3512B Engine for SPF343, SPS343, and SPT343 Pumpers Caterpillar

The Electronic Control Module (ECM) receives two signals from the "Deck Start/Run/Kill" switch. A signal is provided to the ECM in order to determine when the "Deck Start/Run/Kill" switch is active.

When both of the signals are high, the switch is NOT active.

When both of the signals are low, the switch is active.

If two different signals are detected during the powerup, the ECM will determine that one of the signals is incorrect. A diagnostic code will be logged and a diagnostic code will remain active.

The engine will continue to run when the ECM detects two different signals. If both of the signals are high, the engine will stop.

The "Deck Start/Run/Kill" switch is included in the engine start system. Turning the "Deck Start/Run/Kill" switch to the START position energizes the "Start Deck Engine Relay (SDER)". The "Start Deck Engine Relay (SDER)" will be latched in the ON position through a set of normally open contacts. The Start/Run/Stop inputs to the ECM are kept low through a different set of normally open contacts from the "Start Deck Engine Relay (SDER)". The ECM will begin the engine start sequence, when the ECM inputs go low and the engine is not running.

Turning the "Deck Start/Run/Kill" switch to the "KILL" position will energize the "Normal Kill Relay (NKR)". A set of normally closed contacts from the "Normal Kill Relay (NKR)" will open de-energizing the "Start Deck Engine Relay (SDER)". The contacts from the "Start Deck Engine Relay (SDER)" will open and the Start/Run/Stop inputs to the ECM will go high. The ECM will begin the engine shutdown when the ECM inputs go high.

Illustration 1	g00854421
Typical example

Test Step 1. Check for Connector Damage.

1. Turn the circuit breaker CB-8 to the OFF position.

2. Turn the main disconnect switch to the OFF position.

3. Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.

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

5. Check the ECM connector (allen head screw) for the proper torque of 6.0 N·m (55 lb in).

6. Check the customer connector (allen head screw) for the proper torque of 2.25 ± 0.25 N·m (20 ± 2 lb in).

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

Expected Result:

The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.

Results:

• OK - The connectors and wiring are okay. Proceed to test step 2.

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

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

  Stop.

Test Step 2. Monitor the Parameter for the Start/Run/Stop Switch on the Caterpillar Electronic Technician (ET).

1. Start the Cat ET.

2. Turn the circuit breaker CB-8 to the ON position.

3. Turn the main disconnect switch to the ON position.

4. Turn the "Master Power" switch to the ON position.

5. Turn the "Gear Selector" knob to the NEUTRAL position.

6. Monitor the parameter for the Start/Run/Stop switch on Cat ET.

7. Turn the "Deck Start/Run/Kill" switch to the START position.

Expected Result:

The parameter for the Start/Run/Stop switch should read "ON".

Results:

• OK - The parameter for the Start/Run/Stop switch does read "ON".

  Repair: The "Deck Start/Run/Kill" switch circuit is operating properly. Check for diagnostic codes.

  Stop.

• Not OK - The parameter for the Start/Run/Stop switch does not read "ON". Proceed to test step 3.

Test Step 3. Check the Voltage from the "Deck Start/Run/Kill" Switch.

1. Connect a voltmeter between terminal 10 in the main junction box and engine ground.

2. Turn the "Deck Start/Run/Kill" switch to the START position.

3. Monitor the voltage on the voltmeter.

4. Turn the "Deck Start/Run/Kill" switch to the RUN position.

5. Monitor the voltage on the voltmeter.

6. Turn the "Deck Start/Run/Kill" switch to the "KILL" position.

Expected Result:

The voltage should measure 12 ± 1 VDC.

Results:

• OK - The voltage measures 12 ± 1 VDC. Proceed to test step 4.

• Not OK - START/RUN Position - The voltage does not measure 12 ± 1 VDC in either the START or the RUN positions. Proceed to test step 6.

• Not OK - RUN Position - The voltage does not measure 12 ± 1 VDC in the RUN position.

  Repair: Check the normally open contacts on terminals 9 and 5 of the "Start Deck Engine Relay (SDER)" for proper operation. Voltage should be present on terminal 5 when the "Start Deck Engine Relay (SDER)" is energized and the "Deck Start/Run/Kill" switch is in the RUN position. These contacts latch the "Start Deck Engine Relay (SDER)" in the energized state. If the normally open contacts on terminals 9 and 5 are okay, check the wire between the "Main Junction Box" terminal 10 and terminal 13 of the "Start Deck Engine Relay (SDER)". Check continuity between terminal 14 of the "Start Deck Engine Relay (SDER)" and engine ground. If the wire is okay, replace the "Start Deck Engine Relay (SDER)". Verify that the circuit is operating properly.

  Stop.

Test Step 4. Check the Voltage at the Normally Open Contacts of the "Start Deck Engine Relay (SDER)".

