VALVE GP-PUMP CONTROL 3681339 - Caterpillar

Transmission ECM
The following is a list of Diagnostic Trouble Codes (DTCs) that are associated with the sensor supply circuits of the machine.
Table 2
Transmission ECM (MID 81)
DTC Description System Response
41-3 8 VDC Supply: Voltage Above Normal Sensors powered by the 8 VDC supply will not function properly.
41-4 8 VDC Supply: Voltage Below Normal Sensors powered by the 8 VDC supply will not function properly.
262-3 5 VDC Supply: Voltage Above Normal Sensors powered by the 5 VDC supply will not function properly.
262-4 5 VDC Supply: Voltage Below Normal Sensors powered by the 5 VDC supply will not function properly.
1482-3 10 VDC Supply: Voltage Above Normal Sensors powered by the 10 VDC supply will not function properly.
1482-4 10 VDC Supply: Voltage Below Normal Sensors powered by the 10 VDC supply will not function properly. The diagnostic code is 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 3 Diagnostic code are:
The output of the sensor supply has shorted to the +battery circuit.
The ECM has failed. A failure of the ECM is unlikely.Possible causes of an FMI 4 Diagnostic code are:
The output of sensor supply has an open circuit.
A sensor has failed.
The ECM has failed. A failure of the ECM is unlikely.
Illustration 2 g03626939
Schematic of the Sensor Supply circuits
Note: The diagram above is a simplified schematic of the connections for the sensory supply circuits. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic, UENR3117 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. For sensors powered via the fuse panel, check the condition of the appropriate fuse before beginning the troubleshooting procedure.Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code, listed in the table above, is active before performing this procedure.
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 4.
Begin Process For FMI 3 Troubleshooting HERE
2. Check The Voltage At The ECM
A. Turn the key start switch and the battery disconnect switch to the OFF position.
B. At the machine harness connector for the ECM, insert a 7X-1710 Multimeter Probe along the contact for the sensor power. Insert another probe along the return contact for the sensor power.
C. Turn the disconnect switch to the ON position.
E. Observe the