Taurus Stalling in gear TCC solenoid cicuit p1742 error code

I hope this helps anyone having the problem with their FORD. Your car will idle fine and start good but when you place vehicle in gear it stalls/surges. Sometimes when you come to a stop light it will surge or stall as well. I have the AX4N and 3.0 dohc in my Sable. I removed the airbox and on the top of the tranny there are two wire harnesses, unplug the white one( this harness is the smaller one with 9 wires) if their is tranny fluid in the harness it will cause a false signal to the Torque converter solenoid. All that needs to be replaced is a small o ring on the inside of the tranny. The hard part is putting it in. You have to remove the side cover on the tranny. I called my transmission guy and he said he won't do it to much labor for a $1.00 o ring. I fixed this problem myself. I unplugged the harness and put gasket sealant inside and plugged the harness back in and it has worked fine for 6 weeks now. I know this is a backyard mechanic fix but nothing else wrong with my sable and i am not going to pay $900.00 to fix a o ring gasket.

Welcome to the forum, and thank you for taking the time to report details on what it took to fix your problem! You're one of the few people who's first post is to help others rather than ask for help from others.

-Rod

I also welcome you mattski77. That is a good piece of information. Might save someone some time and money in their repairs. We are looking for any information that helps anyone that visits the forum. Hopefully the information is correct or close to it. And Rod, I have not seen you have a question on repairs. Just answers. Enjoy the forum mattski77 and don't be a lurker. Jump in if you have a suggestion or answer.

My '96 Taurus - 3.0L vulcan - is doing the same thing, and my scanner says code P1742. The car has to warm up for about 20 minutes before i can put it in gear without it immediately stalling. Once it gets going it almost stalls at every stoplite. The local tranny shop says the lowend price starts at about $1200 and can go up from there. The car is worth fixing - only 70,000 miles - but I like your fix a lot better. But, I don't know what an airbox is!
Thanks for the great tip on the fix. Roberto3

The airbox is the black rectangular box that houses the air filter.

-Rod

Thanks, Rod.

my wiring harness was ok. I checked the trans oil and it was real watery. I hand-pumped out about 6 quarts and put in new synthetic mercon V. After running for a few datys it gradually improved - did not stick so often. About 2 weeks later i pumped out another 6 qts, hoping to get some of the oil that had been in the torque converter. Added 6 more synthetic. Got better still. Checked plugs. Looked like originals - gapped at about 70 thousands. Spec is for 44. Replaced plugs. Now, after another month, car runs pretty good. Problem must have been with the trans oil causing the torgue lock-up to not let go. Will change trans oil again before summer out, this time will get filter too. I think my problem is fixed. Will now change trans oil evry 2 years minimum. Thanks all.

I hope this helps anyone having the problem with their FORD. Your car will idle fine and start good but when you place vehicle in gear it stalls/surges. Sometimes when you come to a stop light it will surge or stall as well. I have the AX4N and 3.0 dohc in my Sable. I removed the airbox and on the top of the tranny there are two wire harnesses, unplug the white one( this harness is the smaller one with 9 wires) if their is tranny fluid in the harness it will cause a false signal to the Torque converter solenoid. All that needs to be replaced is a small o ring on the inside of the tranny. The hard part is putting it in. You have to remove the side cover on the tranny. I called my transmission guy and he said he won't do it to much labor for a $1.00 o ring. I fixed this problem myself. I unplugged the harness and put gasket sealant inside and plugged the harness back in and it has worked fine for 6 weeks now. I know this is a backyard mechanic fix but nothing else wrong with my sable and i am not going to pay $900.00 to fix a o ring gasket.

Thanks for this Mattski,

You described my problem almost identically minus the stalling but it will idle so low it seemed like it would stall, my goes a little further though as now the car doesn't move at all, anyways heres my story.

