Got a D6T that I’m working on prefix is DTD throwing an event code E281-2 saying steering hydraulic filter plugged replaced filter no change I’m reading on sis that code gets thrown when the switch sees 105 Fahrenheit it’s not making a whole lot of sense to me because it shares the same oil as the hydraulic system and the hydraulic oil can get up to 200 Fahrenheit before throwing a code the switch on the filter housing is a normally closed switch when I bypass the switch no code so powertrain controller and wiring are good I ran the machine around and temp gunned the filter housing it was at 115-120 same as the hydraulic system any help would be appreciated thanks
Not quite correct. The switch has a temperature dependency of 105DegF so if the contacts open when the hydraulic oil temp is below that the plugged filter warning will not sound.
If you bypassed the switch and the E281 did not appear after that then doesn't that suggest that the switch is bad.? As you say it is an NC switch so it sounds the alarm when the contacts open. If it has somehow failed with the contacts open then as soon as the oil temperature hits 105 DegF after the tractor has been started from cold the alarm should go off.
Yea I have a switch ordered the circuit just wasn’t making sense to me I misunderstood the temperature dependency
The temperature dependency is designed into the electronics so that if the filter happens to go into bypass when the oil is really cold (always a possibility) then there will be no "nuisance alarm" for a plugged filter.