O-RING 025C 0951888 - Caterpillar

Illustration 1 g00656775
Schematic of the circuit for the engine overspeed protectionThis diagnostic code is recorded when the implement ECM reads the voltage of both circuits for engine overspeed protection as above normal.The possible causes of this diagnostic code are listed:
Both circuits in the harness are open.
The ECM has failed. This is unlikely.System Response:The machine response is listed:
The feature of engine overspeed protection may not function properly.Note: Ensure that CID 1395 FMI 03 is active.Test Step 1. CHECK THE CIRCUITS FOR AN OPEN.
Use the following table to aid in troubleshooting the circuit.
Table 1
STATUS OF THE CIRCUITS FOR THE IMPLEMENT ECM    
OVERSPEED SIGNAL
(918-OR)     OVERSPEED PARITY SIGNAL
(919-GN)     CONDITION    
Open/Shorted High     Ground     Normal    
Ground     Open/Shorted High     Overspeed    
Ground     Ground     CID 1395 FMI 04    
Open/Shorted High     Open/Shorted High     CID 1395 FMI 03    
Turn the key start switch and the disconnect switch to the OFF position.
Engine ECM: Disconnect the J1 machine harness connector from