A couple weeks ago the weather warmed up here in Michigan, it was a Tuesday night my wife comes home from work complaining the car is running funny. As she tends to exagerate things I took the car for a ride, started it, backed out of the driveway and started driving down the street thinking she must be imagining things again hehe. I stopped and the stop sign then it happened. While stopped the car started idleing high and low and started surgeing. I put the car into park and the idle evened out, put it in drive and the same thing, once I got going it was fine, caught a side street to get home and stopped the car, took my foot off the brake and the car was surging forward - it would go then stop go then stop. I noticed it would stop doing this if I applied light pressure on the gas which idled the car faster. it would act fine then, anyways I bring the car home and in the driveway I play with it some more, my driveway is on a slight incline and I notice when in drive the car would lurch forward then start rolling back. I'm thinking it could possibly be the trans.
The next day it is colder out and the problem seemed to go away.
Two days later I use the car and drive about 25-30 miles and the engine light comes on, as it does this the problem again comes back but seems a little worse. I get the car home and scan it and it only has the 1744 code for the TCC. I research this and find it could be a number of problems.
The next day all is good again. and remains the same until last week when I get a call from the wife saying the car won't move. I go out there and get in start the car and it slips a little but grabs and start driving down the street at the point where it should go into 2nd gear it stops grabbing all together and I coast to a stop. I do this a few more times until I come to a parking lot where I can safely leave the vehicle, to get the car home from here doing what its doing would be too un-safe so I parked it. later my brother and I tow the car home.
Two days later I decide to pull the car into the yard and again it is slipping, I am able to get it back there but it seems unlikely that I will be able to drive it onto the ramps. so I just leave it.
Yesterday I go out and pop the hood, after reading several posts and with the intermittant nature of the problem I decide to check the wires first. I found the plug that matt mentions above and after a few seconds I am able to disconnect the plug. First thing I noticed was the trans fluid in the connector. I blew out the connector and plug with some air and got in the car to try it, everything started working fine then, went about 10 feet forward and reverse about 4 times. Then I left the car idleing and moved all the toys and garbage cans from the driveway and got my wife to watch the kids as they were playing in the yard, I got back in the car put it in reverse then nothing. checked the plug again and there didn't seem to be any more fluiud in there but I did notice the connector going into the trans was easy to wiggle and move. So I left it sit over night

Today I tried and it seemed a little better, I was able to drive it up the ramps with no problem. I drained the fluid which was a dark red, smelled funny, and noticed the side cover and realized how much fun that'll be to remove. I did notice some fine shavings in the pan but I read that this is normal. Then I found this post. I ordered a couple trans manuals from ebay (before reading this) and will figure what to do next.

I plan to remove the side cover and check the wiring further, I will probably go ahead and replace the tcc solenoid as it is fairly cheap. and check out the wires as well. and go from there. I feel reasonably sure that this with the fluid/filter change will fix the problem. I'll keep you updated.

Next I'

Hi All, Just reading the above topic about the TCC issues and how they can cause stalling issues. I see someone mentioning this while car is moving or in gear.
My question , would this also cause idle issues in park? Dieing in park?

Without a decoder I have led myself up the iac valve of which replacement had no results.

I am now reading in your site about possible upper stream 02 sensors.

I have the egr valve blocked, cleaned out carbon in the cavity in front of the throttle body.

I have at least 30 psi fuel pressure, motor does not miss upon a load.


Any ideas? This is a car that is in our family and will probably be sold, not sure. Its a 98 tarus DOHC, runs well or did before the little cold spell. Plugs are good, getting a full fire signal thru plug wire tester.

I see thru the forum many folks have this issue be not positive fix yet.

I will be looking at this transmission plug issue with the AT fluid shortly.

Howdy from West Texas and good nite for now. Check you in the morning. thanks.

Welcome to the forum! A BIG THANK YOU for searching the forum before posting or starting a new thread!!!

If the TCC is remaining locked, it would cause stalling with the car in gear but not stalling in Park or rough idle in Park.

What specifically are your symptoms? Are you primarily having rough idle and stalling in park? Do you also have a rough idle when driving? How old is the battery? Have you checked and/or replaced the spark plugs, spark plug wires, and fuel filter recently? You mention the plugs are good, is that based off the spark tester or did you pull them and look at them? Have you checked for vacuum leaks? Were there any signs of an issue prior to the current symptoms such as decreasing fuel economy? Has the Check Engine Light come on when driving the car?

