2004 V8 O/D Off light flashing

[pet575]

I'm sure this will be a progressive thread as I work though this.

Light flashing and "check transmission" alert started today at highway speed. Tranny won't go into overdrive but otherwise shifts perfectly normally. I get the alert only after traveling at highway speeds for a few miles. If I turn the O/D Off using the switch on the shifter it will still happen. Need to drive it more to verify but I'm pretty sure it shifted into O/D at about 45-50 MPH so that has me a little confused.

I couldn't get a code reader from O'Reilly and Advanced Auto so I couldn't find anything out. I guess my plan at this point is to pay to get the codes read and try to figure it out from there. From what I've seen around the threads here I suspect either a bad solenoid pack or a bad torque converter. I suppose the o-ring servo bore fix for just the overdrive servo is a possibility as well.

Anyone have any other guesses/speculation on this one? Just seems to me like a bad torque converter would be causing me other symptoms.

 

[05XLimited]

What were your RPMs at highway speed? I would lean more towards servo bore, as when my solenoid pack went bad it had erratic shifting that caused it to throw the "Check Transmission" alert. When I was researching, I found that people who had servo bore issues could get the transmission to go into OD when going downhill and it would kick back out when going at any incline or even on flat ground.

 

[imp]

I'm sure this will be a progressive thread as I work though this.

Light flashing and "check transmission" alert started today at highway speed. Tranny won't go into overdrive but otherwise shifts perfectly normally. I get the alert only after traveling at highway speeds for a few miles. If I turn the O/D Off using the switch on the shifter it will still happen. Need to drive it more to verify but I'm pretty sure it shifted into O/D at about 45-50 MPH so that has me a little confused.

I couldn't get a code reader from O'Reilly and Advanced Auto so I couldn't find anything out. I guess my plan at this point is to pay to get the codes read and try to figure it out from there. From what I've seen around the threads here I suspect either a bad solenoid pack or a bad torque converter. I suppose the o-ring servo bore fix for just the o-ring servo is a possibility as well.

Anyone have any other guesses/speculation on this one? Just seems to me like a bad torque converter would be causing me other symptoms.

"Bad torque converter?" Yer barking up the wrong tree! Need codes to confer further. imp

 

[pet575]

Well I drove it again this morning and it does NOT shift into O/D at 40-50MPH. Must have been my imagination or wishful thinking last night. But I still don't get the flashing light or error code until I'm at 60MPH or above. If I'm doing 50-ish, it won't throw the code even though it is not shifting into O/D, either.

At 60MPH on flat ground I'm rolling at about 2200 RPM; at 70MPH it is more like 2600. Increases to 3000 on inclines. When O/D was working it was less than 2000 at 60MPH and maybe 2100 at 70MPH.

One other small detail I left out last night. For many months I've had a very slight delay in shifting/engaging when going from Park to Reverse or from Reverse to Drive. Solenoid was serviced way back at 40000 for similar issue but the symptoms were WAY worse. I'm at 234000+ now.

IMP, I'm comforted to know you think my mention of the torque converter is a little far out there. I'm trying to figure out how/where to get my codes read. I'd really like to avoid the stealership and I don't have a local tranny shop that I trust due to lack of previous transmission problems with any vehicle. O'Reilly and Advanced Auto both said their readers only do Check Engine or ABS lights. I thought I had seen otherwise in a few threads on here. Was hoping I could score a free method to read the codes but I guess that isn't in the cards.

My thought is to take it to the local mechanic I use for my other stuff I can't handle and see if he can at least read the codes and give them to me. I'm willing to pay him for his time to do that for me.

 

[pet575]

While driving today over my lunch break I realized that I forgot to mention that I've also had the little "bump" downshift when coming to a stop. A rough downshift from 2 to 1, I think. Has been going on for probably more than 20K miles.

I contacted my mechanic and I am going to leave it overnight for him to read the codes tomorrow morning. Hopefully he can help me get going in the right direction. I'll update ASAP.

