Need help, 1800 miles from home, and getting DTC p0785!!!!
08-22-2011, 10:39 PM
#1
Need help, 1800 miles from home, and getting DTC p0785!!!! Hey guys, so as the title says, I'm in California, 1800+ miles from home, and today my trans started not shifting into OD, and starts out in 2nd. I have my scanner with me and it's throwing a p0785 code, 3-2 shift solenoid problem. If I clear the code out, it will work, but then at some time it will shift hard, and the code will come back. I've done ALOT of searching and have pretty much decided I'm going to change the 3-2 shift solenoid (already went to the dealer and picked one up), but I can't seem to find anything that shows which solenoid is which. Does anyone have a pic or diagram that shows this? I have a service manual at home, but that doesn't do me any good here! Any help would be appreciated!
BTW, it's the '33 in the pic in my sig. Never given me any trouble until now. It just turned over 50,000 miles on this trip, so the trans has about 55,000 on it total.
BTW, it's the '33 in the pic in my sig. Never given me any trouble until now. It just turned over 50,000 miles on this trip, so the trans has about 55,000 on it total.
08-22-2011, 11:47 PM
#2
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The two shift solenoids are right next to each other and are identical. The 1-2 solenoid is the one right next to the forward accumulator cover and the 2-3 is the one next to that. Also meek sure the shift valve moves freely while you're in there.
08-23-2011, 04:54 PM
#4
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Try this , hope it helps, been there and done that ( but only 1100 miles)
Johnny
>>>> ps: may try both links also
http://www.ls2.com/boggs/a4/controla...eplacement.htm
http://www.youtube.com/watch?v=OGckmJK2rNQ
Johnny
>>>> ps: may try both links also
http://www.ls2.com/boggs/a4/controla...eplacement.htm
http://www.youtube.com/watch?v=OGckmJK2rNQ
Last edited by SS SLP2; 08-23-2011 at 05:03 PM.
08-23-2011, 11:15 PM
#7
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Depending on what you are using to control the trans....the stock computer simply needs a quick key off condition to reset your "limp mode". I used to get it all the time when I went from a 3200 to a 4k converter. From my understanding it means the computer see excessive rpm flare after it has commanded the 2/3 shift so it thinks the shift did not take place. An aftermarket converter will trigger this code.
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08-26-2011, 12:54 AM
#8
Depending on what you are using to control the trans....the stock computer simply needs a quick key off condition to reset your "limp mode". I used to get it all the time when I went from a 3200 to a 4k converter. From my understanding it means the computer see excessive rpm flare after it has commanded the 2/3 shift so it thinks the shift did not take place. An aftermarket converter will trigger this code.
The day before yesterday, I drove the car about 130 miles or so, and it didn't give me any trouble at all, yesterday I drove it only about 60 miles or so, but some of it was in LA's awesome traffic, and no problem at all. Today, in the mountains, the problem came back. I'm thinking the problem is heat related, because when the problem first started, I was in the Palm Desert when the actual temperature was around 115*. The last two days it wasn't nearly that hot, and today wasn't either, but I was in the mountains on some pretty steep inclines, and the trans temp was hovering around 230* when the problem came back.
So my question now is, could the solenoid be just sticking when it gets hot? and if that's the case, why does it un-stick when the code is cleared?
Anyone know??????
08-26-2011, 01:50 AM
#9
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No, the condition you are seeing "starting in second" is being commanded by the computer. It deemed something inappropriate in the function of the trans, so it puts the trans into "limp home" mode which has ALWAYS consisted of (for me) exactly: 2nd, 3rd, and no lockup. No first, fourth, or lockup. I been in it a million times. You get one gear shift between 2/3 and that's it. I have also noticed that you must leave the key off for a few seconds for it to reset. Restart too quickly and it will still be "broke".
When you clear the code, you are clearing the commanded "limp home" mode and normal function resumes.
When you clear the code, you are clearing the commanded "limp home" mode and normal function resumes.
08-26-2011, 11:51 PM
#11
So do these solenoids just "go bad"? I mean I understand that anything cacan, but just wondering why the PCM is commanding limp mode. Is this a common problem, and I've been lucky in the past and never had to deal with it? Is there a decent probability that changing the 3-2 solenoid will fix it? If I was at home, id just do it, but that's the problem, I'm still about 1800 miles away from my garage.
