CAMSHAFT GP 4647004 - Caterpillar

Table 1
Diagnostic Trouble Codes for the ECM Main Relay    
J1939 Code     Description     Notes    
1485-7     ECM Main Relay : Not Responding Properly     The Electronic Control Module (ECM) detects that the battery supply voltage is still present 0.5 seconds after the shut-off request from the ECM.
The ECM is receiving battery voltage after the keyswitch has been turned OFF, which will drain battery power.    
1485-14     ECM Main relay : Special Instruction     The ECM requires battery voltage for up to 60 seconds after the keyswitch has been turned OFF.
A fault is caused when the ECM has lost battery voltage before this period has elapsed.
The fault is detected the next time the keyswitch is turned ON. The diagnostic code becomes active when the fault is detected for three consecutive starts.
This condition is most likely caused by shutting the engine down using the battery disconnect switch instead of the keyswitch for three consecutive shutdowns or using the battery disconnect switch immediately after the keyswitch has been turned OFF.    
2840-14     ECU Instance : Special Instruction     The ECM was unable to write data to the internal memory.
This condition is most likely caused by removing battery power from the ECM while the ECM was attempting to write data to the internal memory.    This engine uses the ECM main relay to supply 12 V to the ECM. The ECM enables this relay when the "Ignition Keyswitch" signal is detected on pin P1:54.The ECM requires battery voltage for up to 60 seconds after the keyswitch has been turned OFF in order to save data to the memory.The ECM will shut off the main relay after all data has been saved to the memory.
Illustration 1 g03603857
Schematic diagram for the ECM main relay
Illustration 2 g02716384
View of the pin locations on the P1 connector for the ignition keyswitch and battery supply circuit (1) Battery+ (2) Battery ground (3) Battery+ (4) Battery ground (5) Battery+ (6) Battery ground (28) ECM main relay (54) Ignition key switch
Table 2
Troubleshooting Test Steps    Values    Results    
1. Inspect Electrical Connectors and Wiring
A. Check the fuses.
B. Thoroughly inspect the P1/J1 ECM connectors and thoroughly inspect the connector for the ECM main relay. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a
30 N (6.7 lb) pull test on each of the wires that are associated with the main relay.
D. Check the harness for abrasion and for pinch points from the battery to the ECM, and from the relays to the ECM.
   
Damaged wire or connector    
Result: A damaged wire or damaged connector was found. A fuse is blown.
Repair the damaged wire or the damaged connector. Replace any blown fuses
Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly connected and/or inserted and the harness is free of corrosion, of abrasion or of pinch points.
Proceed to Test Step 2.
   
2. Check for Diagnostic Codes
A. Turn the keyswitch