C7.1 Industrial Engine and Generator Set Caterpillar

This procedure covers the following codes:

When the ambient temperature is between 10 °C (50 °F) and −25 °C (−13 °F), glow plugs are used as a starting aid. When the ambient temperature is below −25 °C (−13 °F), the ether injection system is used as a starting aid. The ECM controls the ether injection system.

If there is an active engine shutdown, the ether injection system is disabled .

A test on the electronic service tool allows the technician to activate the ether system. The test is functional when the engine speed is zero rpm. Access the test via the "Override Parameters" screen on the electronic service tool.

Illustration 1	g02113581
Schematic of the ether injection system

Illustration 2	g01160725
Connector for the ether start valve (1) Ether solenoid (2) Solenoid return

Illustration 3	g01981073
Typical example of the pin locations on the P1 connector (12) Ether injection signal (59) Ether solenoid return

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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 the Electrical Connectors and the Wiring

1. Remove electrical power from the ECM.

2. Inspect the connector for the ether injection solenoid. Refer to Troubleshooting, "Electrical Connectors - Inspect".

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

4. Check the screw for the ECM connector for the correct torque of 6 N·m (53 lb in).

5. Check the harness and the wiring for abrasion and for pinch points from the ether injection solenoid to the ECM.

Expected Result:

All connectors, pins, and sockets are correctly connected, and the harness and wiring are free of corrosion, of abrasion and of pinch points.

Results:

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

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

  Repair: Repair the connectors and/or the wiring. Replace parts, if necessary.

  If necessary, use the electronic service tool to perform a "Wiggle Test".

  Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.

  STOP

Test Step 2. Check for Active Diagnostic Codes

Note: Remove the ether canister before you perform this procedure.

1. Connect the electronic service tool to the diagnostic connector. Refer to Troubleshooting, "Electronic Service Tools".

2. Restore electrical power to the engine ECM.

3. Proceed to the "Diagnostic Overrides" screen on the electronic service tool.

4. Activate the ether injection system. The system will activate for 10 seconds.

5. Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes.

   Note: Wait at least 30 seconds in order for the diagnostic codes to become active.

6. Check for a 626-5 diagnostic code or a 626-6 diagnostic code.

Results:

• Neither diagnostic code is active. -

  Repair: An intermittent fault may have been caused by a poor electrical connection. Carefully inspect the connectors and the wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect".

  STOP

• A 626-6 code is active at this time - Proceed to Test Step 3.

• A 626-5 code is active at this time - Proceed to Test Step 4.

Test Step 3. Create an Open at the Harness Connector for the Ether Injection Solenoid

1. Remove electrical power from the engine ECM.

2. Disconnect the connector for the solenoid.

3. Restore electrical power to the engine ECM.

4. Proceed to the "Diagnostic Overrides" screen on the electronic service tool.

5. Activate the ether injection system. The system will activate for 10 seconds.

6. Monitor the active diagnostic code screen on the electronic service tool. Check for a 626-5 code.

   Note: Wait at least 30 seconds in order for the diagnostic codes to become active.

7. Remove electrical power from the engine ECM.

Expected Result:

A 626-5 code is now active.

Results:

• A 626-6 code was active before the connector was disconnected. A 626-5 code became active after the connector was disconnected. -

  Repair: Temporarily connect a new solenoid to the harness, but do not install the new solenoid. Use the electronic service tool in order to verify that the repair eliminates the fault.

  If there are no active codes for the ether injection system, permanently install the new solenoid.

  Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.

  STOP

• A 626-6 code was active before the connector was disconnected. The 626-6 code remained active after the connector was disconnected. - Leave the connector for the solenoid disconnected. Proceed to Test Step 5.

Test Step 4. Create a Short at the Connector for the Ether Injection Solenoid

1. Remove electrical power from the engine ECM.

2. Disconnect the connector for the solenoid.

3. Fabricate a jumper wire that can be used to create a short between terminal 1 and terminal 2 at the connector for the solenoid. Crimp connector pins to each end of the jumper wire.

4. Install the jumper wire between terminals 1 and 2 of the harness connector.

5. Restore electrical power to the engine ECM.

6. Proceed to the "Diagnostic Overrides" screen on the electronic service tool.

7. Activate the ether injection system. The system will activate for 10 seconds.

8. Monitor the active diagnostic code screen on the electronic service tool. Check for a 626-6 code.

   Note: Wait at least 30 seconds in order for the diagnostic codes to become active.

9. Remove electrical power from the engine ECM. Remove the jumper wire from the connector.

Expected Result:

A 626-6 code is now active.

Results:

• A 626-5 code was active before the jumper wire was installed. A 626-6 code became active after the jumper wire was installed. -

  Repair: The engine harness and the ECM are OK. Temporarily connect a new solenoid to the harness, but do not install the new solenoid. Use the electronic service tool in order to verify that the repair eliminates the fault. If there are no active diagnostic codes for the solenoid, permanently install the new solenoid.

  Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.

  STOP

• A 626-5 code was active before the jumper wire was installed. The 626-5 code remained active after the jumper wire was installed. - Remove the jumper wire and connect the connector. Proceed to Test Step 5.

Test Step 5. Bypass the Wiring for the Solenoid

1. Remove electrical power from the engine ECM.

2. Disconnect the P1 ECM connector and the connector for the ether injection solenoid.

3. Thoroughly inspect the P1/J1 connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".

4. Remove the wire from terminal 1 on the connector for the ether injection solenoid. Remove the wire from P1:12.

5. Fabricate a jumper wire that is long enough to reach from the connector for the ether injection solenoid to the ECM.

6. Insert one end of the jumper into terminal 1 on the connector for the ether injection solenoid. Insert the other end of the jumper into P1:12.

7. Remove the wire from terminal 2 on the connector for the ether injection solenoid. Remove the wire from P1:59.

8. Fabricate a jumper wire that is long enough to reach from the connector for the ether injection solenoid to the ECM.

9. Insert one end of the jumper into terminal 2 on the connector for the ether injection solenoid. Insert the other end of the jumper into P1:59.

10. Proceed to the "Diagnostic Overrides" screen on the electronic service tool.

11. Activate the ether injection system. The system will activate for 10 seconds.

12. Monitor the active diagnostic code screen on the electronic service tool.

13. Remove the jumper wires and replace all wires to the original configuration.

Results:

• There are no active 626 diagnostic codes when the jumpers are installed. - The fault is in the wiring between the ECM and the solenoid connector.

  Repair: Repair the faulty harness or replace the faulty harness.

  Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.

  STOP

• The diagnostic code is still active with the jumper installed. -

  Repair: Perform the following procedure:

  1. Make sure that the latest flash file for the application is installed in the ECM. Refer to Troubleshooting, "Flash Programming".

  2. Contact the Technical Communicator at a Caterpillar dealer.

     Note: This consultation can greatly reduce the repair time.

  3. If the Technical Communicator recommends the use of a test ECM, install a test ECM. Refer to Troubleshooting, "Replacing the ECM".

  4. Use the electronic service tool to recheck the system for active diagnostic codes.

  5. If the fault is eliminated with the test ECM, reconnect the suspect ECM.

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

  7. Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.

  STOP