How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Pete Your Own Question
Pete, Technician
Category: Car
Satisfied Customers: 23859
Experience:  17 years automotive training and experience.
Type Your Car Question Here...
Pete is online now
A new question is answered every 9 seconds

GM National RV Dolphin: I have a 2005 National RV Dolphin with

This answer was rated:

I have a 2005 National RV Dolphin with a Workhorse Chassis. 8.1 Vortec engine and Allison Transmission. On several occasions it has suddenly shut down to a safe mode and given a check engine code of U0107, meaning lost communication with throttle control actuator. After resetting to check engine light, everything works a normal. This only seems to happen about every 1,000 to 2,000 miles and the last 3 times occurred while I was setting the cruise control. I have had it in to the Workhorse shop numerous times for this problem and they have had no luck identifying and fixing the problem. Where do I go from here?
My name is XXXXX XXXXX I am a professional here at Just Answer. I noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

The loss communication with the throttle actuator can be a common fault.In most cases this is an intermittent fault with the throttle actuator itself (usually part of the throttle body itself) and had to be replaced to correct this here.

I would have the throttle actuator wiring checked to make sure there is no wiring damage as well as the electrical connection is tight at the actuator.You might try and wiggle the wiring harness at the throttle actuator and leading off of it to see if the vehicle acts up when this is done.If it does act up this indicates a fault in the wiring and the wiring needs checked further to locate a short in it and then repaired.

If no faults are found with the wiring and with the common fault I have seen before in some cases this sounds to be an internal electrical fault in the throttle actuator itself.This can be very difficult to identify as the fault with the intermittent issue like this,I have ran into this several times before.

Let me know if you need anything else,thanks Pete.
Customer: replied 3 years ago.

The wiring has been checked several times. Everything on you list has been checked except the throttle body has not been replaced. The unusual link here is the cruise control. Why does it only seem to be activated when the cruise control is being set? There is another issue with the dash cluster where on very rare occasions when I go over a very noticeable bump the dash cluster will shut down momentarily and then restart, but, the engine does not stall and no check engine lights come on. I had the dash cluster replaced about 2 years ago. It did this before the dash cluster was replaced as well.


This may still be a fault with the throttle body itself as I have seen these fail and the cruise is tied into the electronic throttle body and if the computer is trying to activate the cruise and sees a fault when activating it will cause this or if the throttle body has some degree of voltage differences in it or communication issues when the cruise is being set this will cause this as well.

As for the cluster issues if this occurs going over bumps this sounds like a loose connection either at the cluster itself or one of the voltage or ground signals to the cluster are at fault causing this.Unfortunately my info doesn't list a diagram on this vehicle to tell you what grounds or voltages to check but this does sound like a loose connection.This loose connection may also be involved with the throttle issue.

Thanks Pete
Pete, Technician
Category: Car
Satisfied Customers: 23859
Experience: 17 years automotive training and experience.
Pete and other Car Specialists are ready to help you

I am following up with you to see if you still needed help with your question you had asked.If my help didn't satisfy your question please let me know so we can continue.

Thanks Pete

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
< Previous | Next >
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles Walnut Creek, CA
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue Charleston, WV
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, do indeed know your stuff. Jim Castleberry, FL
  • Excellent reply, and also very quick. Really sounds like the Expert knows what he is talking about. I will be back to use your service when I need more help with my RV. Dutch USA

Meet The Experts:

  • Chris (aka-Moose)

    Chris (aka-Moose)


    Satisfied Customers:

    16 years of experience
< Last | Next >
  • Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)


    Satisfied Customers:

    16 years of experience
  • Ted G.'s Avatar

    Ted G.

    ASE Certified Technician

    Satisfied Customers:

    20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
  • George H.'s Avatar

    George H.

    ASE Certified Technician

    Satisfied Customers:

    ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist
  • GM Tech (Cam)'s Avatar

    GM Tech (Cam)

    Auto Service Tech

    Satisfied Customers:

    GM Grand Master Technician 2007. 14 years experience.
  • Amedee's Avatar


    Former ASE Master Tech

    Satisfied Customers:

    ASE certified tech advanced level specialist. Wisconsin certified emissions state inspector
  • Jerry's Avatar


    Master Mechanic

    Satisfied Customers:

    ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager
  • Richard's Avatar


    ASE Certified Technician

    Satisfied Customers:

    12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes