E40D Overdrive help

[Averysm09]

Fury9.... When the brakes are applied that sends a signal to the trans to unlock the torque converter. If it didn't the truck would stall just like a standard trans if you didn't push in the clutch.... Now if the brake lite filament breaks and touches the turnlite filament every time to turn on that turn signal direction (left or right) the torque converter will unlock. Trust me on this.. When I rebuilt my motor the first time I had this issue. Everytime I used the left turn signal my converter would unlock and lock up. Turns out the rear left turn signal filament was broken in the bulb and touching the brake signal filament. That took plenty of hunting to find too. These E4OD trans have a few funny little quirks. Let off the throttle around 45 mph and the trans goes into coast mode. It feels like its in neutral but it isn't. Now add just the smallest throttle and watch the rpms just back up as the torque converter locks up. These are "things" the stealership wont tell you. It was a money maker for them but now the guys that knew of these things are gone... We fix our own now because of this site. These thing I learned here and will teach others about it too. My charge is free... Bet you can't get anything free at the dealer garage...

Quite an old post, but better than starting another with the same topic. I have had this issue with my trans, kicking out of O/D when I let off the throttle (not always 100% off). The PO installed LED lights in the tails. Could this cause a problem? I tried to put regular bulbs in, but it looks like they put some adapter in there that is going to take a little tinkering. It was getting dark, so there is sits.

 

[79jasper]

Mention that in your other thread.

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[trackspeeder]

Quite an old post, but better than starting another with the same topic. I have had this issue with my trans, kicking out of O/D when I let off the throttle (not always 100% off). The PO installed LED lights in the tails. Could this cause a problem? I tried to put regular bulbs in, but it looks like they put some adapter in there that is going to take a little tinkering. It was getting dark, so there is sits.

Is the tranny down shifting or is the converter unlocking.

LED lighting will cause issues with the converter lock up. The TCM need to read resistance from the brake light circuit. If it doesn't get this reading it will go crazy. LED lighting has very little resistance so you will get lock up issues.

 

[Averysm09]

Is the tranny down shifting or is the converter unlocking.

LED lighting will cause issues with the converter lock up. The TCM need to read resistance from the brake light circuit. If it doesn't get this reading it will go crazy. LED lighting has very little resistance so you will get lock up issues.

I think it's kicking itself out of OD. I can run it that way for a while throttle or not, but when at high highway/interstate speeds when I give it the beans it goes back into OD. Oddest thing to me. I also have to get it on a jack stand and spin the driveshalf to see what gears it has. I haven't the slightest.

 

[FORDF250HDXLT]

I think it's kicking itself out of OD. I can run it that way for a while throttle or not, but when at high highway/interstate speeds when I give it the beans it goes back into OD. Oddest thing to me. I also have to get it on a jack stand and spin the driveshalf to see what gears it has. I haven't the slightest.

you can find out for sure if it's unlocking the converter or downshifting if you can't tell for sure.
if your not 100% sure though,the odds are the converter is just unlocking because 3rd and od are pretty drastic change.

while driving @ 50 mph or so,push the od cancel button.the trans should downshift to 3rd.see the big change in rpms? now you now what 3rd and OD feel like at 50mph.

while driving down the road at 50mph or so,while still on the accelerator,lightly press the brake pedal.the converter should unlock.
OR you can also turn the hazard lights on.this will also unlock the converter.
now you now what a locked and unlocked converter feels like at 50mph.

once you know what's going on post back........should be in a new thread though.

 

[Plowmaster]

Quick question....does this taillight gag only apply to the newest Idi trucks....92 and up? Having problems with my 90 e40d starting in third, with a dim od light. Thanks

 

[79jasper]

If it's a e40d, it'll be affected.

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[Plowmaster]

I ask due to LEDs in the tails, but they've been in there over a year and only recently started having a problem. Seems I had it once earlier during a steering column fix, but can't remember how I cured it. Now I'm getting the problem chasing a parasitic draw, and think I have it isolated to the fusible links behind the right headlight. It's very frustrating. I've yet to ck resistance between transmission and connector at left firewall, but I've cleaned all connections more than once.

