E4OD torque converter unlocking

[cowman79]

I am starting to have some trouble with my trucks torque converter not locking up properly. About two months ago it didn't lock up when i first started driving then after it would warm up and it would start locking properly. Now it is almost every time I drive it that it doesn't lock up properly. I can drive the truck for several miles and it will start locking up properly. I can turn the truck off get right back in the truck and it will not lock properly. I have a transmission temp gauge on the truck and the lock up is not dependent on the actual transmission temperature. I feel like this is an electrical problem but not sure where to go from here. The truck is not showing any codes. The transmission was a low mileage transmission that was put in about 6 months ago. The truck shifted seamlessly for a few months and then started the unlocking problems that I had before the transmission was put in the difference is that before the transmission was put in it was throwing codes. I think this was related to a bad connection on the PSOM because I disconnected and cleaned the connections on the back of the cluster and it quit throwing codes and started acting properly until recently. The transmission was replaced because the torque converter had destroyed it self after towing a large load of lumber.

 

[trackspeeder]

Check for codes.

TC lock and unlock randomly is a sign of a faulty TPS. Could be out of range, or going bad.

 

[cowman79]

The tps only has about 15000 miles on it and it was a ford sensor.

 

[OLDBULL8]

With a cold trans. you will NOT get lockup until it reaches about ~70*F, that's to protect the TC, the TOT (Trans. Oil Temp) is mounted on the shifting solenoids. The TC is the main generation of heat. Check the fluid level with the trans. in Park and hot, an over and/or low level is ******* the TC. You may still have connection problems, start by cleaning them again, check the connection on the trans. also.

 

[cowman79]

How many connections are there and where are they located

 

[icanfixall]

What is the voltage the tps is set for. Usually I find the 1.2 volts key on but engine off setting works best. This is done on a warmed up engine too. As for the electrical plugs controlling the trans there are 3 of them under the master cylinder area. Then there is one on the passenger side near the exhaust pipe behind a heat shield. The shield MUST be in place or the heat will ruin that plug. Then on top of the rear of the trans if you have a cable speedo is an electrical connection. Might be 2 of them up there. Finally there is a connection on the drivers side of the trans and its called the mlps. Manual lever positioning switch... Hope this helps. If there is any corrosion in these plugs all kinds of hell happens like whats going on with you. Contact cleaner thats harmless to plastic cleans them out but try using a tooth brush too. The tooth brush wont ground the circuts. Then allow to dry well and use dielectric grease to fill the plugs. Then you wont have any moisture getting in causing corrosion. Now one more item. The food brake has an unlock circuit on it. To test it drive in od or 3rd gear and lightly press on the brake peddle. You will feel the converter unlock. Reason for this unlock is when you come to a stop if this did not unlock the converter the engine will die. Might check that too. Now a final note. If a tail lite bulb has burned out the blinker circuit and the filament has fallen on the brake like filament every time the blinker works the converter will lock and unlock... Found this out the hard way after I rebuilt my engine and on the first test drive I got the lock and unlock when the blinker was on. Scared the holly crap out of me. I thought the worst had happened with my wiring mess. So there you have all the possibilities I know of. This information cost me dearly too. My oem trans was doing the lock unlock after about 45 miles of driving. Made me crazy. One Ford dealer changed the tps for $200.00.. Same issue. Another told me the trans was shot without even test driving the rig. Still another said the trans computer was shot and changed me $600.00 to replace it. Still had the issue. An all Datta mechanic in Phoenix told me do bring it to him and he would fix it. So I did. Another $100.00 for a new tps and right at the cali az border it happened again. Replace the trans with a Jaspers trans. Worked well for about 4 months then it came back. Over on the other site a member told me to clean the electrical plugs like I'm telling you. Problem fixed for less than $6.00 after spending nearly $4000.00... So mad as hell I contact Ford factory reps and guess what.. they told me no refund because I went to 3 different dealers and should have stayed at the same dealer till it was fixed.. Well F.Y.. Ford. You lost a loyal customer right there. They have never seen my rig in their bays since that.. Of all the nerve...

 

[cowman79]

The last time I checked the tps voltage it was. 1.19 with the engine off. Also thanks for the info about the plug locations. I am thinking that the problem has to be the computer unlocking the torque converter because it is not setting a code. I really wish we could monitor live data with these controllers it would make troubleshooting simpler.