ENGINE AR 8N2889 - Caterpillar

Machine ECM
The following code is associated with the engine speed dial related to the Machine ECM.
Table 1
Machine ECM (MID 299)
DTC Code Description System Response
586-12 Engine Speed Dial Switch : Bad device or component Cannot control engine speed. Possible causes for an FMI 12 Diagnostic code are:
The dial switch has failed.
The engine governor control has failed.
The CAN Data Link between the Switch Panel and the Machine ECM is working intermittently or has failed.
The machine harness to the dial switch or the governor control has failed.
The ECM has failed. This situation is unlikely.
Illustration 1 g03860086
Engine Speed (Governor control) schematic
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, M0094859 for 320D3 and M0094901 for 323D3 excavator electrical systems.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.
Table 2
Troubleshooting Test Steps Values Results
1. Check For An Active Diagnostic Code
A. Turn the key start switch to the ON position.
B. Use Cat ET to check for all active diagnostic codes.
B. Check for DTC 586-12.
C. Check for DTC 246-9 or DTC 246-19.
Diagnostic code CID 586 FMI 12 is active. OK - DTC 586-12 is active without either DTC 246-9 or DTC 246-19 being active.
Proceed to Test Step 2.
NOT OK - Diagnostic code DTC 586-12 AND DTC 246-9 or DTC 246-19 are active.
Repair: Follow the procedure for troubleshooting the code for the data link circuit.
Result: If DTC code 586-12 is no longer active, return the machine to service.
If, after troubleshooting the data link, DTC 586-12 is active, proceed to Test Step 2.
2. Inspect The Switch Panel Harness Connection
A. Turn the disconnect switch to the OFF position.
B. Inspect the harness connector making sure that the connector is clean and tight.
C. Check the connector for proper mating.
D. Check the connector. Ensure that the wires are secured tightly into the connector. Take care not to pull the wire out of the connector.
E. Check any exposed wires at the connector for nicks or signs of abrasion.
F. Check for moisture inside the connector.
G. Check the connector for dirty contacts or corroded contacts.
H. Check each pin and each socket of the switch panel harness connectors. Ensure that the contacts are properly installed. The contacts should mate correctly when the two pieces of the connector are placed together.
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 3.
NOT OK - The machine harness connectors are in need of repair.
Repair: Repair or replace the machine harness.
Proceed to Test Step 5.
3. Check The