CASE 9P2679 - Caterpillar

Illustration 2 g03646397
Schematic of the Operator Control Switch (Switch to Battery) circuits
Note: The diagram above is a simplified schematic of the connections for the operator control switch (switch to battery) 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, UENR6729 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.
Table 4
Troubleshooting Test Steps Values Results
1. Identify Active FMI Code Associated With Sensor Circuit
Code present. FMI 2 diagnostic code, proceed to Test Step 2.
FMI 3 diagnostic code, proceed to Test Step 3.
FMI 4 diagnostic code, proceed to Test Step 5.
Begin Process For FMI 2 Troubleshooting HERE
2. Check The Harness
A. Turn the key start switch and disconnect switch OFF.
B. Inspect the harness.
C. Check for the proper mating
D. Check the exposed wires for nicks and abrasions.
E. Check for moisture, dirt, or corrosion.
F. Check the pin/socket for a proper fit. The harness appears to be correct. OK - The harness appears to be correct.
Proceed to Test Step 11.
NOT OK - The harness appears to be damaged.
Repair: Repair the machine harness or replace the machine harness.
Proceed to Test Step 11.
Begin Process For FMI 3 Troubleshooting HERE
3. Check The Circuit For A Short
A. Turn the key start switch and disconnect switch OFF.
B. Disconnect the switch from the machine harness.
C. Disconnect