350G No high speed travel

[DozerPlowBoy]

1FF350GXPDE809407
Machine was unfortunately either vandalized or damaged by animal. Engine harness had to be replaced. This resolved all issues except high speed travel and the rear camera. Camera is least of concern. Need help on how to troubleshoot HS travel function. Which manual, schematic or otherwise should I start with? I can't find anything obvious like cut wire's etc.
Thank you

 

[ohdeereme]

A few things have to be working and reading in the correct range for high speed propel to function. Both pump discharge pressure sensors have to be reading and pressure must be less than 1500psi , both pump control pressure sensors have to be reading higher than 2.25mpa for the controller to energize the speed change solenoid. I'm not sure on the exact pressure specs but most of the time one or more of the pump discharge or control pressure sensors won't be reading and broken wires around the pumps will be the cause. You can monitor pressures on the monitor by holding down on the number ''9'' and pressing the large rotary button on top of the control panel. You'l have to scroll around in the menu until you find ''service menu '' then press the large button to enter. I'll try to post a picture of the menu structure if I can . I hope this helps, I've lost a lot of my tech. info and need to get it back.

 

[ExcavatorPartsVincent]

Since this started after the engine harness replacement, I would stay electrical/controller first before condemning travel motors or pumps.
The service-menu pressure check above is a good first step. I would also do these in order:
1. Pull active and stored codes, then watch live values for both pump discharge pressure sensors and pump control pressure sensors with key on, idle and travel commanded.
2. Find the high-speed travel/speed-change solenoid at the valve block. Check coil resistance, connector condition, and whether the controller sends voltage when high speed is selected.
3. Back-probe continuity from controller to the speed-change solenoid and to the pump pressure sensors. With animal/vandal damage, I would not trust a wire just because the outside insulation looks okay near a clamp or bend.
4. Compare left/right pressure sensor readings. One dead or out-of-range sensor can make the controller inhibit high speed even if low-speed travel feels normal.
5. Since the rear camera is also still dead, check any shared fuse, power feed, ground point, CAN/monitor connector or branch of the new harness. A missed ground or wrong pin in the replacement harness could explain two remaining electrical functions.
For manuals, I would want the Deere 350G technical manual plus the electrical schematic pages for the monitor, main controller, pump control sensors and travel speed solenoid. The hydraulic manual helps later, but I would start with the harness pinout and live sensor values.

 

[Diesel Dave]

In addition to the pump discharge and control pressure conditions mentioned in the 2 posts above , add to the high speed travel activation conditions list,
- Travel pressure sensor is sensing pressure (travel function actuated) .
- Front attachment pressure sensor not sensing pressure (no swing or dig functions actuated).
If the auto idle system is working correctly when using propel and any dig or swing function , the travel and front attachment pilot pressure sensors are good.

 

[Zewnten]

Dows the rabbit? or another indicator appear on the console but speed doesn't change or does it not appear at all?

 

[DozerPlowBoy]

Indicator does appear on the console but no speed change. Checked all 4 sensors on the pumps - no reading. Seems unlikely to have all sensors failed at once. Checked continuity to all sensors- good.

 

[Diesel Dave]

Checked all 4 sensors on the pumps - no reading. Seems unlikely to have all sensors failed at once. Checked continuity to all sensors- good.

I assume you have service codes for these 4 pump pressure sensors and possibly more ?
Did you check for continuity back to the main controller (MCZ) ?
If so , then check for 5.0 volts DC at the 2 outside pins of the wire harness to the individual pump pressure sensors.

 

[DozerPlowBoy]

I have checked for voltage at the outside pins of the pump sensors and have 5v at only one of the connectors. I do have continuity to the main controller.

 

[Diesel Dave]

I have checked for voltage at the outside pins of the pump sensors and have 5v at only one of the connectors. I do have continuity to the main controller.

Which of the pump sensors has the 5 volts at the connector ?
Strange you have continuity back to the main controller on all (4) pump sensor wiring but 5 volts available only at one of the sensors. Must be a 5 volt supply wire or a ground wire in the “ pump wiring harness “ that is in poor condition and won’t carry any load.
See portion of pump sensors wiring schematic below.