816K Landfill Compactor and 815K Soil Compactor Systems Caterpillar

Sensor Supply - Test

Usage:

816K LT6

Transmission ECM

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the sensor power supply circuits of the machine.

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Table 1
Transmission ECM (MID 81)
DTC	Code Description	System Response
41-3	8 VDC Supply: Voltage above normal	Sensors powered by the 8 VDC supply may not function properly.
41-4	8 VDC Supply: Voltage below normal	Sensors powered by the 8 VDC supply may not function properly.
1482-3	10 Volt Sensor DC Power Supply: Voltage above normal	Sensors powered by the 10 VDC supply may not function properly.
1482-4	10 Volt Sensor DC Power Supply: Voltage below normal	Sensors powered by the 10 VDC supply may not function properly.

Possible causes for an FMI 3 diagnostic code are:

The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted to another circuit.
The signal circuit in the machine harness is open or the sensor is disconnected.
The sensor has failed.
The ECM has failed. An ECM failure is unlikely.

Possible causes for an FMI 4 diagnostic code are:

The signal circuit in the machine harness is shorted to ground.
The sensor has failed.
The ECM has failed. An ECM failure is unlikely.

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Illustration 1	g03891985
Schematic of the Transmission ECM Sensor Supply

Note: The diagram above is a simplified schematic of the Transmission ECM and the Sensor Supply connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision for the complete schematic.

Implement ECM

The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the sensor power supply circuits of the machine.

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Table 2
Implement ECM (MID 82)
DTC	Code Description	System Response
41-3	8 VDC Supply: Voltage above normal	Sensors powered by the 8 VDC supply may not function properly.
41-4	8 VDC Supply: Voltage below normal	Sensors powered by the 8 VDC supply may not function properly.
1482-3	10 Volt Sensor DC Power Supply: Voltage above normal	Sensors powered by the 10 VDC supply may not function properly.
1482-4	10 Volt Sensor DC Power Supply: Voltage below normal	Sensors powered by the 10 VDC supply may not function properly.

Possible causes for an FMI 3 diagnostic code are:

The sensor supply or the ground circuit in the machine harness is open.
The signal circuit in the machine harness is shorted to another circuit.
The signal circuit in the machine harness is open or the sensor is disconnected.
The sensor has failed.
The ECM has failed. An ECM failure is unlikely.

Possible causes for an FMI 4 diagnostic code are:

The signal circuit in the machine harness is shorted to ground.
The sensor has failed.
The ECM has failed. An ECM failure is unlikely.

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Illustration 2	g03841730
Schematic of the Implement ECM Sensor Supply

Note: The diagram above is a simplified schematic of the Implement ECM and the Sensor Supply connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision for the complete schematic.

Diagnostic Trouble Code Procedure

Note: Prior to beginning this procedure, inspect the harness connectors that are involved in this circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit are clean, secure, and in good condition. If a problem with a connection is found, correct the problem and verify that the diagnostic code is active before performing a troubleshooting procedure.

