I have a 2005 Deere 710g. Sometimes when I go to operate the machine, start it up the machine will start alarming showing the "stop" symbol, along with another warning symbol. When it is alarming, the tractor will not move in forward or reverse and the parking brake will be locked up because the rear wheels will be locked. It is showing a code "F9B0" (Parking brake switch closed) Sometimes, just waiting a second, the backhoe will stop alarming and will begin to operate normally. Sometimes you have to turn the machine off and start it right back up and it will be ok, and also sometimes you have to wait hours or days for it to work again. Or sometimes the machine will run fine for an hour, or just 2 minutes or not at all. So far what I am trying to get across is I have not found any correlation to temperature, time, machine being warm, bouncing around, etc. Also, while it does this, the seatbelt light will start illuminating off and on, and the RPM's will show as dashes. Also, when it has this trouble the hoe and loader arms will still function, just no forward or reverse. The auxillary hydraulics will also stop working when this trouble happens. So I tend to think its an electronic problem, not mechanical. ECM has been replaced, and the sensor / switch on top of the differential for the park brake has been replaced as well. Another observation I have made is that there are 2 sensors / brake pressure switches on the back of the valve block where the foot pedals for the service brake is connected to, and when I unplug one of them, it will replicate the problem exactly. So perhaps one of those sensors is bad? Any ideas greatly appreciated.
Moving forward when starting a thread please include the full machine serial number. . The warning indicator light below the park brake indicator light is for Low service brake pressure. Code FB9O refers to Service Brake Pressure Switches . To enter the Service Menu in the monitor, push and hold the MENU button for approximately 5 seconds until the monitor beeps. In service menu scroll and look for LIVE DATA SWITCH INPUT . Hit select. Scroll down look for SERVICE BRAKE PRESSURE (on or off) . With engine running , (assuming there is a minimum of 900 psi of brake pressure) both switches should show “Closed“ .
SN: T0710GX953430 I will look into the menu next time I am at the yard. Thanks.
So to update this thread, I was unable to fix the problem myself. Checked grounds and wires, didn't find anything. So I took the machine to the dealer. They told me they replaced a resistor and now the machine is running fine again... they also told me they figure the machine may have been flooded or stuck deep in a mud bog? Because there is rust under the cab. When I got the machine, I noticed the hour meter now shows 4,000 something, it used to be 1,000 something. I was always suspicious of the hours on this machine. How and why would a digital meter change after a visit to the dealer? This was a machine I bought from Ritchie Brothers sight unseen.
Well to revive an old thread, I am having the same problem today. Going into the menu and viewing live data when the machine is alarming and stopped it shows “service brake pressure on”.
It appears the (2) service brake pressure sensors are good and are reading more than 900 psi. I assume the dealer replaced a CAN resistor. Can you post a picture of the dealer invoice with the repair description and parts list.
I don’t have the paper work with me at the moment, but I don’t think what they did fixed the machine. Because shortly after the repair was made I was experiencing the same condition.
When the machine is operating correctly and the service brakes are not applied the display will show “service brake pressure off”. If you hold the service brake the display will show “service brake pressure on” and then switch back to “service brake pressure off” while you are still applying the service brakes.
Is service code FB9O still active intermittently ? The 2 service brake pressure sensors that code FB90 references are on the inlet to the brake valve. The service brake pressure switch referenced in the data list that turns on and off with brake pedal travel must be the brake light pressure switch.
Yes the code is still active intermittently. I am starting to think it’s the flex load controller (FLC). I removed it and cleaned the connections and I noticed the box looks slightly corroded.