Flashing OD light, no power

[Gander12]

Thought at first that there was an engine problem, but the symptoms point to the tranny:
The transmission seems to occasionally "disconnect," engine drops to idle, "check engine" light comes on and the truck coasts with no power going to the wheels. Initially it was just doing that for a few seconds, then back to normal.
This AM the problem was accompanied by a flashing OD light and very hard shifting, lasts maybe 10-20 seconds then back to normal.
Fluid level is ok, nothing burning.
Stock 1997 automatic 3-spd with OD in a stock 97 2wd F250.

[RadarRider]

Originally Posted by Gander12

Thought at first that there was an engine problem, but the symptoms point to the tranny:
The transmission seems to occasionally "disconnect," engine drops to idle, "check engine" light comes on and the truck coasts with no power going to the wheels. Initially it was just doing that for a few seconds, then back to normal.
This AM the problem was accompanied by a flashing OD light and very hard shifting, lasts maybe 10-20 seconds then back to normal.
Fluid level is ok, nothing burning.
Stock 1997 automatic 3-spd with OD in a stock 97 2wd F250.

Start with the basics: see what you get for codes. That'll @ least give you your general area(s) to look. But just out of curiosity, how are your batt. connections & batts. themselves? Recently, I had similar symptoms with my rig coasting like it was 'disconnected', with the OD light flashing & poor shift performance. The only difference I had is after experiencing this, I had stopped @ a gas station for fuel. When I went to start my truck again, it was like the batteries were dead. I waited a second & tried again & it started. All the way home I still had the OD light flashing with crappy shifting. The next morning before work, I tried starting it & it buzzed again like it died @ the gas station. I tapped the terminals with a rubber mallet & the truck started. When I went to work that morning the OD light was flashing, but went out about 1/4 way to work. The truck didn't start when I tried leaving work....again. I tried the mallet trick but it didn't work. I replaced the batts. & the truck fired right up & I never had the OD/tranny crap problem again. Although, before you go buy new batts..........................scan your rig for codes!

[bigcountrysg]

Your going to have to have a trans shop pull the codes. When the OD light is flashing that is like the check engine light. How ever a normal code reader or scanner usually can not pull transmission trouble codes.

It sounds like an electrical communication problem from the transmission to the pcm. I would stop driving the truck and have a transmission shop take a look at it.

When the od light flashes then the truck goes into limp mode. Which means you get hard shifts and the truck is still driveable. How ever I would not drive it like that for a long distance. As right now it could be a shift soleniod. But if you do not have the problem resolved you could damage the transmission and cause yourself to have it rebuilt.

[Phiber Optik]

The newer snap-on dianostics can pull tranny codes, most reputable shops should have one

[03f250stroke]

when lights flash, tow haul, OD, its never good.

my truck doesnt show the what gear i am in P,R,N,D anything. i have had tow haul flash before. different trans then you but i would start off doing what these other guys said. makes sense to start somewhee

[OregonStroker]

ya take er to a shop. they will tell you what it is for sure.

[SteveKran]

I had this crap happening to my tranny about 4 months ago....ended up needed a rebuild. The solenoid packs were bad in the tranny

[Phiber Optik]

I had a similar problem, after reading the codes a trans shop said they were 90% sure it was the solenoids, So I just ended up dropping the pan and replacing the soleniod packs for $250 and now it's fixed

you need a 10mm deep socket and a T-30 torx bit

[Gander12]

The only codes were CPS and TPS; CPS was replaced earlier under a recall, turns out the replaced part was also duff so I had that replaced again for free, but didn't cure the problem, or in fact change the symptoms at all. No one sells just the accelerator pedal position sensor, have to buy the entire assembly for which the dealer wants $600 Cdn. Best I've found in a wrecking yard was $250 Cdn.
The sensor is a sealed unit, tried cleaning the spring as best I could with contact cleaner. Does anyone know of a way to test the unit? It might well be the input side of the PCM rather than the output side of the accelerator sensor, hate to buy a new part I don't need but can't think of any other option to see if it works.
Conversely, does anyone out there have a sensor from a wreck they want to dispose of?

There are no other visual indications aside from "check engine" and the flashing OD light; but mine isn't a digital dashboard. I'm not driving it until I figure it out, so no worries about thrashing it any worse. I have found that when it acts up, it goes away if I accelerate hard to about 3000 rpm.
The hard starting problem still exists even with the new CPS, would that point more to the accelerator sensor rather than a tranny problem? It still pukes out huge amounts of white smoke while cranking, just like if I was down on the pedal while trying to start.