320D3 GC Excavators Machine Electronic Control System Sensor Supply - Test Caterpillar


Sensor Supply - Test
`
1.1. Machine ECM
2.1. Diagnostic Trouble Code Procedure
3.1. FMI 3
4.1. FMI 4

Machine ECM

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

Table 1
Machine ECM (MID 299) 
J1939  CDL  Code Description  System Response 
  41-3  8 V Supply: Voltage Above Normal  Multiple failures of systems or components associated with this code. 
  41-4  8 V Supply: Voltage Below Normal  Multiple failures of systems or components associated with this code. 
  262-3  5 V Supply: Voltage Above Normal  Multiple failures of systems or components associated with this code. 
  262-4  5 V Supply: Voltage Below Normal  Multiple failures of systems or components associated with this code. 

The sensor supply is the voltage output originating from the electronic control module connections.



Illustration 1g06575524
Sensor Supply schematic

Note: The diagram above is a simplified schematic of the Machine ECM connections. The schematic is electrically correct. However, not all the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, M0116913 for 320D3 GC excavator electrical systems.

Diagnostic Trouble Code Procedure

Table 2
Required Tools 
Tool  Part Number  Description  Qty 
T1  146-4080(1)  Digital Multimeter Group 
8T-3224 Needle Tip Group 
7X-1710 Multimeter Probe Group 
8T-8726 Cable Assembly (Three Pin) (3-Pin Breakout) 
T2  JERD2129  Cat® Electronic Technician (Cat ET) 
Windows-based PC 
538-5051 Communication Adapter Gp 
T3  6V-4148  Connector Repair Kit (Sure Seal) 
T4  190-8900  Connector Field Repair Kit (Deutsch) 
T5  175-3700  Connector Repair Kit Deutsch DT 
(1) This multimeter can use an RS232C cable to connect to a Laptop computer or Dataview tool gp for troubleshooting.

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. For sensors powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.

  1. Identify the active FMI code associated with the components.

  2. Determine which code is present and use the list below to determine which procedure to follow.

  • FMI 3 diagnostic code, proceed to "FMI 3".

  • FMI 4 diagnostic code, proceed to "FMI 4".

FMI 3

Table 3
Check The Voltage At The Sensors 
Troubleshooting Test Steps  Values  Results 
1. Turn key start switch and disconnect switch ON.

2. Disconnect the machine harness connector for the sensors.

3. At the machine harness connector for the sensors, measure the voltage between the sensor supply contact and the sensor return contact. 
Voltage reading is correct for the sensors.  Result: The voltage reading is correct for the sensors.

Proceed to "Check If The Diagnostic Code Remains" Table 6.

Result: The voltage is greater than the supply for the circuit.

Proceed to "Check The Power Supply At The ECM" Table 4. 

Table 4
Check The Power Supply At The ECM 
Troubleshooting Test Steps  Values  Results 
1. Turn the key start switch and disconnect switch to the OFF position.

2. At the J1 harness connector for the ECM, use a 151-6320 Removal Tool to remove the supply wire and the sensor return wire. The harness connector remains connected to the ECM.

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

4. Use the multimeter probes to make contact on the connector pins. Measure the voltage at the ECM pins between the sensor supply contact and sensor return contact . 
Voltage reading is correct for the supply.  Result: The voltage is correct. The ECM power supply is correct. Install the wires and sockets that were removed from the ECM connector back into the original locations.

Proceed to "Check For A Short In the Harness" Table 5.

Result: The voltage measurement is greater than the supply voltage. The measurement is not correct. The ECM may have failed.

Proceed to "Check If The Diagnostic Code Remains" Table 6. 

Table 5
Check For A Short In the Harness 
Troubleshooting Test Steps  Values  Results 
1. The sensors remain disconnected from the machine harness.

2. The key start switch and disconnect switch remain in the OFF position.

3. Disconnect the machine harness connectors from the ECM.

4. At the ECM harness connector, measure the resistance between the supply contact and all the other contacts that are used for the ECM. 
Each resistance is greater than 5K Ω.  Result: Each resistance is greater than 5K Ω.

Proceed to "Check If The Diagnostic Code Remains" Table 6.

Result: One or more readings less than 5 Ω. There is a short between the signal contact and the circuit with the low resistance.

Repair: Refer to the complete electrical schematic. Examine all the connectors of the machine harness for possible short circuits. Repair or replace the machine harness.

Note: A resistance that is greater than 5 Ω but less than 5K Ω would indicate a loose connection or a corroded connection in the circuit. A resistance measurement that is greater than 5K Ω would indicate an open in the circuit.

Proceed to "Check If The Diagnostic Code Remains" Table 6. 

Table 6
Check If The Diagnostic Code Remains 
Troubleshooting Test Steps  Values  Results 
1. Reconnect all harness connectors. Return machine to normal operating condition.

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

3. Clear all diagnostic codes.

4. Operate the machine.

5. Stop the machine and engage the safety lock.

6. Check if the diagnostic code is active. 
The diagnostic code is no longer present.  Result: The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation.

STOP.

Result: The 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 the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time.

Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to be replaced.

STOP

FMI 4

Table 7
Check The Sensors 
Troubleshooting Test Steps  Values  Results 
1. Turn the key start switch and disconnect switch to the ON position.

