BALLSTUD- 2659213 - Caterpillar

Illustration 1 g00896393
Schematic of the circuit of the temperature sender (hydraulic oil)
This diagnostic code is associated with the temperature sender for the hydraulic oil. An FMI 03 means the ECM has determined the sender signal output voltage is above normal. Possible causes for this diagnostic code are:
The sender has failed.
The sender is disconnected.
The signal output circuit of the sender is open.
The signal output circuit in the machine harness is shorted to a voltage source.
The ECM may have failed, but is unlikely. Test Step 1. CHECK THE SENDER, THE HARNESS, AND THE ECM.
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness connector from the hydraulic oil temperature sender.
At the machine harness connector for the sender, measure the DC voltage between the signal output contact 1