365B, 365B Series II, 365BL, 365BL Series II, 385B and 5090B Excavators Vital Information Management System (VIMS) Caterpillar

Illustration 1	g00697998
Schematic of the Engine Coolant Level Switch

Use this procedure in order to troubleshoot the engine coolant level switch under the conditions that are listed below:

• The engine coolant is at a normal level and the VIDS is warning the operator of a "LOW" engine coolant condition.

• The engine coolant is below the lower limit and the VIDS is NOT warning the operator of the "LOW" engine coolant condition.

The possible causes of this failure are listed below:

• The signal circuit in the machine harness is open.

• The signal circuit is shorted to ground.

• The ground circuit is open.

• The switch has failed.

• The VIDS ECM has failed.

Test Step 1. VERIFY THE STATUS OF THE LEVEL SWITCH.

1. Turn the disconnect switch and the key start switch to the ON position.

2. Verify that the level switch does not report a low level, even though the level is low.

Expected Result:

The level switch does not report a low level, even though the level is low.

Results:

• OK - The level switch does not report a low level, even though the level is low. Proceed to test step 2.

• NOT OK - The level switch reports a low level even when the level is normal. Proceed to test step 6.

Test Step 2. CHECK THE SWITCH

1. The disconnect switch and the key start switch remain in the ON position.

2. On the VIDS keypad, press the "Gauge" key three times.

3. Then enter the parameter number 808 with the VIDS keypad. (This will display the status of the engine coolant level on the message center.)

4. Verify that the status of the coolant level switch is "OK".

5. Disconnect the engine coolant level switch from the machine harness.

Expected Result:

The status of the engine coolant level changes from "OK" to "LOW".

Results:

• OK - The status of the engine coolant level changes from "OK" to "LOW". The switch has failed.

  Repair: Replace the Switch.

  Stop.

• NOT OK - The status of the engine coolant level did not change. Proceed to test step 3.

Test Step 3. CHECK THE GROUND CIRCUIT OF THE SWITCH

1. Turn the key start switch and the disconnect switch to the OFF position.

2. The engine coolant level switch remains disconnected from the machine harness connector.

3. At the machine harness connector for the switch, measure the resistance between contact 2 (wire 200-BK) of the machine harness connector and frame ground.

Expected Result:

The resistance is less than 5 ohms.

Results:

• OK - The resistance is less than 5 ohms. The circuit is correct. Proceed to test step 4.

• NOT OK - The resistance is greater than 5 ohms. The ground circuit is open.

  Repair: Repair the machine harness or replace the machine harness.

  Stop.

Test Step 4. CHECK THE VIDS ECM

1. Turn the disconnect switch and the key start switch to the ON position.

2. At the machine harness connector for the switch, measure the voltage between contact 1 (wire 412-BU) and contact 2 (wire 200-BK) of the machine harness.

Expected Result:

The voltage is 8.0 ± 1.0 DCV.

Results:

• OK - The voltage is 8.0 ± 1.0 DCV. The voltage is correct. The ECM has failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the failure is still unknown, replace the ECM. See the Testing and Adjusting, "Module - Replace" section of this manual.

  Stop.

• NOT OK - The voltage is not 8.0 ± 1.0 DCV. The voltage is not correct. Proceed to test step 5.

Test Step 5. CHECK THE SIGNAL CIRCUIT IN THE MACHINE HARNESS

1. Turn the key start switch and the disconnect switch to the OFF position.

2. The coolant level switch remains disconnected from the machine harness connector.

3. Disconnect the machine harness connector J1 from the VIDS ECM.

4. At the machine harness connector for the switch, measure the resistance between contact 1 (wire 412-BU) of the machine harness connector and frame ground.

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• OK - The resistance is greater than 5000 ohms. The circuit is correct. The VIDS ECM has failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the failure is still unknown, replace the ECM. See the Testing and Adjusting, "Module - Replace" section of this manual.

  Stop.

• NOT OK - The resistance is less 5000 ohms. The Circuit is not correct. The harness has failed.

  Repair: Repair the machine harness or replace the machine harness.

  Stop.

Test Step 6. CHECK THE SWITCH

1. The disconnect switch and the key start switch remain in the ON position.

2. On the VIDS keypad, press the "Gauge" key three times.

3. Then enter the parameter number 808 with the VIDS keypad. (This will display the status of the engine coolant level on the message center.)

4. Verify that the status of the coolant level switch is "LOW".

5. Turn the key start switch and the disconnect switch to the OFF position.

6. Disconnect the engine coolant level switch from the machine harness.

7. Place a jumper wire between contact 1 (wire 412-BU) and contact 2 (wire 200-BK).

8. Turn the disconnect switch and the key start switch to the ON position.

9. Verify the status of the engine coolant level switch.

Expected Result:

The status of the engine coolant level changed from LOW to OK.

Results:

• OK - The status of the engine coolant level changed from LOW to OK. The switch has failed.

  Repair: Replace the switch.

  Stop.

• NOT OK - The status of the engine coolant level did not change. Proceed to test step 7.

Test Step 7. CHECK THE SIGNAL CIRCUIT

1. Turn the key start switch and the disconnect switch to the OFF position.

2. Remove the jumper wire from contact 2 (wire 200-BK) of the machine.

3. Short the unattached end of the jumper wire to frame ground.

4. Turn the disconnect switch and the key start switch to the ON position.

5. Verify the status of the engine coolant level switch.

Expected Result:

The status of the engine coolant level changed from LOW to OK.

Results:

• OK - The status of the engine coolant level changed from LOW to OK. The ground circuit of the machine harness has failed.

  Repair: Repair the machine harness or replace the machine harness.

  Stop.

• NOT OK - The status of the engine coolant level did not change. Proceed to test step 8.

Test Step 8. CHECK THE SIGNAL CIRCUIT

1. Turn the key start switch and the disconnect switch to the OFF position.

2. Remove the jumper wire from the machine harness connector of the switch.

3. Disconnect the machine harness connector J1 from the VIDS ECM.

4. Measure the resistance of the signal circuit from contact J1 (wire 412-BU) to contact 1 (wire 412-BU) of the machine harness connector for the switch.

Expected Result:

The resistance is less than 5 ohms.

Results:

• OK - The resistance is less than 5 ohms. The circuit is correct. The VIDS ECM has failed.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the failure is still unknown, replace the ECM. See the Testing and Adjusting, "Module - Replace" section of this manual.

  Stop.

• NOT OK - The resistance is greater than 5000 ohms. The signal circuit is open. The machine harness has failed.

  Repair: Repair the machine harness or replace the machine harness.

  Stop.