3500B and 3500C Locomotive Engines Caterpillar

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.

When the engine is in auto mode, the engine uses an ether injection system to improve starting in cold temperatures. The duration of the ether cycle is based on the engine coolant temperature. The ECM, which controls the ether injection system, uses the engine coolant temperature sensor to detect engine temperature. The ECM determines if ether should be injected by monitoring actual engine rpm and the engine temperature. The ECM will activate the ether start relay if the engine coolant temperature is below a set temperature and the engine rpm is below a certain level. The ether injection system becomes enabled at 10 °C (50 °F). The ether injection system will run for a minimum of 10 seconds up to a maximum of 130 seconds at −40 °C (−40 °F). The automatic ether injection system is disabled whenever engine rpm exceeds 1900 rpm or the engine coolant temperature exceeds 10 °C (50 °F).

The ether injection system can also be operated in manual mode. The ether injection system is switched into manual mode whenever the starting aid switch is depressed. Ether is injected in manual mode if the starting aid switch is depressed and the coolant temperature is below the maximum limit. The manual mode will allow ether to be injected for a maximum of 130 seconds when the switch is toggled. Manual mode allows ether to be injected whenever the coolant temperature is less than 10 °C (50 °F) and engine rpm is greater than 50 rpm.

Note: The ether function will be disabled if the ether control parameter is disabled.

Illustration 1	g01258710
Typical schematic

Illustration 2	g01213344
P1 ECM connector (P1-5) Digital return (P1-20) Ether aid switch

Illustration 3	g01213347
P2 ECM connector (P2-10) Ether start relay

Illustration 4	g01234146
Location of ECM connectors

Illustration 5	g01258712
Connector "A" (Terminal 25) Digital return

Illustration 6	g01258713
Connector "B" (Terminal 31) Ether aid switch (Terminal 32) Ether start relay

Show/hide table

Personal injury or death can result from using ether. Failure to follow these instructions could result in an explosion and/or fire and possible personal injury. When using starting fluid, follow the manufacturer's instructions carefully. Use ether sparingly and spray it only while cranking the engine. Also, do not store starting fluid containers in the cab.

Test Step 1. INSPECT ELECTRICAL CONNECTORS AND WIRING

1. Turn the breaker for the ECM to the OFF position.

2. Thoroughly inspect the J1/P1 ECM connector and the J2/P2 ECM connector. Inspect all of the connectors that are associated with the circuit.

   Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.

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

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

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

Expected Result:

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

Results:

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

• Not OK - There is a problem with 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 THE ETHER CANISTER

1. Remove the ether canister from the ether solenoid. Determine if the canister contains any ether. Ether can not be injected if the canister is empty.

Expected Result:

The ether canister is not empty.

Results:

• OK - The ether canister is not empty. Proceed to Test Step 3.

• Not OK - The ether canister is empty.

  Repair: Replace the empty ether canister with a new ether canister. Verify that the problem is no longer present.

  STOP

Test Step 3. CHECK FOR ACTIVE DIAGNOSTIC CODES

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

2. Turn the breaker for the ECM to the ON position.

3. Monitor the active diagnostic code screen on Cat ET. Check the ether system for an active diagnostic code.

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

4. Select diagnostic tests from Cat ET.

5. Select the "Override Parameters" screen on Cat ET.

6. Activate the ether override.

7. Monitor the active diagnostic code screen on Cat ET. Check the ether system for an active diagnostic code.

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

8. Disable the ether override.

Expected Result:

An active diagnostic code is not present.

Results:

• OK - An active diagnostic code is not present. A problem is suspected with the ether solenoid. Proceed to Test Step 7.

• OK - An active diagnostic code or a logged diagnostic code is not present. A problem is suspected with the ether aid switch. Proceed to Test Step 9.

• Not OK - A -5 code was active before the ether override was activated. Proceed to Test Step 4.

• Not OK - A -6 code is active after the ether override is activated. Proceed to Test Step 5.

