SHAFT-PLANETARY 3T3079 - Caterpillar

Machine ECM
The following is a list of diagnostic codes (SPN) that are associated with the switch circuits of the machine.
Table 1
Machine ECM (MID 39)
SPN-FMI Code Description System Response
70-2 Parking Brake Switch : Erratic, Intermittent, or Incorrect Disable Propel, Steering, and Vibe
Fault Level - 3
1714-2 Operator Seat Direction Switch : Erratic, Intermittent, or Incorrect Disable Propel, Steering, and Vibe
Fault Level - 3
1714-14 Operator Seat Direction Switch : Special Instructions Disable Propel, Steering, and Vibe
Fault Level - 3 Possible causes for an FMI 2 Diagnostic code are:
The wire is intermittently shorted to the ground circuit while the machine is in operation.
The wire is intermittently shorted to + battery.
An intermittent open circuit exists.
The ECM has failed. ECM failure is unlikely.
Illustration 1 g03828491
Schematic of the switch circuits
Note: The diagram above is a simplified schematic of the Machine ECM connections. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of Electrical Schematic, UENR6464 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. 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.
Identify the active FMI code associated with the components.
Determine which code is present and use the list below to determine which procedure to follow.
FMI 2 diagnostic code, proceed to Table 2.
Table 2
FMI 2 Troubleshooting
Troubleshooting Test Steps Values Results
1. Check The Harness
A. Turn the disconnect switch and the key start switch OFF.
B. Inspect all harness connections. Make sure that the connectors are clean and tight.
C. Check the connectors for proper mating. Ensure that all the seals are present and in place.
D. Check the harness for signs of damage or abrasion.
E. Check the wires at the connector. Ensure that the wires are secured tightly into the connector. Take care not to pull the wire out of the connector.
F. Check the exposed wires at the connectors for nicks or signs of abrasion.
G. Check for moisture inside the connector.
The machine harness connectors are tight and free of corrosion. OK - The machine harness connectors are tight and free of corrosion.
Proceed to Test Step 2.
NOT OK - The machine harness connectors are in need of repair.
Repair: Repair or replace the machine harness.
Proceed to Test Step 3.
2. Check The Harness For An Open
A. Turn the key start switch and the disconnect switch to the OFF position.
B. Disconnect the machine harness connector from the switch.
C. Disconnect the machine harness connectors from the ECM.
D. At the harness connector for the switch, place a jumper wire