 

[FORDF250HDXLT]

Quick question....does this taillight gag only apply to the newest Idi trucks....92 and up? Having problems with my 90 e40d starting in third, with a dim od light. Thanks

when your od light is dim,you'll have high gear starts in D.2nd gear starts in manual 1 and 2.
this means your trans isn't getting power.suspect (though not limited to) the TECA relay.

your issue isn't related to taillights.

 

[Plowmaster]

Yes I've wondered about that relay...it's the only relay in that area, when I turn the key, it does click. After I cleaned the connections around that relay, the light came back on full brightness, thought I fixed it....however it still starts off in third gear. I just didn't have that specific relay when I was working on it last. I'll throw a new in there tomorro

 

[FORDF250HDXLT]

Maybe they designed it that way just to make money? But thanks for the info and I will pass it on whenever one of you guys don't get the chance to.

i know this was a dead ended question from 6 years ago,but the info never expires so....

well you said you like the KISS method in a prior post.this is cool because they made it this way for exactly what you like.
think of the converter when it locks up,just like the clutch in a manual.(the clutch discs are inside the converter)and when locked,it's just the same state as a manual trans with it's clutch engaged.(this is why modern auto's get pretty much the same fuel economy,sometimes better,as a manual trans) so just like a clutch,it needs to release.

because it's a simple way to tell the TECA to have the trans unlock the converter so it doesn't stall out and push you forward.like explained by Gary,it's need to know your on the brake so it can release.
when you come to stop with a manual,you manually press on a clutch pedal.with the auto,it uses a signal from the brake switch that you've stopped so you don't need to hit a switch or press a pedal.
so they made it this way,to keep it stupid simple.......KISS.

that was a fluke to have a element in a light blow and contact the flasher element.a very unfortunate event (not made that way) that no doubt caused Gary to say a few choice words lol.

now to take it a step further,i suppose in a way (which wouldn't be KISS anymore) is they could of used a devoted switch.....or i suppose a 3rd pin on a diode (one way electrical valve) so as to isolate whatever the brake light bulbs where doing,so as long as it's devoted switch or devoted circuit off the switch was good,then it would be better......but it's so rare and uncommon and easy to replace a bulb (which you should be sure all work anyway for safety) that you might as well keep it simple......though i suspect in some more modern vehicles,this is probably no longer the case....but it all adds to the cost of the vehicle when you leave behind the KISS method,so pro's and con's to it all i suppose.

 

[Plowmaster]

Sorry to dig at an old thread but hated to start a new one unless I can be more specific in my diagnosis. I prefer to use search and see if I can track it down before resorting to a new thread that may have been hashed out hundreds of times. I appreciate the help greatly.

 

[icanfixall]

That flasher thing on my truck was a burned out brake light filament touching the turn signal filament. This was after my rebuild. Seems every time I have the blinkers going to the passenger side my converter would lock and unlock till the blinkers canceled out. Then all was well till I used them that direction again. Took me bunch on time figuring that one out but the repair was simple. Change the tial brake light bulb. More recinetly my tach quit and I had no power to the trans. Replaced the tach and all fine for a few days. Then same issue with limp home trans not going into 1st gear. Figured it out I had a burned our fuseable link behind the passenger side battery. It had been repaired before I got the truck in 96. Had 3 blue crimp connectors in a span of 4 inches of wire... But the way I found this power issue was testing the power side of the TEAC relay. It has no power. So I temped in a jumper wire di ectly from the drivers battery and all was fine. Tach worked and shifted fine. My posting clearly shows how all this was done too. I got plenty of help from this forum too. I know very little about electrical even after a career in the power generation trade. I was not an electrician there. Welder and machinist.....

 

[OLDBULL8]

When you have a dim OD light on the shift lever, that means the TECM is not getting power (12VDC +) or the relay has dirty contacts or the connector pins are corroded or there is no power to the connector. Your Tach and speedometer have to be working also if you have the OD light back on full brightness.

It's always better to start a new thread after you've searched and can't get the problem fixed from searching.

 

[turbo elk]

Ok... stupid question... What and where is the TECA. I'm not familiar with that part.