Test Step 4. CREATE A SHORT CIRCUIT AT THE ETHER START RELAY

1. Turn the breaker for the ECM to the OFF position.

2. Disconnect the wire from terminal 85 of the ether start relay and from terminal 86 of the ether start relay. Short the two wires that were removed from the ether start relay together.

3. Turn the breaker for the ECM to the ON position.

4. Monitor the active diagnostic code screen on Cat ET. Check the ether system for an active diagnostic code.

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

5. Activate the ether override. Monitor the active diagnostic code screen on Cat ET. Check the ether system for an active diagnostic code.

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

Expected Result:

A -6 diagnostic code is now active for the ether start relay.

Results:

• OK - A -6 diagnostic code is now active for the ether start relay.

  Repair: The ECM detected the short circuit at the ether start relay. The wire between the ether start relay and the ECM is OK. The wire from the ether start relay to the −Battery is OK. The ECM is operating correctly. The open must be in the coil of the ether start relay. Replace the ether start relay.

  STOP

• Not OK - The -5 diagnostic code is still active for the ether start relay. The open is in the wiring between the ether start relay and the ECM. Proceed to Test Step 6.

Test Step 5. CREATE AN OPEN AT THE ETHER START RELAY

1. Turn the breaker for the ECM to the OFF position.

2. Remove the wire from terminal 85 of the ether start relay that is between the ether start relay and the ECM connector P2-10.

3. Turn the breaker for the ECM to the ON position.

4. Monitor the active diagnostic code screen on Cat ET. Check the ether system for an active diagnostic code.

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

5. Activate the ether override. Monitor the active diagnostic code screen on Cat ET. Check the ether system for an active diagnostic code.

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

Expected Result:

A -5 diagnostic code is now active for the ether start relay.

Results:

• OK - A -5 diagnostic code is now active for the ether start relay. The ECM detected the open circuit at the ether start relay.

  Repair: The ECM is operating correctly. The wire between the ether start relay and the ECM is OK. Verify that the wire from the ether start relay to the −Battery is not shorted to engine ground. The short must be in the coil of the ether start relay. Replace the ether start relay.

  STOP

• Not OK - The -6 diagnostic code is still active for the ether start relay. The short circuit is in the wiring between the ether start relay and the ECM. Proceed to Test Step 6.

Test Step 6. TEST THE OPERATION OF THE ECM

1. Turn the breaker for the ECM to the OFF position.

2. Fabricate a jumper wire that can be used to replace the wire to the ether start relay from the ECM connector. Crimp a connector socket to one end of the jumper wire.

3. Disconnect the J2/P2 ECM connector.

4. Remove the wire for the ether start relay from the P2 ECM connector.

5. Install the jumper wire into the socket for the wire to the ether start relay.

6. Connect the ECM connector.

7. Check the operation of the ECM by creating an open at the ECM:

   1. Hold the loose end of the jumper wire away from any components in order to create an open circuit condition.

   2. Turn the breaker for the ECM to the ON position.

   3. Monitor the "Active Diagnostic Code" screen on Cat ET. Check the ether system for an active diagnostic code.

      Note: Wait at least 30 seconds so that any codes may become active.

   4. Activate the ether override. Monitor the active diagnostic code screen on Cat ET. Check the ether system for an active diagnostic code.

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

8. Check the operation of the ECM by creating a short circuit at the ECM:

   1. Short the jumper wire in the socket for the ether start relay to engine ground.

   2. Turn the breaker for the ECM to the ON position.

   3. Monitor the "Active Diagnostic Code" screen on Cat ET. Check the ether system for an active diagnostic code.

      Note: Wait at least 30 seconds so that any codes may become active.

   4. Activate the ether override. Monitor the active diagnostic code screen on Cat ET. Check the ether system for an active diagnostic code.

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

   5. Turn the breaker for the ECM to the OFF position.

9. Remove the jumper wire. Return all wiring to the original configuration.

Expected Result:

A -5 diagnostic code is active when the wire to the ether start relay is open at the ECM connector. A -6 diagnostic code is active if the wire to the ether start relay is shorted to engine ground at the ECM connector.

