Lazy Daze Owners' Group

Flashing transmission control indicator warning light

October 03, 2020, 10:10:59 am

Hi Group,

We had a new problem crop up with our 2003 LD and thought it might be helpful to share what happened and the outcome.
Some background info;. Our 2003 Midbath has around 137,000 miles on it and we are the original owners and we don't tow a vehicle behind us. I have had the transmission fluid flushed around every 25,000 miles, but had never had the pan dropped or filter changed.

Mostly due to Covid concerns we have not traveled this year; our rig has been parked at home but I had driven it around 10 miles on a couple occasions. Last week I was taking it for another 10 mile drive after clearing out a fresh rodent nest around the under hood fuse box. As I was driving down my street the "Service engine soon" warning light came on and stayed lit (not blinking) but the rig was driving fine; a steadily illuminated light usually indicates an emissions problem and is not urgent. Just as I was pulling back on to my street, the "Overdrive Off" light on the transmission stalk started blinking. The 2003 Ford owner's manual doesn't say much about this other than "have the system serviced immediately".  I said bad words....

I could not find much information about that warning light on this site or by doing online searches. Most of what I did read was that this might be something really bad and it often meant it would be time for a new transmission. Grrrr..... I drove out to see if the service facility I had been using was still working on RVs and spoke with the service manager. He said I should bring it in to let them read the trouble codes; he doubted it it needed a transmission. I was concerned about even driving it the 12 miles to the service center. During the drive there, the transmission light went off but the "service engine" light did remain on and the rig drove perfectly. As I backed it into a parking spot the transmission light started blinking again.

Their diagnostic equipment came up with two trouble codes; # P0705 and # P1702.  I was told it needed a new "transmission range sensor". This sensor apparently links the engine/computer and the transmission.

While it was there, I asked them to check parking brake fluid  (I had that unit rebuilt many years ago) and to have the transmission pan dropped so they could change the filter and evaluate the fluid and any metal that might be apparent. I was told the fluid was in excellent condition and the filter and the magnet on the transmission pan were very clean too. And my transmission parking brake was also in excellent condition!

I hope this info was interesting and helpful to some of you.

Steve K

Re: Flashing transmission control indicator warning light

Reply #2 – October 03, 2020, 12:52:03 pm

It might be worth adding that a flashing OD light on the transmission shift lever can mean various things. It is important to get the actual trouble codes read as soon as possible, consult with a transmission specialist and then proceed from there. In our case it meant a failing torque converter and a rebuilt transmission.

We were of course on a trip, near Victorville, CA, over four hundred uphill miles north to home, on Friday of Memorial Day weekend. We got in touch with John Wood Transmissions in Holtville, CA, two hundred downhill miles to the south, decided to go there instead of home, and he was able to rebuild our transmission over the next week or so. Great guy, superior work.

I'd also underscore that the flashing overdrive light can be intermittent. In our case it came and went frequently as we made our way around Victorville getting the codes read, finding a place to stay over the weekend and then on our way to Holtville. I'd say if you get a flashing OD light it is time to get to available help with figuring out and repairing what's wrong. Don't let the light going out tempt you farther into the wilderness.

Re: Flashing transmission control indicator warning light

Reply #4 – October 03, 2020, 01:46:55 pm

According to their website, John Wood Transmissions is not longer doing transmission rebuilds in-house. The business changes are detailed here:

John Wood Automotive -  

Re: Flashing transmission control indicator warning light

Reply #6 – October 04, 2020, 12:11:39 am

When John Wood rebuilt our LD's transmission, three years ago, the receipt was from mechanic whose shop occupied part of the building where John's shop was located.
There is a good chance there is a local shop in the scenic Holtville area or nearby, who will buy and installed a remanufactured unit from John.
In the winter, the southern desert is loaded with snowbirds, many own diesel pickups with boosted engines, John's specially is building transmission that will stand up to large increases in power, our wimpy V10s or even the new V8s have much less torque and horsepower, which should lead to a long life.
At the time of our transmission's replacement, he was building a new shop, fully air-conditioned and designed specifically for transmission work, somewhere outside of town.

Larry