3516B Engine for Caterpillar Built Machines Caterpillar

The Analog Sensor Supply provides power to all analog sensors. The Electronic Control Module (ECM) supplies 5.0 ± 0.2 VDC from the ECM connector J1/P1 to each analog sensor connector. The sensor return line connects to the ECM connector J1/P1. The analog sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM.

Note: The Analog Sensors are not protected from overvoltage. A short from the supply line to the + Battery may damage the sensors. If the CID-FMI 262-03 is logged, it is possible that all of the analog sensors have been damaged. Repair the Analog Sensor Supply and check for any "ACTIVE" Sensor Diagnostic Codes in order to determine if a sensor has failed.

Note: Parameters may affect the behavior of the engine. Users can use the Caterpillar Electronic Technician (ET) in order to monitor parameter settings: warnings, derates, shutdown override setpoints and delay times. The behavior of the ECM may vary from the description that is given in this System Operation section. Refer to the diagnostic procedure Troubleshooting, "System Configuration Parameters" in order to determine if there are any parameters that are affecting engine operation.

The following list contains a description of the Analog Sensors that are found on the engine.

Aftercooler Temperature Sensor - The ECM uses the signal from the sensor to monitor changes in system temperature. The ECM makes adjustments to the system as the engine temperature changes. This allows the engine to operate at optimal performance through a wide range of operating temperatures. The operating range of the sensor is -40 °C to 120 °C (-40 °F to 248 °F).

Coolant Temperature Sensor - Cold Mode operation improves the engine starting ability. Cold Mode operation helps to control white smoke during cold starts. Cold Mode operation helps to improve warm up time of the engine. In Normal Mode, injection timing is varied as a function of engine speed and load. The process of combustion is improved by controlling the injection timing in Cold Mode. Transient engine response is slower in Cold Mode operation. Cold Mode operation is activated when the engine water temperature is below 60 °C (140 °F). Cold Mode operation will remain active until water temperature rises above 63 °C (145 °F). The engine will operate in Cold Mode and in Normal Mode during operation. The operating range of the sensor is -40 °C to 120 °C (-40 °F to 248 °F).

Filtered Engine Oil Pressure Sensor - The sensor is used in conjunction with the Unfiltered Engine Oil Pressure sensor to determine the restriction across the engine oil filters. The ECM uses this sensor to detect low engine oil pressure which may indicate a failed engine oil pump, oil leakage, or low pressure in the engine oil filter. The signal is compared with a map of engine oil pressure versus engine rpm which is stored in the ECM. The sensor output is a DC voltage that varies with engine oil pressure between 0.2 VDC and 4.8 VDC. The sensor is located downstream of the engine oil filter. The operating range of the sensor is 0.0 kPa to 1090 kPa (0.0 psi to 158 psi). The ECM calibrates the sensor within the first five seconds after power is applied to the ECM. The ECM checks the sensor value against an acceptable pressure range. If the pressure value is not in this range, the previous calibration will be used. A manual calibration of the sensor should be done if the sensor or the ECM has been replaced. Refer to the calibration procedure Troubleshooting, "Analog Sensor - Calibrate".

Unfiltered Engine Oil Pressure Sensor - The sensor is used in conjunction with the Filtered Engine Oil Pressure sensor to determine the restriction across the engine oil filters. The sensor output is a DC voltage that varies with unfiltered engine oil pressure between 0.2 VDC and 4.8 VDC. The sensor is located before the engine oil filters in the oil passage of the engine oil filter housing. The operating range of the sensor is 0.0 kPa to 1090 kPa (0.0 psi to 158 psi). The ECM calibrates the sensor within the first five seconds after power is applied to the ECM. The ECM checks the sensor value against an acceptable pressure range. If the pressure value is not in this range, the previous calibration will be used. A manual calibration of the sensor should be done if the sensor or the ECM has been replaced. Refer to the calibration procedure Troubleshooting, "Analog Sensor - Calibrate".

