O/D OFF light flashing... again... please read.

[discbrks]

I've read all kinds of posts on this subject. Now that I'm selling my truck, its mad at me and wants to throw a fit. Here's what's happening:

Drive down the road and trans shifts just fine - goes thru all gears including lock-up & o/d. Once I reach 45-50 mph, EITHER one of two things happens. I can't tell which. Either the converter unlocks or it shifts out of o/d. Once this happens, the o/d light starts flashing. It will stay this way for a few miles, whether I'm in stop & go traffic or maintaining a constant speed on the hwy. Within a few miles, the light goes off, trans shifts into o/d (or converter lockes up) and its just fine. It might not act up again for days.

I've been told that once the light is off, the "code" is gone. I've heard that I can pull codes by jumping a wire on the test plug & using a multi-meter. I'm gonna go out in a few & see if there are any codes. If not, I guess I'll just start driving and hope it throws a code. I'm also gonna check the fipl, but I really don't think is the problem. It's been changed twice in the last 5000 miles. My guess is that either the converter is going bad or the solenoid pack needs replacing. Any suggestions? Am I on the right track?

I need to at least find out what the problem is today. I have a guy coming over to see the truck tomorrow and I wanna be able to tell him what's wrong.

 

[DragRag]

An OBD 1 code reader is only about $25 at autozone, worth the money IMO. Get one and read your codes, it's like shooting in the dark if you don't know what code it's throwing.

 

[discbrks]

Got a p/n for the code reader? Don't see anything on their website.

 

[discbrks]

Got a p/n for an Equus 3145 at O'Reilly's. Headed there now. Maybe the truck will act up on they way.

 

[icanfixall]

I had a problem almost exactly like yours... Turned out to be dirty electrical connections to the trans but... I had three differant dealerships throw parts and money at it... They never did fix it... Someone here told me what to do... First off there are around 6 or 7 connections that sometimes get dirty. Three are found under the master cylinder in a bundle and the rest are on both sides and the back of the trans. Clean them with contact cleaner thats harmless to plastic... Let dry... Then grease with some die electric grease... Problem fixed forever. After I spent time... Money and a new trans, tps and computer Ford customer service told me they would help me with the costs... Why you ask..... Those rat ******** told me I should have continued to return to the first dealer for any additional repairs... Make them fix it... Not try to "find" a dealership that might be able to fix it.... I'm so done with any Ford dealership... Four dealerships within 6 miles of my home have gone out of business.... I guess I win....

 

[Russ]

I don;t think the AutoZone scanner will work on these trucks.

 

[G. Mann]

Not sure, but this might help. Had the same problem with my 99 powerstroke. It was the speed sensor in the differential that had failed due to metal flakes shorting across the magnet. This sensor sets on top of diff, little to the side. When the flakes short out, trans loses speed signal and kicks out of OD. Also gives other wacky signals that rely on wheel speed, so you go to fail "get home" mode.

Perhaps worth a try. New sensor is less than $20 at Napa. Perhaps someone here is much more knowlegable than I am if Ford used the same system for a 94....????

 

[discbrks]

Well I drove the truck to Oreilly's to get the scanner. O/d light flashed the whole way. Cranked the truck up to leave the store and no flashing.... So I came home, plugged in the scanner and got a code of 29, which means:

Insufficient input from Vehicle Speed Sensor (VSS)
or...
Insufficient input from programmable speedometer/odometer module.

Now that has me puzzled...
Do we have a VSS? That's not the RABS sensor, is it?

The odometer and speedometer seem to be working fine. Could they be on the fritz and I not know it?

I'm gonna go clear the codes, drive some more, and hopefully the light will start flashing again. I'd feel better if I could check the codes with the light flashing. Any of this sound familiar?

p.s. Thank you guys for the fast responses so far. You guys are awesome!

 

[icanfixall]

Clean the vss senser in the differantial or replace it.....

 

[discbrks]

Going to clean it now....

 

[discbrks]

Pulled it out. The is a bunch of metal filings around the outside of the sensor and a few on the sensor "eye". I think since its $20.00 at advance I'll go get one. I report back in a little bit.

 

[trackspeeder]

Pulled it out. The is a bunch of metal filings around the outside of the sensor and a few on the sensor "eye". I think since its $20.00 at advance I'll go get one. I report back in a little bit.

Metal on the sensor will make it have a fit.

 

[discbrks]

Alright... I cleaned the sensor, cleared the code, and all seemed great. Drove to the store to buy a new sensor & trans shifted fine. Came home & installed sensor. Drove to wash the truck and on the way back it started acting up again as I rounded a corner. OD light flashed for about 1 minute then stopped. When it stopped, the trans shifting thru the gears really fast (I was in o/d at 30mph) and lugging. Got home & pulled the codes... same code 29. Pulled the new sensor hoping to find it dirty... nope. Just oily. What now? You think the sensor got something on it, them it fell back off? I'm gonna go clear the code & drive it to see how it acts.

 

[discbrks]

Just drove it w/ codes cleard and it did fine. What gives? I'm afraid the problem will come back. I don't wanna sell the truck if somebody's gonna have trouble with it 2 days from now. Maybe I should pull the axle cover & clean inside the diff. really good and put it back together?

 

[firemedicmonkey]

sounds like the cheap (<$20) made in China sensor you just bought might be bad... just b/c its new doesn't mean its not defective (esp if made in china!!!) I had it happen with 3 headlight switches in a row from Autozone a while back... If after you cleaned the OEM one it worked fine then I would just return the new one and run with the cleaned oem... also clean any of the connections going to / from it and grease...