CYLINDER AS-TILT & TIP 1407426 - Caterpillar

Possible causes for an FMI 3 diagnostic code are:
The relay has failed.
The signal circuit in the machine harness is shorted to the +battery.
The ECM has failed. An ECM failure is unlikely.Possible causes for an FMI 5 diagnostic code are:
The supply circuit is open.
The return circuit is open.
The relay has failed.
The ECM has failed. An ECM failure is unlikely. Possible causes for an FMI 6 diagnostic code are:
The energize circuit is shorted to ground.
The relay has failed.
The ECM has failed. An ECM failure is unlikely.
Illustration 1 g03856110
Schematic of the Relay CircuitsNote: The diagram above is a simplified schematic of the Power Train ECM and the Relay 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 the complete schematic:Reference(PL72 HRC) Electrical System Schematic, UENR5939Reference(PL72 LRC) Electrical System Schematic, UENR5940Reference(PL83 HRC) Electrical System Schematic, UENR4145Reference(PL83 LRC) Electrical System Schematic, UENR4146Reference(PL87 HRC) Electrical System Schematic, UENR4145Reference(PL87 LRC) Electrical System Schematic, UENR4146Diagnostic 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 2
Troubleshooting Test Steps    Values    Results    
1. Identify Active FMI Code Associated With Relay Circuit    
Code present.     FMI 3 diagnostic code, proceed to Test Step 2.
FMI 5 diagnostic code, proceed to Test Step 3.
FMI 6 diagnostic code, proceed to Test Step 5.    
Begin Process For FMI 3 Troubleshooting HERE    
2. Check The Machine Harness For A Short
A. Turn key start switch and disconnect switch OFF.
B. Disconnect the harness connection at the relay.
C. At the machine harness connector for the ECM. Measure the resistance from the signal contact to all contacts that are used in the machine harness connectors for the ECM.    
Each resistance measurement is greater than 5KΩ.     OK - All resistance measurements are greater than 5K Ω.
Proceed to Test Step 7.
NOT OK - One or more readings are less than 5 Ω.
Repair: A short exists between the signal contact and the circuit with the low resistance. Repair or replace the machine harness.
Proceed to Test Step 7.    
Begin Process For FMI 5 Troubleshooting HERE    
3. Check The Relay
A. Key start switch and disconnect switch OFF.
B. Disconnect the relay from the wiring harness.
C.Place a jumper wire between the signal contact and the return contact of the relay.
D. Turn the key start switch and the disconnect switch ON. Do not start the engine.
E. As the jumper is removed and connected to the contacts, observe any code change.    
The DTC remains active.     OK - The DTC remains