TANK GP-HYDRAULIC 2792575 - Caterpillar

Transmission/Chassis ECM
Use this procedure to troubleshoot the list of codes associated with the Transmission/Chassis ECM.
Table 1
Transmission/Chassis ECM (MID 27)
DTC Description System Response
1046-3 Power train Oil Filter Bypass Switch : Voltage Above Normal All transmission commands are still functional.
3916-3 Brake Charge Pump Filter Bypass Switch : Voltage Above Normal All transmission commands are still functional. Implement ECM
Use this procedure to troubleshoot the list of codes associated with the Implement ECM.
Table 2
Implement ECM (MID 82)
DTC Description System Response
3917-3 Cushion Hitch and Implement Pilot Supply Filter Bypass Switch : Voltage Above Normal All implement commands are still functional.
3918-3 Elevator Charge Pump Filter Bypass Switch : Voltage Above Normal All implement commands are still functional. 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 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 this diagnostic code is active before performing a troubleshooting procedure.Possible Causes for an FMI 3 Diagnostic code are:
The ground source is bad.
The signal is permanently open.
The switch has failed.
The ECM has failed. A failure of the Transmission/Chassis ECM is unlikely.
Illustration 1 g03351371
Schematic of the J1 and J2 Condition Switch connections for the Transmission/Chassis ECM.
Illustration 2 g03351233
Schematic of the J2 Condition Switch connections for the Implement ECM.
Note: The diagrams above are simplified schematics of the ECM connections. 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 your specific machine. Refer to the list below to identify the correct schematic for your machine.
Electrical Schematic, UENR2689 for the 621H Tractor/Scraper.
Electrical Schematic, UENR2690 for the 623H Tractor/Scraper.
Electrical Schematic, UENR2691 for the 627H Tractor/Scraper.Troubleshooting Procedure
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.Note: Poor harness connections are often the cause of a problem in electrical circuits. Before performing any troubleshooting 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 for nicks or abrasion. If a problem is found with any of the connections: correct the problem and verify that diagnostic code is still active, before performing the following procedures. For more information, refer to Troubleshooting, "Electrical Connector - Inspect".
Table 3
Troubleshooting Test Steps Values Results
1. Identify Active FMI Code Associated With Sensor Circuit
Code present. FMI 3 diagnostic code, proceed to Test Step 2.
Begin Process For FMI 3 Troubleshooting HERE
2. Check the Harness For an Open
A. Turn key start switch and disconnect switch OFF.
B. Disconnect the machine harness connectors from the switch