2003 LS V8 Transmission problems or PCM?

Y

yabadaba

LVC Member
Joined
May 23, 2016
Messages
30
Reaction score
0
Location
NY
Hello!
My LS with 122XXXmiles has now developed transmission problems....About a month ago, I changed all the coils and plugs and the car drove like a dream! Then the very same day after some aggressive driving that I haven't done in years, all of a sudden the trans started to shift very hard from 2-3 (could changing the coils and plugs affected the trans some how???). Now it also shutters between 3-4 and bangs back into 1st from 5th. It shifts fine from park to reverse or drive and vice versa. Ive read as much as I can and some people say its an electronic issue, not a trans issues. Or its a solenoid or a valve body. Full disclaimer, I have never worked on a transmission and know only a little from what i researched online.
I went to one trans shop and they said a rebuild would be $2200 but is a rebuild necessary? Can I have the transmission scanned for codes? There are no codes, at least not yet when I hook up my poor man's OBD scanner.
I can't afford to rebuild, but what is the next step to help diagnose what the real issue is? Or does a rebuild basically cover all the next steps in one? The only thing that has been done, is some Mercon V was added and i disconnected the battery to see if it 'reset's the PCM if it is infact an electronic issue.
Thanks for your help!
Y
 
It's a myth that the battery disconnect will do any long term good at all. Your symptoms could be due to a valve body problem, a solenoid assembly problem, or a PCM issue. It's very unlikely that a full transmission rebuild is called for, but if you continue to drive it in this condition, it may get to that point. Why was fluid added? Do you have a leak? Was the level properly checked before and after adding?
You can take the PCM out and send it for repair. This is probably the cheapest (if not most likely) thing to try first. If not that, find a good local hole-in-the-wall transmission place to change out the fluid, solenoids, and rebuild the valve body with a shift-kit. I would guess this would be somewhere between $500 and $1000 total.
 
The first shop i took it to, told me I had a "bad seal" and I guess a slow leak. If I take the PCM out, who do I send it to? Is it worth buying one online? So, you are saying the PCM is probably the culprit?
Is removing the PCM an easy job? I have all the LS manuals too.
Thanks for your response!
 
Dewd, dont give up hope yet. Joe knows his stuff, and having said that it has to be tough to get close to accurate what to do without codes. What I will tell you is your problems sound ALOT like mine (search my posts for more info) and you have 2 issues I see:

- Like me, you have to find a tranny shop that can be trusted. Most go right to the whole thing is shot and you need a full rebuild. That actually translates into we dont want to do the real work we just want to make a quick 2500 bucks or more for doing nothing.
- With no codes, and the fact I doubt your car ever had any tranny service since Lincoln states its a sealed system and no need, the only way to know is do a Fluid service and drop the pan. This I learned from joe btw, and glad I did.

I feel that going at the PCM is the last thing you should do Joe Did mention that for me too. Once I found the right guy - btw Burbank CA let me know if that can help - he rebuilt the valve body. He also replaced the solenoid which he didnt think was bad but we were in there so knowing them since its no more labor do it. $960 bucks at CA prices. Doing this is required for any rebuild anyway, so there is no lost funds. It actually took about 500 miles for the tranny to smooth out after this, but now I am REAL happy with it. Since the guy stated my fluid was bright red, and only a small amount of metal on the collector magnet, I know I can go another 100k. He also at first inspection found no issue with the valve body, but when he went to replace the springs they 'crumbled in his fingers'. Thats why I think I had no codes, it wasnt broke, but it was damn near.

Hope this helps, my 2 cent. Oh, the guy I went too also said I should change the fluid every 40k. I know that relative to the driving style, but I plan to do, just to be safe on the older unit.
 
No, I am not saying that it is probably the PCM. Actually, I think that it is a little more likely to be the valve body. However, the PCM is the lowest cost thing to try first. It's $90 plus shipping if it's not the PCM, or $170 if it is. There are tests that can be done with the PCM on the car to determine if it is the PCM. Unfortunately, few places even know about the tests, let alone how to do them. If they do, it is unlikely that it would cost you less than $90. Here's where to send it:
http://siaelec.com/product/lincoln-ls-ecm-ecu-repair-return/
Here's how to remove it:
http://deneau.info/ls/s6x~us~en~file=s6x3e006.htm~gen~ref.htm

There are three problems with buying a new PCM. 1 - I don't think they exist anymore. 2 - They were pretty expensive when they did. 3 - You'll need a dealer to program it and marry it to your PATS and keys before the car will start.
 
I used to live in CA, not far from Burbank, but now in NY...Thanks for your 2 cents....so really, biting the bullet, would be to go to the trans shop and have them drop the pan to investigate? I just feel like once I do that, I am at their mercy, unless i just tell them exactly what to do (rebuild valve body ) should I let them tell me I need a new solenoid before replacing or just have them do that too?
So I there are two shops by me, one is a AAA rated place seems like a nice guy - they do it all. The second is a straight transmission shop.
 
