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I'm not sure if this has anything to do with my tranny problems but I suspect it might. I was driving down the Beeline Highway in Florida about 60 miles an hour when I looked down and my voltmeter was reading over 18 volts with the needle pegged. I pulled over assuming my voltage regulator had failed. I couldn't get the plug out of the alternator because I'm disabled so I cut the belt off the alternator. I wasn't too concerned with getting home because I have two Optima 1125 CA deep cycle batteries.
When I went to pull back out on the road the truck wouldn't move. Eventually I dropped it down to 1st qear and it drove fine I manually shift into second and realized I was actually in 2nd to start with even though the indicator said first. I then went ahead and pushed up into drive it was able to make 3rd gear and then 4th. I also noticed that the overdrive is turned off I hit the switch to turn it back on and nothing.
My question is this, is there any sort of Electronic Module in this transmission that controls the shifting that could have been fried when my voltage regulator failed? I'm an above-average backyard mechanic who knows the one thing that every backyard mechanic needs to know, that is how to say "I have no idea how this works" that is exactly the case here. have no idea how these automatic transmissions work! Any knowledgeable answers based on experience would be appreciated.
No Electronic Module inside the transmission that controls the shifting.
All you have in the transmission is solenoid valves and a thermistor to report the temperature.
While the transmission has no module inside of it, there is a computer that controls the transmission shifting. Chances are you actually only had 2nd and 4th gear, as that what the E4OD defaults to if it has no input from the computer. Positions "1" and "2" on the shifter will give you 2nd, and "D" will give you 4th.
I'd start by checking all fuses. But if your "O/D Off" light was stuck on and didn't respond to button pushes, I suspect your transmission computer died.
But there is an electronic PCM (powertrain control module) in the truck just like any other truck of this vintage, only difference is it controls the trans only.
Off topic here but why are you using deep cycle batteries in a truck? Deep cycles are not intended for starting applications, they are designed for long term, low power discharge (RV campers, trailers, etc) whereas actual automotive grade batteries are designed for high current demand. Not suggesting it is related to your problem but I had to argue with people back in my auto parts days who tried to buy them for their truck/car, they just won't last long like that. Deep cycles are not designed for starting automotive engines.
Off topic here but why are you using deep cycle batteries in a truck? Deep cycles are not intended for starting applications, they are designed for long term, low power discharge (RV campers, trailers, etc) whereas actual automotive grade batteries are designed for high current demand. Not suggesting it is related to your problem but I had to argue with people back in my auto parts days who tried to buy them for their truck/car, they just won't last long like that. Deep cycles are not designed for starting automotive engines.
The simple answer is because I already owned them, and they aren't actually deep cycle batteries. Sorry for the misinformation.
Those two batteries have been in my 1987 Mako 231, my 1969 Peterbilt 359 and a crane They are a dual purpose Optima SC31DM's. Most people don't realize that Optima batteries are available in deep cycle, hard cranking, and dual purpose. These are dual purpose, they are both deep cycle and hard cranking. They work great.
These two particular batteries have been completely discharged hundreds of times and still provide 1125 CA/900 CCA each. If you think that a 7.3 IDI has to spin pretty fast to start you need to try to start a 1969 Detroit Diesel 8v71 NA. Unfortunately, if I keep them in this truck I'm going to have to lower the battery trays because they're too tall to shut the hood completely.
The one on the passenger side was actually boiling and the case was soft when I pulled over and cut the alternator belt off. That tough battery still takes a full charge. I love Optima Batteries but you have to buy the right one. I agree with you that I have seen many many people put straight deep cycle batteries into hard starting situation and ruin them I also have seen many people put hard cranking versions into deep cycle situations and ruin them. That's why I love the dual-purpose versions of their batteries and specifically the blue top SC31DM's. They are tough dual-purpose batteries that have both types of top posts and also designed to take a massive beating. I personally believe they are perfect for any diesel that actually goes off road.
Last edited by BIG ZILLA; Nov 5, 2017 at 01:17 AM.
Reason: Oops
Before you buy a new computer you might try "magic".
Disconnect both of those big ole batteries. Hit the brake pedal several times and let it sit overnight. Hook it up the next day and see what you have.
Get a new alternator belt.
Try to check for codes. If it won't do a test, it's dead.
I greatly appreciate the advice and know exactly why you felt the need to post it. But I actually did that before I ever posted the question. I checked for fuses that had been fried and disconnected both batteries for about 12 hours in order to do the quote "magic reset" . I can't tell you how many times I've driven 30 miles to my mother's house just to turn her cell phone, cable box or iPad off and back on again. Lol
Thanks for the thought though!
WAIT! PUMP THE BRAKE??
Please explain. What would be the purpose for that? Sometimes I'm not as smart as I think I am. LOL
Last edited by BIG ZILLA; Nov 5, 2017 at 02:28 AM.
Reason: Oops
I'm not sure if this has anything to do with my tranny problems but I suspect it might. I was driving down the Beeline Highway in Florida about 60 miles an hour when I looked down and my voltmeter was reading over 18 volts with the needle pegged. I pulled over assuming my voltage regulator had failed. I couldn't get the plug out of the alternator because I'm disabled so I cut the belt off the alternator. I wasn't too concerned with getting home because I have two Optima 1125 CA deep cycle batteries.
When I went to pull back out on the road the truck wouldn't move. Eventually I dropped it down to 1st qear and it drove fine I manually shift into second and realized I was actually in 2nd to start with even though the indicator said first. I then went ahead and pushed up into drive it was able to make 3rd gear and then 4th. I also noticed that the overdrive is turned off I hit the switch to turn it back on and nothing.