Results:

• OK - A -5 diagnostic code is active when the wire to the ether start relay is open at the ECM connector. A -6 diagnostic code is active if the wire to the ether start relay is shorted to engine ground at the ECM connector.

  Repair: The ECM is operating properly. Repair the wire between the ether start relay and the ECM.

  STOP

• Not OK - One of the following conditions exists: The -5 diagnostic code is not active when the wire to the ether start relay is open at the ECM connector. The -6 diagnostic code is not active when the wire to the ether start relay is shorted at the ECM connector.

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

  STOP

Test Step 7. CHECK THE OUTPUT VOLTAGE FROM THE ETHER START RELAY

1. Turn the breaker for the ECM to the OFF position.

2. Remove wire 150-OR(Orange) from terminal 30 on the ether start relay.

3. Turn the breaker for the ECM to the ON position.

4. Activate the ether override.

5. Measure the voltage between terminal 30 and engine ground at the ether start relay.

6. Measure the voltage between terminal 87 and engine ground at the ether start relay.

7. Disable the ether override.

8. Reconnect all wiring to the original configuration.

Expected Result:

The voltage is 24 ± 3 VDC at both test points.

Results:

• OK - The voltage is 24 ± 3 VDC. The ether start relay is operating correctly. Proceed to Test Step 8.

• Not OK - The voltage is not 24 ± 3 VDC on terminal 87.

  Repair: Check wire 150-OR(Orange) for continuity to the +Battery. Inspect any circuit protection. Repair any problems.

  STOP

• Not OK - The voltage is not 24 ± 3 VDC on terminal 30.

  Repair: If voltage is present on terminal 87 of the ether start relay and no diagnostic codes are present for the ether start relay, replace the ether start relay.

  STOP

Test Step 8. CHECK THE VOLTAGE AT THE ETHER SOLENOID

1. Turn the breaker for the ECM to the OFF position.

2. Remove wire 150-OR(Orange) from the ether solenoid.

3. Turn the breaker for the ECM to the ON position.

4. Activate the ether override.

5. Measure the voltage between wire 150-OR(Orange) and the engine ground at the ether solenoid.

6. Disable the ether override.

7. Reconnect all wiring to the original configuration.

Expected Result:

The voltage is 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC. Wire 150-OR(Orange) is OK between the ether start relay and the ether solenoid.

  Repair: If voltage is present at the ether solenoid, verify that wire 229-BK(Black) has continuity to the −Battery. If wire 229-BK(Black) is OK, replace the ether solenoid.

  STOP

• Not OK - The voltage is not 24 ± 3 VDC on wire 150-OR(Orange) at the ether solenoid.

  Repair: Repair wire 150-OR(Orange) between the ether start relay and the ether solenoid.

  STOP

Test Step 9. CHECK THE STARTING AID SWITCH

1. Disconnect wires 998-BR(Brown) and F720-PU(Purple) from the starting aid switch.

2. Turn the breaker for the ECM to the ON position.

3. Observe the starting aid switch status on Cat ET.

4. Short the wires together at the starting aid switch.

5. Observe the starting aid switch status on Cat ET.

6. Turn the breaker for the ECM to the OFF position.

Expected Result:

When the wires are disconnected from the starting aid switch, the status on Cat ET for the starting aid switch displays "OFF". The status on Cat ET for the starting aid switch displays "ON" when the switch wires are shorted together.

Results:

• OK - When the wires are disconnected from the starting aid switch, the Cat ET screen displays "OFF". The Cat ET screen displays "ON" when the switch wires are shorted together.

  Repair: Replace the starting aid switch.

  STOP

• Not OK - When the wires are disconnected from the starting aid switch, the Cat ET screen does not display "OFF". The Cat ET screen does not display "ON" when the switch wires are shorted together. There is a short or an open in the wiring harness between the starting aid switch and the ECM.

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

  STOP