3500B Engines for Caterpillar Built Power Modules with the ADEM 2 Electronic Control Module Caterpillar

The ECM receives four input signals from the ECS. The input signals allow the control to determine the mode of operation. The ECS can operate in four modes: OFF/RESET, MAN/START, COOLDOWN/STOP and AUTO.

When the ECS is set to the OFF/RESET position, the START/RUN/STOP input and the AUTO input are open. The ECM is not powered. Engine operation will stop when the ECS is switched to this position.

When the ECS is set to the AUTO position, the START/RUN/STOP input is open and the AUTO input is low. The ECM is powered. If the remote START/STOP Switch is closed, the engine start sequence will begin.

When the ECS is set to the MAN/START position, The START/RUN/STOP input is low and the ECS in AUTO input is open. The ECM will begin the engine start sequence.

When the ECS is set to the COOLDOWN/STOP position, the START/RUN/STOP input and the ECS in AUTO input are open. After the engine cooldown, the ECM will shut down the engine.

If the signals from the START/RUN/STOP input are opposite, the ECM determines that one of the signals is faulty. The ECM ignores the signals until power is cycled to the ECM.

If this occurs, the engine must be cranked manually. Use the Manual Crank Switch which is located inside the Electronic Instrument Panel. When the engine is shut down, the ECS must be placed in the OFF/RESET position. This will disconnect power to the ECM. A CID-FMI will be active until the ECM is powered down. The parameter for the Ignition Switch will display "ABNORMAL DATA" until power to the ECM is cycled.

If you close the Remote START/STOP Switch, and the ECS is in the AUTO position, the engine will start. The parameter for the switch will display "ON" or "OFF". This parameter is available on the ET only when the ECS is in the AUTO position.

Illustration 1	g00638329

Test Step 1. Check for Connector Damage

1. Turn the circuit breaker for the battery to the OFF position.

2. Turn the ECS to the OFF/RESET position.

3. Check connectors and wiring for the following problems: damage, corrosion, abrasion and incorrect attachment.

Expected Result:

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

Results:

• OK - Proceed to test step 2.

• Not OK -

  Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. If necessary, replace the ECS.

  Stop.

Test Step 2. Check the Status of the Switch.

1. Turn the circuit breaker for the battery to the ON position.

2. Turn the circuit breaker for the Mag Relay of the Starting Motor System to the OFF position.

3. Activate the emergency stop switch. This will prevent the engine from starting during the following tests.

4. Turn the ECS to the STOP position.

5. Connect an ET to the service tool connector.

6. Observe the parameter for the ignition switch on the ET.

Expected Result:

The parameter for the ignition switch should read "STOP".

Results:

• OK - The ECS is functioning correctly. Proceed to test step 3.

• Not OK - The status for the ignition switch does not display "STOP". Proceed to test step 4.

Test Step 3. Check the Status of the Switch.

1. Turn the ECS to the START position.

2. Observe the parameter for the ignition switch on the ET.

Expected Result:

The parameter for the ignition switch should read "RUN".

Results:

• OK - The ECS is working correctly. Proceed to test step 5.

• Not OK - The status of the Ignition Switch does not display "RUN". Proceed to test step 4.

Test Step 4. Install a Jumper Wire.

1. Turn the ECS to the OFF/RESET position.

2. Disconnect ECM connector P1. Remove P1-14, P1-8 and P1-29.

3. Fabricate a jumper wire.

4. Install the jumper wire at P1. Connect P1-14 and P1-8 to P1-29. Reconnect P1.

5. Turn the ECS to the STOP position.

6. Observe the parameter for the ignition switch on the ET.

7. Turn the ECS to the OFF/RESET position and remove the jumper wire.

Expected Result:

The parameter for the ignition switch should display "RUN" while the jumper wire is installed. The parameter for the ignition switch should display"STOP" when the jumper wire is removed.

Results:

• OK - The parameter for the ignition switch displays the proper states. The problem is not with the ECM. Proceed to test step 6.

• Not OK - The parameter for the ignition switch does not show the correct states.

  Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM".

  Stop.

Test Step 5. Check the Status of the Switch.

