09/07/25, 11.12 SIS 2.
2024/08/27 Sensor Signal (Analog, Passive) - Test (UENR5825-01)
SMCS - 1439 i10269151
Machine ECM
PSP
The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the passive analog sensors of the machine.
202 -000A
Table 1
Diagnostic Trouble Codes for Machine ECM (MID J1939 299 - CDL 39)
J1939 CDL
- 96-3
5
04: /07/0 D5A
Diagnostic Trouble Code Description
Fuel Level Sensor: Voltage Above Normal
System Response
Fuel level display is disabled.
- 96-4
177-
1 2
UE :07+
Fuel Level Sensor: Voltage Below Normal
9 D Fuel level display is disabled.
Transmission Oil Temperature Sensor: Voltage Above The code is logged. The ECM detects voltage that is not in the
N
-
© 2 R58 07:00
3 Normal acceptable range.
177- Transmission Oil Temperature Sensor: Voltage Below The code is logged. The ECM detects voltage that is not in the
025 25
-
4 Normal acceptable range.
600- Hydraulic Oil Temperature Sensor: Voltage Above The code is logged. The ECM detects voltage that is not in the
Cat
-
3 Normal acceptable range.
-
600-
erp
Hydraulic Oil Temperature Sensor: Voltage Below The code is logged. The ECM detects voltage that is not in the
illa
4 Normal acceptable range.
r In
826- Torque Converter Oil Temperature Sensor: Voltage The code is logged. The ECM detects voltage that is not in the
-
3 Above Normal acceptable range.
-
826-
4
Torque Converter Oil Temperature Sensor: Voltage
Below Normal c. The code is logged. The ECM detects voltage that is not in the
acceptable range.
Possible causes for an FMI 3 Diagnostic code are:
The power supply circuit for the sensor is open.
The return circuit is open.
The signal circuit is open or the sensor is disconnected.
The signal circuit is shorted to the sensor power supply.
Wire harness shorted to supply voltage
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 for the sensor is shorted to ground.
The sensor has failed.
The ECM has failed. An ECM failure is unlikely.
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Illustration 1 g03
Schematic of the passive analog sensors
Note: The diagram above is a simplified schematic of the connections for the passive analog sensors. The schematic is electrically
correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the electrical schematic for the
specific machine being serviced for the complete schematic.
Reference: For D5R2 models (S/N: R5A1-UP) (S/N: R5L1-UP)refer to the latest revision of Electrical Schematic, UENR4123 for the
complete schematic.
Reference: For D5R2 models (S/N: WRE1-UP) (S/N: WDZ1-UP)refer to the latest revision of Electrical Schematic, UENR6987 for the
complete schematic.
Reference: For D6R2 models, refer to the latest revision of the Electrical Schematic, UENR4113 for the complete schematic.
Diagnostic Trouble Code Procedure
Table 2
Required Tools
Tool Part Number Description Qty
237-5130 Digital Multimeter Group 1
8T-3224 Needle Tip Group 1
T1
7X-1710 Multimeter Probe Group 1
8T-8726 Cable Assembly (Three Pin) (3-Pin Breakout) 1
JERD2129 Cat® Electronic Technician (ET) 1
T2 Windows-based PC 1
538-5051 Communication Adapter Gp 1
T3 6V-4148 Connector Repair Kit (Sure Seal) 1
T4 190-8900 Connector Field Repair Kit (Deutsch) 1
T5 175-3700 Connector Repair Kit Deutsch DT 1
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. Check the wiring
harness for pinch points or abrasions. Look for and repair areas that indicate wires are exposed. If a problem with a connection is found,
correct the problem and verify that the DTC is active before performing a troubleshooting procedure.
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1. Identify the active FMI associated with the DTC.
2. After determining which FMI is present, use the list below to determine which procedure to follow:
FMI 3, proceed to "FMI 3".
FMI 4, proceed to "FMI 4".
FMI 3
Table 3
Check The Sensor
Troubleshooting Test Steps Values Results
Result: The resistance readings agree
with the values in the table.
Note: Refer to the tables above for a list of
resistance values related to specific values.
Proceed to "Check For An Open In The
Sensor Circuit" Table 4.
1. Turn the key start switch and the disconnect
switch to the OFF position.
The resistance reading agrees with Result: The resistance readings do not
the values from the table. agree with the values in the table.
2. Disconnect the sensor from the harness.
Repair: Replace the sensor.
3. Measure the resistance between pin 1 and 2 of
the sensor.
Proceed to "Check If The Diagnostic Code
Remains" Table 6.
Table 4
Check For An Open In The Sensor Circuit
Troubleshooting Test Steps Values Results
1. The key start switch and disconnect switch remain in the
Result: The resistance is less than 5 Ω.
OFF position.
Proceed to "Check The Signal Circuit For A
2. The harness connector remains disconnected from the
Short" Table 5.
sensor.