2. Observe the status of the diagnostic code as each sensor is disconnected. 
The FMI 4 diagnostic code is no longer active when one of the sensors on the supply circuit is disconnected.  Result: The diagnostic code is not active when one of the sensors in the supply circuit is disconnected. The power supply circuit is correct.

Repair: Repeat this test step to determine the sensor that causes the problem. Replace the sensor that is causing the problem.

Proceed to "Check If The Diagnostic Code Remains" Table 10.

Result: The diagnostic code is still active. Disconnecting the sensors in the circuit did not affect the status of the diagnostic code.

Proceed to "Check The Signal Circuit For A Short To Ground" Table 8. 

Table 8
Check The Signal Circuit For A Short To Ground 
Troubleshooting Test Steps  Values  Results 
1. Turn the key start switch and the disconnect switch to the OFF position.

2. Disconnect the harness connectors from the ECM.

3. Measure the resistance between the power supply contact and frame ground.

4. Measure the resistance between the power supply contact and all the other contacts that are used for the ECM. 
Each resistance is greater than 5K Ω.  Result: Each resistance is greater than 5K Ω. The harness circuit is correct.

Proceed to "Check The Power Supply At The ECM" Table9.

Result: The resistance is less than 5 Ω. The power supply circuit is shorted to ground. The short circuit exists between the power supply circuit and the circuit with the low-resistance measurement.

Repair: Repair or replace the machine harness.

Proceed to "Check If The Diagnostic Code Remains" Table 10. 

Table 9
Check The Power Supply At The ECM 
Troubleshooting Test Steps  Values  Results 
1. Turn the key start switch and disconnect switch to the OFF position.

2. At the J1 harness connector for the ECM, use a 151-6320 Removal Tool to remove the supply wire and the sensor return wire. The harness connector remains connected to the ECM.

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

4. Use the multimeter probes to make contact on the connector pins. Measure the voltage at the ECM pins between the sensor supply contact and sensor return contact . 
Voltage reading is correct for the supply.  Result: The voltage is correct. The ECM power supply is correct. Install the wires and sockets that were removed from the ECM connector back into the original locations.

Proceed to "Check If The Diagnostic Code Remains" Table 10.

Result: The voltage measurement is less than the supply voltage. The measurement is not correct. The ECM has failed.

Proceed to "Check If The Diagnostic Code Remains" Table 10. 

Table 10
Check If The Diagnostic Code Remains 
Troubleshooting Test Steps  Values  Results 
1. Reconnect all harness connectors. Return machine to normal operating condition.

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

3. Clear all diagnostic codes.

4. Operate the machine.

5. Stop the machine and engage the safety lock.

6. Check if the diagnostic code is active. 
The diagnostic code is no longer present.  Result: The diagnostic code does not exist currently. The initial diagnostic code may have been caused by poor electrical connection or short at one of the harness connections. Resume machine operation.

STOP.

Result: The 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 the ECM, always contact the Technical Communicator at your dealership for possible consultation with AVSpare. This consultation may effect repair time.

Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to be replaced.

STOP

Information System:

320D3 GC Excavators Machine Electronic Control System Sensor Signal (PWM) - Test
320D3 GC Excavators Machine Electronic Control System Sensor Signal (Analog, Passive) - Test
320D3 GC Excavators Machine Electronic Control System Sensor Signal (Analog, Active) - Test
320D3 GC Excavators Machine Electronic Control System Relay - Test
320D3 GC Excavators Machine Electronic Control System Engine Speed Control - Test
Loader Calibration may Fail on Certain 432 and 444 Back Hoe Loaders {7000, 7490, 7610, 7620}
374 Hydraulic Excavator Machine Systems Cab - Remove and Install
910, 914 and 920 Compact Wheel Loader Power Train Axle (Rear) - Assemble
Caterpillar Switchgear Remote Access System Service Tool Tech-Link is Now Available for All Cat Generator Sets {7002, 7451, 7606, 7635}
320D3 GC Excavators Machine Electronic Control System CAN Data Link - Test
320D3 GC Excavators Machine Electronic Control System Alarm - Test
New Troubleshooting Procedure for Cat Product Link™ External Antenna is Now Available for Certain Machines {0374, 733B, 7606}
3512E Locomotive Engines Catalyst (SCR) - Install
320D3 GC Excavators Machine Electronic Control System Solenoid Valve - Test
320D3 GC Excavators Machine Electronic Control System Switch Circuits - Test
320D3 GC Excavators Machine Electronic Control System Window Wiper Delay - Test
320D3 GC Excavators Machine Electronic Control System Connector Contact Description
320D3 GC Excavators Machine Systems Specifications Stick Cylinder
320D3 GC Machine System Swing Motor - Disassemble
320D3 GC Machine System Swing Motor - Assemble
335 Hydraulic Excavator Machine Systems Blade - Remove and Install
335 Hydraulic Excavator Machine Systems Recoil Spring - Disassemble
335 Hydraulic Excavator Machine Systems Recoil Spring - Assemble
M314, M315, M316, M318, M319, and M320 Wheeled Excavator Machine System Calibrations (Cat ET)