 

[imp]

Pet, be aware that the shift into O/D occurs before the Torque Converter Clutch is made to engage. If at road speed, say over 50, as you say the engine rpms climb higher on slight incline, the clutch is likely not engaging, though the transmission is already in O/D gear.

Under normal driving at say 55 or more, cruising with just enoiugh throttle to stay at speed, if a hill causes downshift, that will always be the clutch unlocking in the torque converter, this is not a true downshift of gears. Then, if the PCM still isn't happy, it will downshift to 4th. gear from O/D (5th.), the converter clutch remaining unlocked.

You can easily check this out by carefully observing your tachometer. Watch it drop as you accelerate under low throttle through the gears, holding throttle steady. First drop, 1st. gear to 2nd; second drop, 2nd to 3rd, third, 3rd to 4th, fourth, 4th. to 5th. (O/D), fifth drop, converter clutch locks. If you don't get all 5 drops in engine speed, something's f...ed up.

The "reveal" on a fail to engage torque converter clutch is at cruise, level ground, not accelerating or slowing down, steady throttle pressure, increase throttle pressure VERY SLIGHTLY, just enough to start raising speed of vehicle higher--- if the tach. jumps higher the clutch has FAILED to be engaged.

I'm suspecting this is your problem. The code(s) could be P0741 (TCC SYSTEM IMPROPER MECHANICAL PERFORMANCE); P1742 (TCC CLUTCH SOLENOID FAULTY); P1744 (TCC CLUTCH SYSTEM STUCK IN OFF POSITION.

Please let us know about your codes! We can all learn a little more about these electronic marvels! imp

Edit: Your transmission is a 5R55-S

 

[pet575]

Well, I'm not sure what I think about today's events. I took the vehicle to my regular mechanic last night and instructed them to ONLY read the codes and report back to me what they were and that I would gladly pay them for their time to do so. Their response was that they "thought they could do it" and to drop it off so they could "try."

They called today to advise me that the codes were related to the torque converter "sticking" and that they put two tubes of Shudder Fixx in it and it smoothed it out right away. Since it worked, they cleared the codes and are sending it on its way. When I asked for the specific codes they could not tell me because they had been cleared.

I'm wary of this but I guess I have no choice at this point. I suspect I'll be posting a follow-up message on here before too long but maybe I'll get lucky. If that is the case it will be going to a transmission shop for code reading.

Hopefully I won't have any further update for this thread, but I'm not holding my breath. Not very happy that I have no codes but I'm not completely unhappy based on the small percentage chance that this actually works.

 

[pet575]

My suspicion is that they were unable to read the codes/didn't read them and their answer to what they diagnosed to be a sticky TC was to put this product in it.

 

[05XLimited]

My hope would be that they didn't put that into your transmission and it wreaks havoc inside requiring a full rebuild. The codes would have given better insight into what was going on.

 

[pet575]

Well I drove it home last night and parked it and then tested it out this morning. Same symptoms. However, it appears that this magic tonic has smoothed out the bump/hard downshift so it at least benefitted that. Today I'm going to work on figuring out a real transmission shop that I can get this thing to in order to get codes read and put into my hands.

IMP, I am getting every drop from 1-5 I just never get that last drop which, as you say, appears to be the TC lock. If I understand your post correctly then if the codes you expect to be given are truly the ones, then OD servo is not functioning correctly?

05XLimited, agreed. Hopefully I can get this taken care of before too long so I can drain that stuff out of there ASAP.

 

[pet575]

Going to take the vehicle to a real transmission shop this afternoon to get the codes read for $35. Will report back.

 

[pet575]

Codes are B2103, P1000, and P1744. Doesn't seem like the first two are all that relevant to a transmission problem.

 

[imp]

Codes are B2103, P1000, and P1744. Doesn't seem like the first two are all that relevant to a transmission problem.

My list shows no "B" codes. P1000: Mass Air Flow Sensor Intermittent

P1744: Torque Converter Clutch System Stuck in Off Position.

