Won’t Shift and ABS Light On
By Ken Freund
October 28, 2016
Filed under RV Tech Q&A
The ABS light on my motorhome flashed as I started to leave home today. As I gained speed to about 5 to 6 mph, a buzzer went off and the transmission would not shift; it remained in first gear. I cannot shift to reverse or neutral. I turned off the engine and restarted it and was able to shift to reverse and neutral again, but the ABS light flashed as a fault indication. Then as I gained speed to 5 to 8 mph, the buzzer started and the transmission again won’t shift. What is the solution? Is there a reset?
Andy Housley | Alice, Texas
There is no “reset” unless you consider a repair a reset. It would be helpful if you included the year, make and model of your motorhome. However, I can provide some generic information. When you start out and begin to drive, the ABS computer “looks for” a signal from the vehicle speed sensors, and if it doesn’t “see” that, it illuminates the warning light and shuts down the ABS. That’s because it requires a reliable signal to operate. This also sets a trouble code in the computer that should indicate exactly where the problem lies, and that can be read by a code reader plugged into the OBDII diagnostic port.
At the same time, the automatic transmission also requires a vehicle-speed signal in order to determine when to shift. Therefore, I believe the two problems are related by a shared common problem: loss of speed signals. Have a shop that’s good with computer diagnostics check it out with a scan tool. It’s very likely that your problem is caused by a sensor failure.
We just bought our first motorhome, which is a 2003 Georgetown 306. It is on the GM Workhorse chassis, and has only 23,000 original miles. I don’t know what engine or transmission it has. How do I determine what I have? Are there any specific maintenance items I should be concerned with?
John Bodine | Brooksville, Florida
The chassis is powered by an 8.1-liter GM Vortec V-8 engine coupled to an Allison automatic transmission. This is a very common powertrain, and most RV shops are very familiar with them. Just as with any gasoline-powered motor vehicle, the engine oil and filter should be changed regularly, and all fluids and lubrication checked. Many people overlook changing the brake fluid and coolant every few years, so I will mention this as a reminder.
Some of the Workhorse chassis had problems with faulty brake calipers that dragged and/or stuck. Also, the GM P-chassis and subsequent Workhorse chassis with the automatic parking brakes had a number of problems and should be checked over by a shop familiar with them. You can search for recalls online at www.nhtsa.gov/recalls.
One of the better sources of information (besides the booklets that came with the motorhome) is www.rv.net. There are discussion threads on all sorts of subjects related to motorhome maintenance and repair. You can also find the various manuals for sale on www.eBay.com, or you can just do an online search for “Workhorse motorhome manual” or something similar.
Fogged Double-Pane Windows
Almost all the double-pane windows in our 2006 Fleetwood Discovery have become foggy on the inside. Is there an easy fix (short of removing and replacing the glass) to clearing the glass in our unit’s sealed windows?
Cathy Devins | Kelowna, British Columbia, Canada
The good news is that the windows can often be repaired. There are a number of shops that perform this work. The bad news is, it typically requires window removal. Internal fogging is caused by a leak in the seal between the panes. Not all fogged windows can be repaired, and some must be replaced. If the windows are fogged white, the glass may be etched, which may require replacement. If only wet, then they can be cleaned and resealed. MotorHome published an article on replacing a fogged window in the June issue (“Motorhome Window Swapping”).