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Table 3
Troubleshooting Test Steps	Values	Results
1. Identify The Active FMI Code Associated With The Sensor Supply Circuit	Code present	FMI 3 diagnostic code, proceed to Test Step 2. FMI 4 diagnostic code, proceed to Test Step 5.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Supply Voltage A. Turn the key start switch and the disconnect switch OFF. B. At the harness connector, insert the positive multimeter probe along the supply positive contact. Insert the negative multimeter probe along the supply return contact. C. Turn the key start switch and the disconnect switch ON. D. Observe the voltage measurement.	The voltage measurement is in the range of 8.0 ± 0.5 VDC.	OK - The voltage measurement is in the range of 8.0 ± 0.5 VDC. Proceed to Test Step 9. NOT OK - The voltage measurement is greater than 8.0 ± 0.5 VDC. The power supply voltage is above normal. Proceed to Test Step 3.
3. Check The ECM Power Supply At The ECM With The Circuit Disconnected A. Turn the key start switch and the disconnect switch OFF. B. At the ECM harness connector, remove the power supply positive circuit from the connector body. C. Turn the key start switch and the disconnect switch ON. D. At the connector, measure the supply voltage with the circuits disconnected. Insert the multimeter probes at the positive contact and at the return contact. E. Measure the voltage.	The voltage measurement is in the range of 8.0 ± 0.5 VDC.	OK - The voltage measurement is in the range of 8.0 ± 0.5 VDC. The voltage is correct. Proceed to Test Step 4. NOT OK - The voltage measurement is greater than 8.0 ± 0.5 VDC. Proceed to Test Step 9.
4. Check For A Short A. Turn the key start switch and the disconnect switch OFF. B. Disconnect the harness connector from the sensor and ECM. C. At the harness connector for the ECM, measure the resistance between the power supply positive circuit at contact and each of the other individual circuit contacts that are used on the harness connector.	The resistance is greater than 4k Ω.	OK - The resistance is greater than 4k Ω. Proceed to Test Step 9. NOT OK - One or more of the resistance measurements is less than 4kΩ. There is a short circuit between a power supply circuit and another circuit in the machine harness. Repair: Repair or replace the machine harness. Proceed to Test Step 9.
Begin Process For FMI 4 Troubleshooting HERE
5. Check The Supply Voltage A. Turn the key start switch and the disconnect switch OFF. B. At the harness connector, insert the positive multimeter probe along the supply positive contact. Insert the negative multimeter probe along the supply return contact. C. Turn the key start switch and the disconnect switch ON. D. Observe the voltage measurement.	The voltage measurement is in the range of 8.0 ± 0.5 VDC.	OK - The voltage measurement is in the range of 8.0 ± 0.5 VDC. Proceed to Test Step 9. NOT OK - The voltage measurement is less than 8.0 ± 0.5 VDC. The power supply voltage is below normal. Proceed to Test Step 6.
6. Check The ECM Power Supply At The ECM With The Circuit Disconnected A. Turn the key start switch and the disconnect switch OFF. B. At the ECM harness connector, remove the power supply positive circuit from the connector body. C. Turn the key start switch and the disconnect switch ON. D. At the connector, measure the supply voltage with the circuits disconnected. Insert the multimeter probes at the positive contact and at the return contact. E. Measure the voltage.	The voltage measurement is in the range of 8.0 ± 0.5 VDC.	OK - The voltage measurement is in the range of 8.0 ± 0.5 VDC. The voltage is correct. Proceed to Test Step 7. NOT OK - The voltage measurement is greater than 8.0 ± 0.5 VDC. Proceed to Test Step 9.
7. Disconnect The Position Sensor A. Turn the key start switch and the disconnect switch ON. B. Disconnect the machine harness from the sensor. C. Check the status of the active diagnostic code.	The diagnostic code is no longer active.	OK - The diagnostic code is no longer active when the sensor is disconnected. The sensor has failed. Repair: Replace the sensor.. Proceed to Test Step 9. NOT OK - The problem appears to be in the cab harness. Proceed to Test Step 8.
8. Check For A Short A. Turn the key start switch and the disconnect switch OFF. B. Disconnect the harness connector from the sensor and ECM. C. At the harness connector for the ECM, measure the resistance between the power supply positive circuit at contact and each of the other individual circuit contacts that are used on the harness connector.	The resistance is greater than 4k Ω.	OK - The resistance is greater than 4k Ω. Proceed to Test Step 9. NOT OK - One or more of the resistance measurements is less than 4kΩ. There is a short circuit between a power supply circuit and another circuit in the machine harness. Repair: Repair or replace the machine harness. Proceed to Test Step 9.
9. Check If The Diagnostic Code Remains A. Inspect the harness connectors and clean the contacts of the harness connectors. B. Reconnect all harness connectors. C. Turn key switch and disconnect switch ON. D. Operate the machine. E. Check if diagnostic code is active.	Diagnostic code is no longer present.	OK - Diagnostic code does not exist at this time. Initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation. STOP NOT OK - Diagnostic trouble code has not been corrected. If the diagnostic code has not been corrected after performing the procedure a second time, the ECM may require replacement. Prior to replacing this component, always contact the Technical Communication at your dealership for possible consultation with Caterpillar. This consultation may greatly effect repair time. Follow the steps in Troubleshooting, "Electronic Control Module (ECM) - Replace" if the ECM needs to be replaced. STOP