3176C and 3196 Engines
The Electronic Control Module (ECM) detects all of the following conditions:
- Engine oil pressure is in the "Low Oil Pressure Region" in Illustration 1 for two seconds.
- The engine has been running for at least ten seconds.
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| Illustration 1 | g01007250 |
Low oil pressure map ( 3176C and 3196) | |
3406E and 3456 Engines
The Electronic Control Module (ECM) detects all of the following conditions:
- Engine oil pressure is in the "Low Oil Pressure Region" in Illustration 2 for two seconds.
- The engine has been running for at least ten seconds.
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| Illustration 2 | g01007252 |
Low oil pressure map ( 3406E and 3456) | |
System Response:
The ECM will log the warning. The ECM will transmit a warning to the display in the cab. The ECM will reset the warning when the oil pressure rises 70 kPa (10 psi) above the low pressure trip line for 20 seconds.
- None
- There may be a problem with the engine lubrication system.
- There may be a problem with the engine oil pressure sensor.
Test Step 1. Check the Engine Oil Level
- Check the engine oil level.
Expected Result:
The engine oil level is OK.
Results:
- OK - The engine oil level is OK. Proceed to Test Step 2.
- Not OK - The engine oil level is low.
Repair: Add engine oil to the proper level.
STOP
Test Step 2. Verify Proper Sensor Installation
- Check the installation of the engine oil pressure sensor.
- Check the wiring of the engine oil pressure sensor. Refer to the Electrical Schematic for the proper wiring. Ensure that all of the wires and connectors are properly connected.
Expected Result:
The sensor is properly installed and the wiring is correct.
Results:
- OK - The sensor is properly installed. Proceed to Test Step 3.
- Not OK - The sensor is not installed properly.
Repair: Install the engine oil pressure sensor properly. Repair the wiring and/or the connectors to the sensor.Verify that the repair eliminates the problem.
STOP
Test Step 3. Check for Active Diagnostic Codes
- Connect the Caterpillar Electronic Technician (Cat ET) to the service tool connector.
- Check for active diagnostic codes that are related to the atmospheric pressure sensor and/or to the turbocharger outlet pressure sensor.
Expected Result:
There are no diagnostic codes that are related to the atmospheric pressure sensor and/or to the turbocharger outlet pressure sensor.
Results:
- OK - There are no diagnostic codes. Proceed to Test Step 4.
- Not OK - There is a diagnostic code that is related to the atmospheric pressure sensor and/or to the turbocharger outlet pressure sensor.
Repair: Troubleshoot the diagnostic code before continuing with this procedure.
STOP
Test Step 4. Check the Status Screen
- Turn the keyswitch to the ON position. The engine should be off.
- Monitor the status for "Boost Pressure" and "Engine Oil Pressure" on Cat ET.
Expected Result:
"Boost Pressure" and "Engine Oil Pressure" are less than 10 kPa (2 psi).
Results:
- OK - The boost pressure and the engine oil pressure are less than 10 kPa (2 psi). Proceed to Test Step 6.
- Not OK - Boost Pressure - The boost pressure is greater than 10 kPa (2 psi). Proceed to Test Step 8.
- Not OK - Engine Oil Pressure - The engine oil pressure is greater than 10 kPa (2 psi). Proceed to Test Step 9.
- Not OK - Both - The boost pressure and engine oil pressure are greater than 10 kPa (2 psi). Proceed to Test Step 5.
Test Step 5. Check the Supply Voltage to the Pressure Sensors
- Disconnect the atmospheric pressure sensor, the engine oil pressure sensor, and the turbocharger outlet pressure sensor.
- Turn the keyswitch to the ON position.
- Measure the voltage between terminal A (+5V) and terminal B (Common) of each pressure sensor connector on the engine harness.
Expected Result:
The voltage is 5.0 ± 0.16 VDC.
Results:
- OK - The voltage is within the range.
Repair: Reconnect the engine oil pressure sensor and the turbocharger outlet pressure sensor.Temporarily connect a new atmospheric pressure sensor.If the new sensor fixes the problem, reconnect the suspect sensor.If the problem returns, permanently replace the sensor.Verify that the repair eliminates the problem.
STOP
- Not OK - There is a problem with the 5 volt supply.
Repair: Check the J2/P2 ECM connector and the sensor connectors for corrosion and moisture.Check the 5 volt supply wire. Verify that the wire is not cut and that the wire is completely inserted into the connectors for the pressure sensors on the engine harness.Verify that the repair eliminates the problem.
STOP
Test Step 6. Install a Pressure Gauge
- Remove the engine oil pressure sensor from the adapter fitting in the engine.
- Install a 186-4045 Tee into the adapter fitting that is in the engine.
- Install the engine oil pressure sensor onto the 186-4045 Tee .
- Install a 5P-5528 O-Ring Adapter into the open port in the tee fitting.
- Turn the keyswitch to the ON position.
- Monitor the status for "Engine Oil Pressure" on Cat ET.
- Start the engine and run the engine at low idle.
- Compare the pressure reading on the gauge to the pressure reading on Cat ET.
- Monitor the status screen and the gauge while you increase the engine speed.
Expected Result:
The gauge and the status screen are within 35 kPa (5.0 psi) of each other.
Results:
- OK - The sensor is functioning properly. Proceed to Test Step 7.
- Not OK - The sensor is not functioning properly.
Repair: Temporarily install a new sensor.If the new sensor repairs the problem, reinstall the suspect sensor.If the problem returns, replace the sensor.Verify that the repair eliminates the problem.
STOP
Test Step 7. Compare the Readings to the Oil Pressure Map
- Compare the readings from the pressure gauge to the low oil pressure map.
Expected Result:
The engine oil pressure is above the "Low Oil Pressure Region" in the low oil pressure map.
Results:
- OK - The engine oil pressure appears to be OK at this time.STOP
- Not OK - The engine oil pressure is lower than the trip line on the oil pressure map. There is a mechanical problem.
Repair: Refer to Testing and Adjusting, "Engine Oil Pressure - Test".
STOP
Test Step 8. Check the Supply Voltage to the Turbocharger Outlet Pressure Sensor
- Disconnect the turbocharger outlet pressure sensor.
- Turn the keyswitch to the ON position.
- Measure the voltage between terminal A (+5V) and terminal B (Common) of the connector for the turbocharger outlet pressure sensor on the engine harness.
Expected Result:
The voltage is 5.0 ± 0.16 VDC.
Results:
- OK - The voltage is within the range.
Repair: Temporarily connect a new turbocharger outlet pressure sensor.If the new sensor fixes the problem, reconnect the suspect sensor.If the problem returns, permanently replace the sensor.Verify that the repair eliminates the problem.
STOP
- Not OK - There is a problem with the 5 volt supply.
Repair: Check the sensor connector for corrosion and moisture.Check the 5 volt supply wire. Verify that the wire is not cut and that the wire is completely inserted into the connector for the turbocharger outlet pressure sensor on the engine harness.Verify that the repair eliminates the problem.
STOP
Test Step 9. Check the Supply Voltage to the Engine Oil Pressure Sensor
- Disconnect the engine oil pressure sensor.
- Turn the keyswitch to the ON position.
- Measure the voltage between terminal A (+5V) and terminal B (Common) of the connector for the engine oil pressure sensor on the engine harness.
Expected Result:
The voltage is 5.0 ± 0.16 VDC.
Results:
- OK - The voltage is within the range.
Repair: Temporarily connect a new engine oil pressure sensor.If the new sensor fixes the problem, reconnect the suspect sensor.If the problem returns, permanently replace the sensor.Verify that the repair eliminates the problem.
STOP
- Not OK - There is a problem with the 5 volt supply.
Repair: Check the sensor connector for corrosion and moisture.Check the 5 volt supply wire. Verify that the wire is not cut and that the wire is completely inserted into the connector for the engine oil pressure sensor on the engine harness.Verify that the repair eliminates the problem.
STOP