Whatever you do, don't go to one of those chain shops...
I think that I would replace the solenoids if I had the transmission open and was replacing the fluid and working on the valve body. There's no extra labor for that and the $300 part charge is not that much of the overall bill. After 122K miles, it seems like the right thing to do.
Reviews from other customers mean a lot more than the ratings.
 
Heres another way to look at it, Walt's Transmissions in Burbank (owner) described potential things that it could be known with this model tranny. He basically said that those are things that dont require a rebuild but, he said in all honesty, with no codes, its not likely electrical but he cant be sure unless he 'drops the pan'. So yea we get it, you kind of are at the mercy of the shop. I also knew from our conversation, his reviews on web and better business were tops so I had found the right guy. He even called once he dropped the pan, and said he didnt find any broken springs so he didnt know for sure. I still kinda knew it was too old, and told him to go ahead and do all. Proved to be the right thing to do.

Dropping the pan will also do a couple things. If the fluid is dark brownish red im told somethings burnt inside, also if there is junk (the bands falling apart) in the bottom or lots of metal, then that is bad. That means a total rebuild. So any decent tranny shop will not charge you for that work if you go for the rebuild or a replace.
 
The link joegr provided for SIA is the place I used for my PCM repair. I went the other way ($$>$) because I found out later about SIA and the possible PCM issue. I had 2-3 coils go bad on me over the years so I guess that probably affected the PCM at some point.

I first did a fluid flush (needed to be done anyway as part of regular maintenance), then did the solenoid replacement (when the flush didn't help), then found out about SIA/PCM repair after both a transmission shop and dealership advised I needed a transmission rebuild. The PCM repair was way cheaper than the rebuild of course and it worked! ($200 with shipping to Canada and took about 10 days)

It takes a while to get the PCM out of the car but it's not rocket science. The deneau link also posted is what I followed.

It probably means the solenoid that was removed was fine - so if anyone wants a used solenoid for free (you pay shipping) it's available.
 
I replaced all my coils and plugs right before I started having the transmission issue - Could this have cause the PCM to go bad? I have had a bunch of coils replaced since I have had the car (9 yrs now).
Just shifting while stationary - there is no issue. I can also drive the car just in 3rd and it drives fine. So it seems you suggest I go the PCM route first THEN see what happens?
 
What we are saying is that it is either location. With no codes to give a clue, take a shot at it. I am a fan of rebuild the internal controls of the tranny because it worked for me. I may have to do the PCM in the future, but right now nothing indicates that. I do believe that these transmissions need maintenance way more often than suggested/indicated by Lincoln, so if yours is like most and never been serviced, going there will likely not be a waste.

And again be wary of tranny shops that want to go right to a full rebuild. They should have no problem working on the control systems first, that can be done while the tranny is in the car, and is separate part of a full rebuild. Once they start this work, they would also have clues if the internal systems are bad.
 
As mentioned above it could be either. In my case, I first changed the trans fluid which was due anyway (I do every couple years) to see if that helped - it did not. Then did the solenoid (most expensive of the 3 things I did since I paid a shop to do it plus the price of a new part) but still had the issue. The PCM was pretty much plug and play once it came back from SIA and that fixed the issue - it's been a year now and the transmission still works as it's supposed to.

My symptoms were a hesitation then hard shift up between 60-70 km/h and it would jerk into gear from P>R.

My guess is the bad coils in the past sent bad signals to the PCM and messed it up (I had no codes to indicate the issue; I did have codes in the past when the coils went bad). In your case, if you had no trans issues before you changed the coils then had an issue afterwards then maybe they're related (or could be coincidence). Of course you mention "very aggressive driving" so I'm not sure what that means - if the trans had weakness/issues before then this could have put it over the edge but that would depend on a few things - I don't think these trans are that weak. I've stepped hard on mine several times over the years and I don't think it hurt it or caused the issues I had. How often do you change your trans fluid/filter (I don't remember the setup on this trans).

Also, did you use new Ford coils?
 
I used coils with the same specs, i didn't use motorcraft but i used the right plugs. I forgot to mention that i did have the transmission fluid changed at 100k. I had to go back to them because they put too much fluid and it was leaking, but I had no issues up until recently (122k) with shifting. I wasn't flooring it or anything like that, I was just having fun with it but not stressing the trans/engine too much. It was literally at the end of my drive at low speed that the car started shifting hard between 2-3. I almost feel it is an electrically issues because the shifts may be harder/softer based on how fast I am going.
How long did it take you guys to take out the PCM? Any quirks I should know about?
 
yabadaba said:
I used coils with the same specs, i didn't use motorcraft but i used the right plugs. I forgot to mention that i did have the transmission fluid changed at 100k. I had to go back to them because they put too much fluid and it was leaking, but I had no issues up until recently (122k) with shifting. I wasn't flooring it or anything like that, I was just having fun with it but not stressing the trans/engine too much. It was literally at the end of my drive at low speed that the car started shifting hard between 2-3. I almost feel it is an electrically issues because the shifts may be harder/softer based on how fast I am going.
How long did it take you guys to take out the PCM? Any quirks I should know about?
Click to expand...