Result: The resistance is greater than 5 Ω. The
3. At the sensor harness connector, install a jumper wire The resistance reading
open is in the signal circuit or the return circuit.
across pins 1 and 2. is less than 5 Ω.
Repair: Repair or replace the harness.
4. Disconnect the J1 and J2 connectors from the ECM.
Proceed to "Check If The Diagnostic Code
5. At the ECM harness connector, measure the resistance
Remains" Table 6.
between the signal and return contacts for the sensor.
Table 5
Check The Signal Circuit For A Short
Troubleshooting Test Steps Values Results
1. The disconnect switch and the key start switch Result: Each measurement is greater than 5K Ω.
remain in the OFF position. Each resistance
reading is greater Proceed to "Check If The Diagnostic Code Remains"
2. The harness connectors J1 and J2 remain than 5K Ω. Table 6.
disconnected from the ECM.
Result: A resistance measurement is less than 5 Ω. A
3. Remove the jumper wire from the sensor harness short exists between the signal circuit and the circuit
connector. with the low resistance measurement.
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4. At the ECM harness connectors, measure the Repair: Repair or replace the machine harness.
resistance between the signal circuit and all the other
contacts that are used on the ECM. Proceed to "Check If The Diagnostic Code Remains"
Table 6.
Table 6
Check If The Diagnostic Code Remains
Troubleshooting Test Steps Values Results
Result: The diagnostic code does not exist at this time. The initial
1. Reconnect all harness connectors. diagnostic code may have been caused by poor electrical connection or
Return machine to normal operating short at one of the harness connections. Resume machine operation.
condition.
STOP.
2. Turn the key start switch and the
disconnect switch ON. Result: The diagnostic trouble code has not been corrected. If the
diagnostic code has not been corrected after performing the procedure a
3. Clear all diagnostic codes. The diagnostic second time, the ECM may require replacement.
code is no longer
4. Operate the machine. present. Prior to replacing the ECM, always contact the Technical Communicator at
your dealership for possible consultation with Caterpillar. This consultation
5. Stop the machine and engage the may effect repair time.
safety lock lever.
Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to
6. Check if the diagnostic code is be replaced.
active.
STOP.
FMI 4
Table 7
Check The Sensor
Troubleshooting Test Steps Values Results
Result: Diagnostic code remains active.
1. Turn the key start switch and
disconnect switch ON.
Proceed to "Check The Wiring Harness Of The Sensor For A
Short To Ground" Table 8.
2. Ensure that the diagnostic code is
active. The diagnostic code
Result: Diagnostic code is no longer active.
remains active.
3. Disconnect sensor from machine
Repair: Replace the sensor.
harness.
Proceed to "Check If The Diagnostic Code Remains" Table 9.
Table 8
Check The Wiring Harness Of The Sensor For A Short To Ground
Troubleshooting Test Steps Values Results
1. Turn the key start switch and the disconnect Result: All resistance readings are greater than 5K Ω.
switch OFF. Each reading
greater than Proceed to "Check If The Diagnostic Code Remains" Table 9.
2. Disconnect the machine harness connector 5K Ω.
from the sensor. Result: One or more of the readings are less than 5 Ω. A short exists
between the signal contact and the circuit with the low resistance.
3. Disconnect the machine harness connectors
from the ECM. Repair: Repair or replace the machine harness.
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4. At the ECM harness connectors, measure the Note: A resistance that is greater than 5 Ω but less than 5K Ω would
resistance between the signal circuit and all the indicate a loose connection or a corroded connection in the circuit. A
other contacts that are used on the ECM. resistance measurement that is greater than 5K Ω would indicate an
open in the circuit.
Proceed to "Check If The Diagnostic Code Remains" Table 9.
Table 9
Check If The Diagnostic Code Remains
Troubleshooting Test Steps Values Results
Result: The diagnostic code does not exist at this time. The initial
1. Reconnect all harness connectors. diagnostic code may have been caused by poor electrical connection or
Return machine to normal operating short at one of the harness connections. Resume machine operation.
condition.
STOP.
2. Turn the key start switch and the
disconnect switch ON. Result: The diagnostic trouble code has not been corrected. If the
diagnostic code has not been corrected after performing the procedure a
3. Clear all diagnostic codes. The diagnostic second time, the ECM may require replacement.
code is no longer
4. Operate the machine. present. Prior to replacing the ECM, always contact the Technical Communicator at
your dealership for possible consultation with Caterpillar. This consultation
5. Stop the machine and engage the may effect repair time.
safety lock lever.
Follow the steps in Troubleshooting, "ECM - Replace" if the ECM needs to
6. Check if the diagnostic code is be replaced.
active.
STOP.
PSP-000AD5AD
2025/07/09
04:11:44+07:00
i05879868
© 2025 Caterpillar Inc.
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