08-27-2011, 12:08 AM
#12
Chances are the solenoid will not repair it being as it is an intermittent problem. Most likely it is a condition relative to the 3/2 valve or hydraulic circuit itself. This is a known condition that most builders address when they go into the unit for a rebuild.
The good thing is it's probably just a minor fix with an updated spring on the valve. The bad thing is you're a bajillion miles from home.
Manage it as best you can and when you get home that would be a good time to consider freshening up the unit. There's an outside chance the 3/2 valve bore is worn and allowing fluid to bypass.
You might consider getting your hands on a new valve body and swapping it out before heading home. But, without seeing the unit it's a bit difficult to say which direction to advise you.
Feel free to call me if you like. I'll be in the shop all day tomorrow.
g
The good thing is it's probably just a minor fix with an updated spring on the valve. The bad thing is you're a bajillion miles from home.
Manage it as best you can and when you get home that would be a good time to consider freshening up the unit. There's an outside chance the 3/2 valve bore is worn and allowing fluid to bypass.
You might consider getting your hands on a new valve body and swapping it out before heading home. But, without seeing the unit it's a bit difficult to say which direction to advise you.
Feel free to call me if you like. I'll be in the shop all day tomorrow.
g
09-02-2011, 07:18 PM
#13
Thought I'd check in and update this and let everyone know that I did make it home, and to thank everyone that responded with suggestions. I have not done anything to it yet, and got it home by clearing the code to get it to go into OD on the highway. I hope I didn't do any more damage to it by doing that, but figured if it did, it was still cheaper than a tow bill from California! In all, I put 5000 miles on the car so that means I drove it" messed up" for 3200 miles, so I am crossing my fingers that it will be an easy fix. Since I have the part and was going to change the fluid and filter when I got home anyway, I'm going to put it in and try it. I report back with my findings. And thanks again for the advice, when I first made the post I was kind of on the verge of panic mode not knowing if it was going to eat it's self soon or not!
09-03-2011, 07:52 AM
#14
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I have seen quite a few of those solenoids fail over the years and hydraulically test even new ones in the shop I work in. As Gilbert said there is a spring in that bore that likes to break as well. In the TTK overhaul kits (Toledo Trans Kit) this spring is actually included and should be replaced when units are overhauled. You can get the valve out of the bore to inspect the spring in the 96(also some late 95 bodies) and later valve bodies without removing the VB. Pretty sure that I have a few extra's laying around if you need one. Just let me know. HTH Vince
02-29-2012, 10:48 PM
#15
I have seen quite a few of those solenoids fail over the years and hydraulically test even new ones in the shop I work in. As Gilbert said there is a spring in that bore that likes to break as well. In the TTK overhaul kits (Toledo Trans Kit) this spring is actually included and should be replaced when units are overhauled. You can get the valve out of the bore to inspect the spring in the 96(also some late 95 bodies) and later valve bodies without removing the VB. Pretty sure that I have a few extra's laying around if you need one. Just let me know. HTH Vince
Last edited by ls1nova71; 02-29-2012 at 10:54 PM.
03-01-2012, 06:27 AM
#16
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Yes it is directly behind the 3-2 solenoid. If you find that the spring is broke I could easily send you one. Just shoot me a pm with your shipping info and I'll drop on in the mail for you. HTH Vince
03-01-2012, 08:33 AM
#17
Thanks man! I appreciate thaw offer. But not to be asking all kinds of stupid questions, when you say take the valve out of the bore to check the spring, do I just pull the solenoid and in the bore the valve will just pull out? Or is there a trick to getting it out?
03-31-2012, 05:57 PM
#19
Back to the top one more time! And hopefully the last time! I'm almost hesitant to post anything for fear of jinxing myself, but I dropped the pan and there was nothing out of the ordinary in the bottom of it, and the fluid looked nice, so took the solenoid out, pulled the little plunger thing out and inspected the spring, it was good, and the plunger moved freely, so I put the new solenoid I bought in Cathederal City California, in it, put a new filter and fluid in it and it's as good as new! Since then I drove it to Fort Worth Texas and back, and around town so I've put about 1500 miles on it. 
I'm still keeping my fingers crossed for a little while longer, but I think I got it. Big thanks to everybody who offered help on this, I was truely lost as to what to do, and you guys really helped me out! 
I'm still keeping my fingers crossed for a little while longer, but I think I got it. Big thanks to everybody who offered help on this, I was truely lost as to what to do, and you guys really helped me out! 