Mass Air has nothing to do with torque converter, but will affect drivability and performance. Your test drive seems to confirm the TCC is not engaging. If you like, you can drive the truck safely with no harm to the transmission with the TCC unlocked, forever if you don't mind losing a couple % of your fuel economy. The engine will simply turn faster when more power is demanded.

Ford used the flashing O/D Off light as a convenient warning; it has in your case nothing to do with 5th. gear. Replacing the Mass Air Sensor may likely get the truckl running good again. imp

 

[05XLimited]

The list that I have with codes lists B2103 as a "body" code. States that there is an antenna that is not connected for the PATS system.

 

[pet575]

My list shows no "B" codes. P1000: Mass Air Flow Sensor Intermittent

P1744: Torque Converter Clutch System Stuck in Off Position.

Mass Air has nothing to do with torque converter, but will affect drivability and performance. Your test drive seems to confirm the TCC is not engaging. If you like, you can drive the truck safely with no harm to the transmission with the TCC unlocked, forever if you don't mind losing a couple % of your fuel economy. The engine will simply turn faster when more power is demanded.

Ford used the flashing O/D Off light as a convenient warning; it has in your case nothing to do with 5th. gear. Replacing the Mass Air Sensor may likely get the truckl running good again. imp

So if I'm looking to get the tranny back to full functionality what is the best plan? Not surprisingly, tranny shop said it required a rebuild.

 

[imp]

The list that I have with codes lists B2103 as a "body" code. States that there is an antenna that is not connected for the PATS system.

Thank you for that! imp

 

[imp]

So if I'm looking to get the tranny back to full functionality what is the best plan? Not surprisingly, tranny shop said it required a rebuild.

Your original post states the transmission shifts perfectly normally, other than (you thought) going into overdrive. We seem to have determined the real issue is in the torque converter, or the devices which control it's lockout clutch.

The trick now is to find out why the clutch is not engaging, or, as I said before, just drive it without the clutch operating. Rebuilding the transmission will only add cost to the deal, but replacing the parts screwing up the clutch function are an option you must decide on. There's too much not known, for me to tell you what I would do. How many miles on transmission, will you plan to keep the truck a long time, etc.

What I would do is test the TCC solenoid for coil resistance and short to ground. This can be done without touching the transmission at all. If OK, then drop oil pan, remove solenoid pack, looking for bronze metal shavings, their plunger guides disintegrate, if OK, in all likelihood the trouble is in the converter itself; at that point, I would replace it. Gotta yank transmission out to do that. High miles? Then logical to rebuild while it's out. Definitely, then, replace the solenoid module as part of the rebuild.

If you opt to buy a remanufactured transmission from Ford (best way, IMO), you will get a rebuilt torque converter as part of the deal. And 3 years/36,000 mile warranty. Nobody else I know matches that warranty. imp

 

[pet575]

Thanks IMP. The transmission is stock and has 234000+ miles on it. Solenoid pack was replaced at about 45000 under warranty but no other work has been done on it. Ideally I'd like to keep this vehicle for another year or more . I don't have the funds right now for a car payment so I'm willing to spend some money if necessary. But I'd REALLY like to DIY this if possible. If I have to do a rebuild the shop I took it to said they'd do a complete rebuild of the tranny and torque converter, replacing every part and not just the ones that "look bad"for $1800-2000 with a 1 year/12k mile warranty. I didn't think that was all that bad of a price compared to some of the prices I've seen around. U

So is there a link for the test I can do to get me heading toward figuring out I'd this is the solenoid?

 

[pet575]

Also, I've noticed since this issue arose that I don't seem to have as much power at idle. Seems to take a bit more throttle to roll the truck from a stop. Also noticed that now the ruck can/will roll backward a little at idle on an uphill incline. However, the engine codes I got relating to the IAC and the MAF could be causing that. Any possibility that the TC error alone could be causing this problem? Or is the engine not idling properly the real place I should be looking?

 

[05XLimited]

I know using an OBD II scanner with live logging can check for short or resistance issues. When I was having troubles between 2 and 3, using a "eBay special" scanner and software I was able to detect the solenoid issue.