1. Turn the ECS to AUTO. Place the Remote START/STOP Switch in the START position.

2. Observe the parameters for the ignition switch on the ET. Observe the parameters for the remote start on the ET.

Expected Result:

The parameter for the ignition switch should read "AUTO". The parameter for the remote start should read "ON".

Results:

• OK - The ECS and the remote START/STOP switch are working correctly. Stop.

• Remote Start Not OK - The parameter for the remote start does not display "ON". There is a problem with the wiring between the remote START/STOP switch and the ECS. Proceed to test step 7.

• Ignition Switch Not OK - The parameter for the Ignition Switch does not display "AUTO". Proceed to test step 8.

Test Step 6. Check Switches And Wiring.

1. Turn the ECS to the OFF position.

2. Disconnect ECM connector J1/P1.

3. Measure the resistance between the digital return P1-29 and P1-8.

4. Measure the resistance between the digital return P1-29 and the P1-14.

5. Turn the ECS to the STOP position and repeat the above two measurements.

Expected Result:

The resistance should be greater than 20,000 Ohm.

Results:

• OK - The resistance is greater than 20,000 Ohm. Proceed to test step 9.

• Not OK - The resistance is less than 20,000 Ohm. There is a short circuit in the ECS.

  Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. If necessary, replace the ECS.

  Stop.

Test Step 7. Check the Switches And Wiring.

1. Turn the ECS to the AUTO position with the Remote START/STOP Switch in the STOP position.

2. Measure the resistance between the digital sensor return P1-29 and the P1-8.

3. Measure the resistance between the digital sensor return P1-29 and the P1-14.

Expected Result:

The resistance should be greater than 20,000 Ohms.

Results:

• OK - The resistance is greater than 20,000 Ohms. The ECS appears to be functioning properly. Proceed to test step 10.

• Not OK - The resistance is less than 20,000 Ohms. There is a short circuit in the ECS.

  Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. If necessary, replace the ECS.

  Stop.

Test Step 8. Install a Jumper Wire.

1. Turn the ECS to the OFF/RESET position.

2. Disconnect ECM connector P1.

3. Remove the wires from P1-19 and P1-29.

4. Fabricate a jumper wire.

5. Install the jumper wire at P1. Connect P1-19 to P1-29. Reconnect P1.

6. Turn the circuit breaker for the battery to the ON position.

7. Turn the ECS to the STOP position.

8. Observe the parameter for the ignition switch on the ET.

9. Turn the ECS to the OFF/RESET position.

10. Remove the jumper wire.

Expected Result:

The parameter for the ignition switch should read "AUTO" while the jumper wire is installed. The parameter for the ignition switch should read "STOP" when the jumper wire is removed.

Results:

• OK - The parameter for the ignition switch displays the proper state. The ECS is functioning correctly at this time. Stop.

• Not OK - The parameter for the ignition switch does not display the correct states. Proceed to test step B.

Test Step 9. Check Switches And Wiring.

1. Turn the circuit breaker for the battery to the OFF position.

2. Turn the ECS to the START position.

3. Measure the resistance between the digital sensor return P1-29 and the P1-8.

4. Measure the resistance between digital sensor return P1-29 and the P1-14.

Expected Result:

The resistance should read less than 10 Ohms.

Results:

• OK - The resistance is less than 10 Ohms. Proceed to test step 7.

• Not OK - The resistance is greater than 10 Ohms. There is an open circuit in the ECS.

  Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. If necessary, replace the ECS.

  Stop.

Test Step 10. Check the Switches and Wiring.

1. Turn the ECS to the AUTO position. Ensure that the Remote START/RUN/STOP Switch is in the START/RUN position.

2. Measure the resistance between the digital sensor return P1-29 and the P1-8.

3. Measure the resistance between the digital sensor return P1-29 and the P1-14.

Expected Result:

The resistance should read less than 10 Ohms.

Results:

• OK - The resistance is less than 10 Ohms. The ECS appears to be functioning properly. Proceed to test step 8.

• Not OK - The resistance is greater than 10 Ohms. There is an open circuit in the ECS.

  Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. If necessary, replace the ECS.

  Stop.