KIT-SEAL 2100179 - Caterpillar

Transmission ECM
The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the sensor supply of the machine.
Table 1
Transmission ECM (MID 27)
DTC Description System Response
41-03 8 VDC Supply: Voltage Above Normal Sensors powered by the 8 VDC supply will not function properly.
41-04 8 VDC Supply: Voltage Below Normal Sensors powered by the 8 VDC supply will not function properly.
262-03 5 VDC Sensor Power Supply: Voltage Above Normal Sensors powered by the 5 VDC supply will not function properly.
262-04 5 VDC Sensor Power Supply: Voltage Below Normal Sensors powered by the 5 VDC supply will not function properly. The diagnostic codes listed above are recorded when the interface module indicates that the voltage of the sensor supply circuit is too high, too low, or erratic.Possible causes of an FMI 03 Diagnostic code are:
The output of the sensor supply has shorted to the +Battery circuit.
The Implement ECM has failed (unlikely).Possible causes of an FMI 04 Diagnostic code are:
The output of sensor supply has an open circuit.
A sensor has failed.
The ECM has failed (unlikely).Note: Bad harness connections are often the cause of problems in electrical circuits. Before performing this procedure, inspect all of the connectors involved in the circuit. Verify that all of the connections in the circuit are dry, clean, secure, and in good condition. Each pin and socket in the connectors should mate correctly when the connectors are fastened together. Check for exposed wires at the connectors. Check wires for nicks or abrasions. If a problem is found with any of the connections, correct the problem and verify that the diagnostic code is still active before performing the following procedures.Use Cat® Electronic Technician (Cat ET) Service Tool to perform a wiggle test on the sensor circuit of the machine wiring harness. The wiggle test can be used to detect open or shorted connections in the machine wiring harness. Reconnect all harness connectors. Make sure that the connectors are fully seated. Make sure that the clips for each connector are fastened. For more information, refer to Troubleshooting, "Electrical Connector - Inspect".
Illustration 1 g03171297
Transmission ECM Sensor Supply and Return Contacts.
Note: The diagram above is a simplified schematic of the Transmission ECM connections. The diagram is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic, UENR3186 for the complete schematic.Diagnostic Trouble Code Procedure
Note: Before performing this procedure, verify that all circuit breakers and all fuses in the charging circuit and the ECM system supply circuit are closed. If a problem with a circuit breaker or a fuse is found, correct the problem and check for codes before proceeding with the following steps.
Table 2
Troubleshooting Test Steps Values Results
1. Identify The Active FMI Code Associated With The Sensor Supply Circuit
Code present FMI 03 diagnostic code, proceed to Test Step 2.
FMI 04 diagnostic code, proceed to Test Step 3.
2. Check The Harness For A Short To The +Battery Circuit
A. Turn the disconnect switch to the ON position.
B. For the +5 VDC