relay

Note: The ether canister must be removed prior to activating this test.

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

2. Remove electrical power from the ECM.

3. Disconnect the wire from the ether relay to the ether solenoid at the ether relay.

4. Restore electrical power to the ECM.

5. Proceed to the "Diagnostic Overrides" screen on Cat ET.

6. Activate the ether injection system. The diagnostic override will activate for ten seconds.

7. Measure the voltage between engine ground and the terminals of the switched contacts of the ether relay.

8. Remove electrical power from the ECM. Reconnect the wire to the ether relay.

Expected Result:

The voltage measures 24 ± 3.0 VDC at both terminals.

Results:

• OK - The voltage measures 24 ± 3.0 VDC on both terminals. Proceed to Test Step 7.

• Not OK - The voltage does not measure 24 ± 3.0 VDC at either terminal.

  Repair: If voltage is not present at either terminal, repair the wire between the battery and the ether relay.

  STOP

• Not OK - The voltage does not measure 24 ± 3.0 VDC at the terminal to the ether solenoid.

  Repair: If voltage is not present at the terminal to the ether solenoid and no diagnostic codes are active for the ether system, replace the ether relay.

  STOP

Test Step 7. Check for Voltage at the Ether Solenoid

1. Remove electrical power from the ECM.

2. Disconnect the wire from the ether relay to the ether solenoid at the ether solenoid.

3. Restore electrical power to the ECM.

4. Proceed to the "Diagnostic Overrides" screen on Cat ET.

5. Activate the ether injection system. The diagnostic override will activate for ten seconds.

6. Measure the voltage between the wire that was disconnected at the ether solenoid and engine ground.

7. Remove electrical power from the ECM.

Expected Result:

The voltage measures 24 ± 3.0 VDC.

Results:

• OK - The voltage measures 24 ± 3.0 VDC.

  Repair: Verify that the wire from the ether solenoid to engine ground has continuity to engine ground. If the ether solenoid is not activating the ether valve, check for a mechanical problem. If no mechanical problem is found, replace the ether solenoid.

  STOP

• Not OK - The voltage does not measure 24 ± 3.0 VDC.

  Repair: If voltage is not present at the ether solenoid, repair the wire between the ether relay and the ether solenoid.

  STOP