I don't recall if the 1998 DOHC in the Taurus uses an electronic Intake Manifold Runner Control (IMRC) or a vacuum-actuated IMRC. If the IMRC is not closing at idle and low RPMs that will cause a rough idle as well.

-Rod

Thanks Rod for the reply. This little issue is beginning to get the best of me. I have much mechanical old school knowledge on autos,(old service writer) and some limited electronic stuff. I installed a electronic multiport set up on my old 57chevy and it had much of what is on the Tarus, ecm, air mass , iac, water and air temp, etc. So let me fill your ear here.
1998 dohc v6, up until it got cold here in Texas, 20°, it ran well according to my kids. For a reason I swapped out my new Yukon and took the Tarus. Soon after when I was getting ready to drive it , I would go out and warm it up, I would come back and it had died, so I restart easily and leave running, about 3 or 4 min later it would die again. Restart and be on my way but after it warmed up , it would die in gear at the light and restart with the turn of the switch, no issues. Sometimes I could watch the tach and I could see the rpm drop but the blip of the throttle would bring it back.
I will add that at one point in time the I got TCC codes but I have not done anything about this as going thru the trans will probably exceed the value of the car , just like my old 88 tarus(still running) .

So up to this point , I check plug wires with a pencil fire tester, all show solid constant fire at idle and increases as rpm rises.

I did pull the plugs to find they were the orginals (little blue rings around the porcelian). They had .085 gap which I thought was hi so I replace them (pulled intake). No change in problems.

Knowing what the old egr valves used to do to a chevrolet, I totally blocked off the egr with a steel shim plate, got it all back together and started to let warm up, still quivers and dies after 2 or 3 min.

Suspecting fuel issue, I unplugged the fuel bypass vacumn hose and retried, Still no change, would still quiver and die after 2-3 min.

I have an old hi pressure tire guage and hose that I tested the fuel at the time motor was running and about to quiver, pressure wrapped my 15# gauge twice , so I figured I had more than 30 psi on the line.

I have changed th fuel filter at one time but probably need to look at it again.

I pulled the throttle body off, washed out with Seafoam and a soft tooth brush. I cleaned out the carbon at the bottom front passage where the egr gasses come thru. I looked into the IAC manifold port and it was clean. The internal IAC valve ports were also clean but when I blew out with air , I notice a flake of something fly out , could not determine what it was. Looking at the stem or valve sealing surfaces, I suspected it may be part of this surface . Thats one other reason I took the Autozone IAC

From there I started looking at the IAC testing. On line I found a test procedure that told me the ohms on the two pins of the valve can be checked. The range was something like from 0 to .05 ohms. Mine teted 8.4
I went to Autozone and got one of theirs and tested it , it tested 9.8-10.4 ohms. I discussed this with the counter man and compared testing procedures, he brought out his Autozone specs. Told me if it did not work, to return it. So I am waiting on this.

Cold weather killed my battery yesterday so I got another and car fired up easy but letting to warm up, with the egr valve blocked( plate), engine still dies after a while.

Today , I will remove the air box again, look down at this trans terminal connector Mattski77 mentioned, but all this happening in park does not make me feel like this is the problem, in gear maybe .

I will go back to Autozone and get them to pull codes. I want to see if his scan tool says anything about his new IAC. Maybe it will reveal newer codes. I really dont want to purchase a scan tool as they cover only up to 2002 and I am getting too old to mess with this stuff. I was going to take car to a shop , maybe a Firestone store and pay to determine what the issue is.
I would even replace plug wires if I could get any valid reason to. Beyound that , whats next? Ignition modules, MAS?

I don't suspect any vacumn leakes, although I did have some loose capillary hoses that came out of their boot, just under the intake. Motor idles so smooth when running up until it wants to quiver and die. With engine running, I spary carb cleaner around these hoses and notice not increase in rpm.

Did I do wrong by blocking off EGR just for testing? IMRC? What is this and where is it?

Also, what does the EGR vac solenoid do? What function would it do even if I have the egr valve blocked off ( plate between valve and manifold)??


Appreciate any input you can provide.

