Random Fuel Gauge Problem

[RamblinFever]

On at least four occassions I have been startled by a beeping sound and a message stating that I am out of fuel - can't remember exact wording of the message. The fuel gauge drops to empty but almost immediately the beeping stops and the gauge returns to the proper indication. Has anyone else experienced this problem?

[RamblinFever]

On at least four occassions I have been startled by a beeping sound and a message stating that I am out of fuel - can't remember exact wording of the message. The fuel gauge drops to empty but almost immediately the beeping stops and the gauge returns to the proper indication. Has anyone else experienced this problem?

[M&EM]

Probably most of us have seen this occurence. No known fix that I have heard about. Happens at least once on any day long travel I have ever made. Lets me know co pilot is paying attention and awake since she always hears the beeping sound then asks me to check fuel gage.

[Joe Gilbert]

Perhaps DriVer can add something but my understanding is that the gauges and other electrical sensors all report to the ECM via a bussed electrical interface. If for any reason the computer does not see an input from the fuel gauge the gauge will respond as you described. This may be a software issue and not a faulty gauge at all. I have very occasionally seen all of my gauges drop to zero, than immediately return to their normal values.

Two wire bussed systems are the rule not the exception on modern automotive systems. It appears Workhorse does not, or did not in 1993/4, have all of the bugs out of their system.

[ghamblen]

I have had the same problem. Seems to effect the fuel guage only. Happens once every one to two thousands miles for me. I have had the IP replaced twice for various reasons and this problem still exists. I think Joe Gilbert is right on. Spurious signals or lack there of is probably the culprit.

[RamblinFever]

Thanks for the info. I had the IP replaced last summer an thought it might be a more seriousl problem.

[Horsepowerfan]

This has also happened on my coach a few times. Based on my experience working on GM vehicles with this same condition and reviewing the information in the WCC Service Information manual, I have arrived at this theory:

The fuel level sensor card may have deposits on it from sulfur in the fuel. As the fuel sloshes around, the float arm moves up and down and the contacts on the arm move against the sensor card. If at any time there is not good contact between the float arm and the sensor card, then no signal will be transmitted to the engine computer. This results in the fuel gauge dropping to empty, causing the instrument panel to respond audibly and to display a LOW FUEL LEVEL warning in the Message Center. Once contact is re-established, everything goes back to normal.

Here's an excerpt from a technical publication available to GM Service Professionals. While I haven't felt the need to use this product in my motorhome due to the infrequency of this condition occurring, I may start using it as a preventive measure. I am not by any means trying to promote the use of this product, but wanted to let everyone know that it is available and it may help.

<span class="ev_code_RED">(I would recommend checking with either Workhorse or your coach manufacturer before using any type of fuel additive.)</span>

<span class="ev_code_BLUE">GM Fuel System Treatment PLUS (p/n 88861011; in Canada 88861012)

The PLUS portion of GM Fuel System Treatment is the addition of a "filmer"� additive that, when used regularly, can protect fuel sending units from the corrosive effects of sulfur contaminants found in some of today's gasoline.

Sulfur contamination may disrupt electrical continuity of fuel sending units and lead to erratic or false fuel gauge readings. When used regularly, GM Fuel System Treatment PLUS provides protection against the effects of harmful sulfurs in gasoline.

One bottle of GM Fuel System Treatment PLUS added to the fuel tank at each oil change:

Cleans: sulfur corrosion from fuel gauge sending units.

Prevents: harmful sulfur components from attacking sensitive fuel system electronics.

Protects: by coating metallic surfaces of the fuel system.

Removes: engine deposits left from use of poor quality fuels.</span>

Depending on the severity of the buildup, it can take quite a few treatments. Taking into consideration that our motorhomes have much larger fuel tanks and are not driven as regularly as our automobiles, it could take even longer for the treatment to work than for a smaller vehicle (and I am guessing you would have to use more than one bottle per tankful). In the instance where the buildup is beyond cleaning with the additive, installation of a new fuel level sensor may be the only fix.

["007"]

You soundright on with that explaination, JIM, I wonder if the new gas formulas in some areas will cause these people to have more problems. It seems around here I haven't had the problem as much as when we travel to other areas of the country.
Thanks for the info I'm not going to worry about it.