Left Turbocharger Compressor Inlet Pressure Sensor - The sensor is used in conjunction with the Atmospheric Pressure Sensor to determine if the engine air filter is plugged. The sensor indicates if the left turbocharger compressor inlet has a restriction. The sensor output is a DC voltage between 0.2 VDC and 4.8 VDC that varies with left turbocharger compressor inlet pressure. The operating range of the sensor is 0.0 kPa to 111 kPa (0.0 psi to 16 psi). The ECM calibrates the sensor within the first five seconds after power is applied to the ECM. The ECM checks the sensor value against an acceptable pressure range. If the pressure value is not in this range, the previous calibration will be used. A manual calibration of the sensor should be done if the sensor or the ECM has been replaced. Refer to the calibration procedure Troubleshooting, "Analog Sensor - Calibrate".

Right Turbocharger Compressor Inlet Pressure Sensor - The sensor is used in conjunction with the Atmospheric Pressure Sensor to determine if the engine air filter is plugged. The sensor indicates if the right turbocharger compressor inlet has a restriction. The sensor output is a DC voltage between 0.2 VDC and 4.8 VDC that varies with right turbocharger compressor inlet pressure. The operating range of the sensor is 0.0 kPa to 111 kPa (0.0 psi to 16 psi). The ECM calibrates the sensor within the first five seconds after power is applied to the ECM. The ECM checks the sensor value against an acceptable pressure range. If the pressure value is not in this range, the previous calibration will be used. A manual calibration of the sensor should be done if the sensor or the ECM has been replaced. Refer to the calibration procedure Troubleshooting, "Analog Sensor - Calibrate".

Turbocharger Compressor Outlet Pressure Sensor - The sensor is used to obtain boost pressure. Boost pressure is used to control the ratio of fuel to air during acceleration. The ECM limits the amount of fuel that is injected, based upon inlet manifold pressure. Information in the ECM defines the relationship between the manifold pressure and the fuel ratio control limit (FRC). The operation is similar to the fuel ratio control on an engine with a mechanical governor. The sensor output is a DC voltage between 0.2 VDC and 4.8 VDC that varies with turbocharger outlet pressure. The operating range of the sensor is 0.0 kPa to 452 kPa (0.0 psi to 65 psi). The ECM calibrates the sensor within the first five seconds after power is applied to the ECM. The ECM checks the sensor value against an acceptable pressure range. If the pressure value is not in this range, the previous calibration will be used. A manual calibration of the sensor should be done if the sensor or the ECM has been replaced. Refer to the calibration procedure Troubleshooting, "Analog Sensor - Calibrate".

Atmospheric Pressure Sensor - The sensor is used to provide an atmospheric pressure signal to the ECM. If the Atmospheric Pressure Sensor should fail, the Right Turbocharger Compressor Inlet Pressure Sensor is used as a substitute. If the Right Turbocharger Compressor Inlet Pressure Sensor should fail, the Left Turbocharger Compressor Inlet Pressure Sensor is used as a substitute. The sensor output is a DC voltage between 0.2 VDC and 4.8 VDC that varies with atmospheric pressure. The operating range of the sensor is 0.0 kPa to 111 kPa (0.0 psi to 16 psi). The sensor is used to calibrate the other pressure sensors within the first five seconds after power is applied to the ECM. The ECM checks the sensor value against an acceptable pressure range. If the pressure value is not in this range, a diagnostic message will be generated and the engine may be derated. A manual calibration of the sensor should be done if the sensor or the ECM has been replaced. Refer to the calibration procedure Troubleshooting, "Analog Sensor - Calibrate".

Crankcase Pressure Sensor - The sensor is used in conjunction with the Atmospheric Pressure Sensor to determine if the engine crankcase pressure is too high. The Atmospheric pressure is subtracted from the Absolute crankcase pressure. The difference between the Atmospheric pressure and the Absolute crankcase pressure is the Differential Crankcase Pressure. The sensor output is a DC voltage between 0.2 VDC and 4.8 VDC that varies with crankcase pressure. The operating range of the sensor is 0.0 kPa to 111 kPa (0.0 psi to 16 psi). The ECM calibrates the sensor within the first five seconds after power is applied to the ECM. The ECM checks the sensor value against an acceptable pressure range. If the pressure value is not in this range, the previous calibration will be used. A manual calibration of the sensor should be done if the sensor or the ECM has been replaced. Refer to the calibration procedure Troubleshooting, "Analog Sensor - Calibrate".

Illustration 1	g00919938

Test Step 1. Check for Connector Damage.

1. Turn the battery disconnect switch to the OFF position.

2. Turn the keyswitch 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 for pinch points.

Expected Result:

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

Results:

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

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

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

  Stop.

Test Step 2. Check the Harness for Shorts.

1. Disconnect ECM connector J1/P1. Disconnect all of the analog sensors.

2. Measure the resistance between the analog supply P1-36 and the analog return P1-30.

3. Measure the resistance between the analog supply P1-36 and the engine ground.

4. Measure the resistance between the analog return P1-30 and the engine ground.

Expected Result:

The resistance should be more than 20,000 Ohms for each measurement.

Results:

• OK - The resistance is greater than 20,000 Ohms. Proceed to test step 3.

• Not OK - The resistance is less than 20,000 Ohms.

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

  Stop.

Test Step 3. Check the Analog Sensor Supply Voltage at the ECM.

1. Remove wire P1-36 from the ECM connector. Install a jumper wire into the socket for P1-36.

2. Remove wire P1-30 from the ECM connector. Install a jumper wire into the socket for P1-30.

3. Reconnect ECM connector J1/P1.

4. Turn the battery disconnect switch to the ON position.

5. Turn the keyswitch to the ON position. The engine should be off.

6. Measure the voltage between the analog supply P1-36 and the analog return P1-30.

7. Turn the keyswitch to the OFF position.

8. Remove the jumper wires and reconnect P1-36 and P1-30.

Expected Result:

The supply voltage should be 5.0 ± 0.2 VDC.

Results:

• OK - The supply voltage is 5.0 ± 0.2 VDC. The analog sensor supply is producing the correct voltage. Proceed to test step 4.

• Not OK - The supply voltage is not 5.0 ± 0.2 VDC. The analog sensor supply is not producing the correct voltage.

  Repair: Perform the diagnostic functional test Troubleshooting, "Electrical Power Supply".

  Stop.

Test Step 4. Check the Analog Sensor Supply Voltage at the Sensor Connector.

1. Turn the keyswitch to the ON position. The engine should be off.

2. Measure the voltage between socket A and socket B on the harness side of all analog sensor connectors. Ensure that you are measuring on the harness side of the connector since the sensors are disconnected.

Expected Result:

The supply voltage should be 5.0 ± 0.2 VDC.

Results:

• OK - The supply voltage is 5.0 ± 0.2 VDC. The supply voltage is reaching all the analog sensor connectors. Proceed to test step 5.

• Not OK - The supply voltage is not 5.0 ± 0.2 VDC. The supply voltage is not reaching all the analog sensor connectors. There is an open circuit in the harness or connectors.

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

  Stop.

Test Step 5. Check the Analog Sensors for Shorts.

1. Connect the analog sensor. Check the voltage at the sensor between socket A and socket B. Repeat this step for all of the analog sensors.

2. Turn the keyswitch to the OFF position.

Expected Result:

The supply voltage should be 5.0 ± 0.2 VDC after each analog sensor is connected.

Results:

• OK - The supply voltage is 5.0 ± 0.2 VDC after each analog sensor is connected. The analog supply voltage is correct when all of the sensors are connected. The analog sensor supply and the harness are okay.

  Repair: If the problem is intermittent, perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".

  Stop.

• Not OK - The supply voltage is not 5.0 ± 0.2 VDC after each analog sensor is connected. The voltage is okay before the sensor is connected. The voltage is not okay after the sensor is connected. The sensor may be internally shorted.

  Repair: Temporarily replace the sensor. Verify that the new sensor solves the problem before permanently installing the new sensor.

  Stop.