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  1. M

    How do I test a decel sensor

    I have been working on a JD 450J (s/n T0450JX139324) and have had some help from this forum. Engine starts but won’t throttle up and won’t move. One suggestion is that the decel sensor may be stuck. I took some readings and didn’t see any changes as I depressed the pedal. Got a new sensor and...
    • Msh2
    • Thread
    • Replies: 0
    • Forum: Dozers
  2. M

    John Deere 450J wont move

    A little more testing on decel - I unplugged the wiring harness from the TCU and measured resistance across the pins and got no changes as I moved the brake pedal up and down.
  3. M

    John Deere 450J wont move

    Possibly I am taking these instructions out of context. These values are for recalibration and would possibly show up as voltages on the TCU screen.
  4. M

    John Deere 450J wont move

    I copied these from a post in October by @mg2361. I am trying to verify my voltages but can’t figure out where to take the readings. If I disconnect the cables from the Tcu then I lose my voltage. Unless I read the voltage on the unit but then I lose signal from decel. Decel pedal voltages...
  5. M

    John Deere 450J wont move

    Throttle dial measurement were 350 ohms at low idle and 650 ohms at high idle.
  6. M

    450J manuals

    Thanks for the reference.. I need all the help I can get.
  7. M

    John Deere 450J wont move

    Thank you. Just got your message. All the fuses are good. Grounding strap has been removed and polished.
  8. M

    John Deere 450J wont move

    I’ve cleared all the diag codes from the monitor display, turned key off and then restarted engine. The only codes left were F9C3 and F423. The TCU display was unresponsive. I pressed and held each of the buttons on the unit and could get no response. It just kept flashing RTOS and !APP.
  9. M

    John Deere 450J wont move

    Thank you so much. Cant wait to try this. I have cleared the codes on the TCU before but not the dash monitor. Just ran across instructions in a service or operators manual that told me how to do that. The TCU seems to be completely unresponsive. Just showing those two codes back and forth...
  10. M

    John Deere 450J wont move

    Awesome. How would I get in touch with @mg2361?
  11. M

    John Deere 450J wont move

    We have a small bulldozer, s/n T0450JX139324, that we were using to clear fences with and the operator told me he had a problem. The dozer starts fine, but wont idle up, hence it wont move. Blade works fine. Error codes on dash screen: F423 and F9C3. The TCU also has codes flashing on it...
    • Msh2
    • Thread
    • Replies: 13
    • Forum: Dozers
  12. M

    LRG-425 won’t start

    I have a generator that is powered be an LRG-425i. Build date is 1/10/1999. Carbureted. Runs in propane. It wasn’t starting and we hired a mechanic to service it. Did a tune up - new plugs, wires, oil filter, air filter. Checked the radiator. It was low - the jacketed heater was too hot and...
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