Don Dabbs
Two Dog Town in Texas

The valid reason to change the spark plug wires would they are almost definitely as old as those spark plugs you took out. If the spark plugs were worn out, the wires probably are too. New plug wires would probably cost you less than a new IAC and may be money better spent, especially if you plan to keep the car once you get it fixed.

Does the vacuum diagram under the hood help you determine where those loose capillary go?

You probably are not causing a problem with the EGR removed an blocked off, but it will likely trigger a code for the Differential Pressure Feedback EGR (DPFE) and may even introduce a vacuum leak when the EGR solenoid flows vacuum to attempt to open the EGR valve. The DPFE provides signal to the EGR vacuum solenoid to provide vacuum to the EGR valve to open and close the valve. If you have a leak in the line from the EGR solenoid to the valve or failed to cap it off, you will have a vacuum leak when the DPFE signals the solenoid.

The IMRC is a motor, either vacuum or electric, that opens a set of butterfly valves in the intake manifold at higher RPMs (typically around 3500 rpm) to flow air through a secondary set of manifold runners. I don't know if the '98 DOHC engine still utilizes these, but I suspect it does. Similar to a stuck open EGR valve, if the secondary butterflies are not closing at idle they will cause a poor idle condition.

You're in a bit of a catch 22. To properly diagnose this without taking it to a shop you will need to come up with (buy, borrow) some new tools. While the tools are not always inexpensive, they may prevent spending money on items that don't fix the problem (fuel pump, IAC, EGR, DPFE, etc.) and pay for themselves quickly. Plus most of these diagnostic tools (fuel pressure gauge, vacuum gauge, OBD-2 scan tool) are versatile and will be able to be used on pretty much any modern internal combustion engine. There are planty of OBD-2 scan tools out there that work on much more recent vehicles than 2002 model year, and many of them are updateable over the Internet.

-Rod

Again, Rod thank you for the quick reply.
New wires it will be but I suspect this is not the issue. Once I get this done I will go back to look at a scanner, I was hoping to find an inexpensive data reader as well as scanner for codes, so I can see the values that each component sends.

The vacumn diaphram that is attached to the fuel regulator, runs into a "L" boot that is also connected to the egr valve. That boot comes directy off the intake manifold.

The IMRC throtte blade you speak of , in the intake, I saw them, I was trying to determine what activated them but did not go further, they were gummed, I suppose spray seafoam will help this? And I presume all the debris will wash down to the cly ?? Bad??

So I will pick up the wires and filter as these are maintenance items. I hope to hear more from you on cleaning these IMRC blades.

I guess its off with the manifold again. Not a biggie. Just a hassle.

What about ing modules?

Where do I obtain vacumn hose routing just to trace out, making sure something I am not missing.
Again, Thanks a ton.

Don Dabbs

Howdy All , Rod, Just thought I would get back with the audience here that may be reading this thread.

I picked up plug wires yesterday and began to install them. I got curious again about the throttle plates , down inside the lower intake manifold you mentioned. I pulled the intake for the 3rd time. Dismantled the throttle body and cleaned it with Seafoam spray and a soft tooth brush. I understood that regular choke or carb cleaner will remove some of the throat coatings.
I preceded to spray seafoam into those throttle plate bores. I cleaned up the intake mating surface and applied a smear of lube to help the seal.
Upon hooking up vacumn hoses, I found my problem. The large 3/8's horseshoe bended hose from the lower intake to the pcv valve was either melted or so soft I punched it with my finger. There was another same sized hose in vertical mount from the intake to a steel line going down below my eye level . It was split where it could not have been seen.
I also noticed another red capilary line that had broke also.

Long story short, I got all together, removed the egr block off plate, put it all back together and started it up.
No more stalling, no more long idle dying during warm ups. I even took the new IAC valve back off and put the old one on. All is good.

So, I went to Autozone to return the new iac valve and asked to check codes. There were none. Not sure if there ever was because I never made it to the store, I was presistant to fix it the old way, just by checking. I am sure it will get me one day and I will break down and purchase a scan tool, but not this time.
This is the 2nd of 3 Tarus cars, 88, 98, 2006 of which all have proven their ability to keep running.

Again I hope someone who is reading this, might gain something and I do appreciate you feeding me the information.

Again Thanks

Don Dabbs