My question is this, is there any sort of Electronic Module in this transmission that controls the shifting that could have been fried when my voltage regulator failed? I'm an above-average backyard mechanic who knows the one thing that every backyard mechanic needs to know, that is how to say "I have no idea how this works" that is exactly the case here. have no idea how these automatic transmissions work! Any knowledgeable answers based on experience would be appreciated.
When the E4OD loses power,the following happens:
1.The OD light glows dim (approx half it's normal brightness when the cancel switch is normally pressed) This loss of power is when the TECA itself loses power.
2.The OD cancel switch is unresponsive and inactive.
3.D becomes high gear. OD/4th.
4.Manual 1 and 2 shift positions,both become 2nd gear.
5.Reverse remains unaltered (it's never controlled electrically in the first place).
6.There is no 3rd gear when manually shifted from 2nd then to D to limp the truck home.Though it feels this way,it's actually only converter unlock and OD.
The main (though not the only) cause for this is the TECA relay or the fuse which feeds it has failed.Both are located in the engine bay.
Tip; One of the other relays,such as the horn relay can be swapped in place of the TECA relay so you wont need to limp home.
Tip 2.A common relay sold at auto stores will work.Simply snap off the universal screw/bolt mount,if your truck is a 92+ so the lid of the power distribution box closes.
Although subfords pic here,shows a 9th gen gas truck's PDB with "PCM" locations,FORD simply used the same wiring on their IDI/E4OD trucks to feed the trans control unit,so in place of "PCM" pretend it says "TECA" (trans control unit) and insure power is supplied through these fuses (specifically the U and I locations) and relay.
If you don't find power at your relay socket (less common) then,suspect a blown fusible link.This is located at the fender mounted starter relay.
If you have power passing through the relay socket to the TECA,then either there is a bad ground to the TECA or it failed.Pretty uncommon.If it failed,be sure to use an upgraded TECA if the IDI truck is pre '94.
These reman units are around $100 for our IDI/E4OD trucks so they're pretty affordable.No point in tossing good money away to test though.Ensure the unit is properly grounded and supplied with power.
Lastly,ensure the solenoid pack plug connector is clean and fully inserted.Just because your TECA has power,doesn't mean power is getting to the solenoids.
WAIT! PUMP THE BRAKE??
Please explain. What would be the purpose for that? Sometimes I'm not as smart as I think I am. LOL
Part of the whole voodo/magic thing. Any power that might be captive gets grounded through the brake light. Makes sure the voltage is at zero.
In reality the power distribution and grounds are becoming more of an issue as these vehicles age. As are alternators. They were never a good design and as they are reconditioned by globalist multinational hacks using third world labor they aren't any more confidence inspiring.
When the E4OD loses power,the following happens:
1.The OD light glows dim (approx half it's normal brightness when the cancel switch is normally pressed) This loss of power is when the TECA itself loses power.
2.The OD cancel switch is unresponsive and inactive.
3.D becomes high gear. OD/4th.
4.Manual 1 and 2 shift positions,both become 2nd gear.
5.Reverse remains unaltered (it's never controlled electrically in the first place).
6.There is no 3rd gear when manually shifted from 2nd then to D to limp the truck home.Though it feels this way,it's actually only converter lock and OD.
The main (though not the only) cause for this is the TECA relay or the fuse which feeds it has failed.Both are located in the engine bay.
Tip; One of the other relays,such as the horn relay can be swapped in place of the TECA relay so you wont need to limp home.
Tip 2.A common relay sold at auto stores will work.Simply snap off the universal screw/bolt mount,if your truck is a 92+ so the lid of the power distribution box closes.
Although subfords pic here,shows a 9th gen gas truck's PDB with "PCM" locations,FORD simply used the same wiring on their IDI/E4OD trucks to feed the trans control unit,so in place of "PCM" pretend it says "TECA" (trans control unit) and insure power is supplied through these fuses (specifically the U and I locations) and relay.
If you don't find power at your relay socket (less common) then,suspect a blown fusible link.This is located at the fender mounted starter relay.
If you have power passing through the relay socket to the TECA,then either there is a bad ground to the TECA or it failed.Pretty uncommon.If it failed,be sure to use an upgraded TECA if the IDI truck is pre '94.
These reman units are around $100 for our IDI/E4OD trucks so they're pretty affordable.No point in tossing good money away to test though.Ensure the unit is properly grounded and supplied with power.
Lastly,ensure the solenoid pack plug connector is clean and fully inserted.Just because your TECA has power,doesn't mean power is getting to the solenoids.
If anyone can post a pic of the panel I'm supposed to have (1991) over the left front fender I would appreciate it. mine apparently has been at the wrong end of a WW2 flame thrower..
When the E4OD loses power,the following happens:
1.The OD light glows dim (approx half it's normal brightness when the cancel switch is normally pressed) This loss of power is when the TECA itself loses power.
2.The OD cancel switch is unresponsive and inactive.
3.D becomes high gear. OD/4th.
4.Manual 1 and 2 shift positions,both become 2nd gear.
5.Reverse remains unaltered (it's never controlled electrically in the first place).
6.There is no 3rd gear when manually shifted from 2nd then to D to limp the truck home.Though it feels this way,it's actually only converter lock and OD.
The main (though not the only) cause for this is the TECA relay or the fuse which feeds it has failed.Both are located in the engine bay.
This is EXACTLY my situation right down to the dim OD light.
Can someone PLEASE help me find this relay, "in the engine bay" is not enough for me.
An help with the above photo would be good also.
Thanks.
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