Is the fluid level high enough now after the drained some out? Motorcraft fluid?

I don't recall how long it took me but I'm not a tech or super-handy this way - I work on more basic/average items on my car so this was a bit more involved for me. What took most of the time was trying to access some of the hard to reach bolts and screws (like behind the glove box - this part probably took the longest including detaching the cable holding the door to lower it you you could get the unit out). There is a bolt that holds each of the cables that are plugged into the PCM in the engine bay so you can't just depress a clip and unplug them. The engine bay disassembly wasn't to bad...the deneau link has most of the major items but some of the small details I had to figure out myself or ask questions here.

http://www.lincolnvscadillac.com/fo...-LS-any-tips-for-releasing-the-glove-box-door

Do a search - there may have been a couple threads about PCM removal
 
I am not a pro either, but the things that make me still lean to the controls inside tranny is the 'shudders' from 3 to 4. Anyone correct me if I am wrong, but the PCM would be saying 'do this' and if it is not getting the 'do this' it would still be saying it until it got it. The other side would be if the PCM is not saying it when it should, would be stuck in a gear. I have seen other posts describing that. BTW my valve body problem I lost fifth gear at the end, it would not go out of 4th for example.

Also, the solenoid down in the pan is the other side of the electrical. What I know about those is they are electro magnets, and if they are failing, they may go into a fluctuate mode not fully on or off for a bit.

Sorry if this seems confusing, but just trying to throw out possible thoughts. At one point you will have to attack one or the other. Fortunately right at the end of mine before getting in the shop, mine started throwing the no 5th codes, so that told me in the pan.
 
Oh you know what? Not to throw another issue in the mix, but I saw this with my research, and it just kicked back up in my old man brain. With your odd behaviors, I wonder if this is possible in the Lincoln?

https://www.youtube.com/watch?v=DgLBpkTjGZM

Talks about a weak throttle body. Definitely get some experienced input about that though, from like joe or someone, before stressing it may be a third thing.
 
Thanks for the video. I don't think its the throttle body because it shifts great from 1st 2nd and engine is running good, but you never know. I still haven't had time to take out the PCM, but i think that will be my first step, but what about the issues with reprogramming the key and any other electrical issues that might happen ? I was able to program a new flip key on my own, is it the same process?
 
No, it's not the same process at all. If you are planning to replace your PCM with another PCM, you will need a tool that can put the PCM and PATS into secure mode. Then there is a ten minute delay, then you have to follow a different key programming procedure (must have at least two unique keys).

If you are planning to take out your PCM, send it in for repair, and then reinstall your repaired PCM, then there will be no key reprogramming needed. (Your PATS and keys will still be programmed into your repaired PCM.)
 
UPDATE - Took out the PCM over the weekend - hardest part was undoing the screws in the glove box for the bracket holding the PCM. SIA now has an ebay page and the accept offers ; I paid $130 and mailed it today. I'm praying that this fixes most, if not all of the trans issues. Will keep you all posted. Thanks again.
 
I got back my rebuilt PCM after only about 8 days between sending it out and getting it back. I had several microchips that were shorted and the Solenoid circuit was shorted. I put back in (after some wrestling with it) and.....drum-roll........ all the transmission shifting problems are GONE! I thanked every God under the sun! and thank you all! I'm a proud LS owner again!
 
Thank you for the update, and I'm glad it worked for you.
 
Hehe time for atlantic city trip, the dice are in your favor. I sometimes wonder about my PCM too, since even I get a some weird revs before shifts around town (2 to 3 to 4 probably). Of course, I am still probably on first rev of programming, and 5 original coils dont help.

Curious, of course my car's history is mild weather in mid california band, and garage kept to boot, so obviously easy on the electronics. Your car's history? NY would be serious cold, but wonder if you know anymore about where it was. What your repair job was is exactly what was described possible to me when I was trying to decipher my problems, multiple microchips with errors. I may have to budget in this repair as a matter of course.
 
Hey grizzly - so my car is originally a CA car- Ive been in NY about 7 years. Even before I had the bad shifts, the transmission would sometimes jerk into D5 or R from Park. Now, everything is smooth...I guess what happened is when I changed all my Coils and plugs at the same time - the PCM must have not been able to take it. I wonder if my coils will actually last longer due to the rebuilt PCM, but I did find a little oil in some of the CoilPacks - but thats another story. The job is worth the $130 dollars that I paid, plus a few hours and cuts, curse words later...
 
Ya thats what I am wondering, I am doing all 8 COPS and plugs new on the 6th. It will reveal a weak pcm then if its ever going too.
 
yabadaba said:
I got back my rebuilt PCM after only about 8 days between sending it out and getting it back. I had several microchips that were shorted and the Solenoid circuit was shorted. I put back in (after some wrestling with it) and.....drum-roll........ all the transmission shifting problems are GONE! I thanked every God under the sun! and thank you all! I'm a proud LS owner again!
Click to expand...

Hi!

Did you replace the solenoid pack ?

best regards!
 
You must log in or register to reply here.

Members online

Total: 122 (members: 2, guests: 120)
Back
Top