1. Connect a voltage test lamp between terminal 103 and terminal 101 in the main junction box.

2. Monitor the voltage test lamp.

3. Turn the "Deck Start/Run/Kill" switch to the START position.

4. Monitor the voltage test lamp.

Expected Result:

The voltage test lamp should illuminate before the "Deck Start/Run/Kill" switch is turned to the START position. The voltage test lamp should not illuminate after the "Deck Start/Run/Kill" switch is turned to the START position.

Results:

• OK - The voltage test lamp illuminates before the "Deck Start/Run/Kill" switch is turned to the START position. The voltage test lamp does not illuminate after the "Deck Start/Run/Kill" switch is turned to the START position.

  Repair: The "Deck Start/Run/Kill" switch and related wiring are operating correctly. Check for active diagnostic codes that indicate other problems.

  Stop.

• Not OK - The voltage test lamp illuminates after the "Deck Start/Run/Kill" switch is turned to the START position.

  Repair: Verify that the "Fuel Cutoff Relay (FCR)" is not in the ON position. The normally open contacts on terminals 10 and 6 of the "Start Deck Engine Relay (SDER)" are faulty. Replace the "Start Deck Engine Relay (SDER)". Verify that the circuit is operating properly.

  Stop.

• Not OK - The voltage test lamp does not illuminate before the "Deck Start/Run/Kill" switch is turned to the START position. Proceed to test step 5.

Test Step 5. Check the Voltage at the Start/Run/Stop Inputs to the ECM.

1. Disconnect the main power.

2. Disconnect ECM connector J1/P1.

3. Remove wire F717-WH in ECM connector P1-14. Install a wire jumper into the socket for P1-14.

4. Remove wire F716-WH in ECM connector P1-08. Install a wire jumper into the socket for P1-08.

5. Connect a voltage test lamp between the wire jumpers in P1-08 and P1-14 and engine ground.

6. Connect the main power.

7. Monitor the voltage test lamp.

8. Disconnect the main power. Remove the wire jumpers and replace all wires and connectors.

Expected Result:

The voltage test lamp should illuminate.

Results:

• OK - The voltage test lamp illuminates.

  Repair: The wire and/or connectors between terminal 103 in the main junction box and ECM connector P1 need repair. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the circuit is operating properly.

  Stop.

• Not OK - The voltage test lamp does not illuminate.

  Repair: The ECM is not generating the correct output voltage. Verify that the ECM is receiving 24 ± 3 VDC on pins P1-23, P1-04 and P1-06. If voltage is present on the pins replace the ECM. Perform the diagnostic procedure Troubleshooting, "Replacing the ECM".

  Stop.

Test Step 6. Check the Voltage at the "Deck Start/Run/Kill" Switch in the Remote Panel.

1. Connect a voltmeter between terminal 10 in the remote panel and engine ground.

2. Turn the "Deck Start/Run/Kill" switch to the START position.

3. Monitor the voltage on the voltmeter.

Expected Result:

The voltage should measure 12 ± 1 VDC.

Results:

• OK - The voltage measures 12 ± 1 VDC.

  Repair: The wire and/or connectors from terminal 10 in the remote panel to terminal 10 in the main junction box needs repair. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the circuit is operating properly.

  Stop.

• Not OK - The voltage does not measure 12 ± 1 VDC. Proceed to test step 7.

Test Step 7. Check the Voltage from the "Master Power" Switch.

1. Connect a voltmeter between terminal 47 in the remote panel and engine ground.

2. Monitor the voltage on the voltmeter.

Expected Result:

The voltage should measure 12 ± 1 VDC.

Results:

• OK - The voltage measures 12 ± 1 VDC. Proceed to test step 8.

• Not OK - The voltage does not measure 12 ± 1 VDC.

  Repair: Check the voltage back through each component to circuit breaker CB-1. Refer to Illustration 1. The problem will be in the component or wiring after you measure voltage of 12 ± 1 VDC. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the circuit is operating properly.

  Stop.

Test Step 8. Check the Wiring to the "Deck Start/Run/Kill" Switch.

1. Verify that the "Neutral Trip Relay" is reset.

2. Place the "Gear Selector" knob in the NEUTRAL position.

3. Place the "Pump Brake" switch in the OFF position.

4. Turn the "Master Power" switch to the OFF position.

5. Remove the wire from terminal 2 of the "Deck Start/Run/Kill" switch.

6. Measure the resistance between the wire that was removed in the previous step and terminal 47 of the remote panel.

7. Reconnect all wires.

Expected Result:

The resistance should measure less than 10 Ohms.

Results:

• OK - The resistance measures less than 10 Ohms.

  Repair: The "Deck Start/Run/Kill" switch needs repair. Replace the "Deck Start/Run/Kill" switch. Verify that the circuit is operating properly.

  Stop.

• Not OK - The resistance measures more than 10 Ohms.

  Repair: Check the resistance back through each component to terminal 47 of the remote panel. Refer to Illustration 1. The problem will be in the component or wiring after you measure a resistance less than 10 Ohms. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the circuit is operating properly.

  Stop.