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Discussion Starter · #1 ·
Mark you seem very knowledgeable about E4od transmissions so I’m hoping that you might be able to help me out. I’m probably going to give you more info than needed but Im doing so just in case it helps. I traded a four Wheeler for a 97(obs) 7.3 powerstroke with an E4od trans. When I first got the truck it didn’t run. There was wiring all strung out around the ecu and main fuse box under the hood. I got an electrical diagram and started tracing the wires. It turned out my ecu had a bad microprocessor, so I got it repaired. Truck started right up. After getting it running the tranny was acting very erratic, sometimes it would shift super hard, sometimes it would shift into what felt like neutral. I tried running seafoam hydra trans cleaner through it. It seemed better but then soon after not. I also noticed that the trans was leaking a ton of trans fluid. The two lines that go to the cooler were cut and spliced with rubber lines. I fixed that with flaring and compression fittings. The pan was leaking so I ordered the reusable metal center gasket. Still leaked so I ordered a new pan. Then come to find out there was no gasket between the trans and extension and extension and transfer case, I fixed that. I finally got all the leaks fixed. It still was shifting erratic. I did a line pressure test and the results were i was getting WOT pressure all the time. After doing some thinking I thought maybe the computer was freaked out so unhooked the batteries and let the computer reset. No change in shifting but didn’t do another line pressure test. So next step I took the solenoid plug off and checked incoming voltage. Both voltage feeds were getting full voltage. And the pressure solenoid was like 5 volts. I did notice that the plug had some moisture in it so I blew the moisture out and got it dry. I also did a resistance test on the solenoid pack, they were all 18.5 ohms except for the pressure solenoid which was 4 ohms. I put everything back together and drove it. Now the tranny does so much better but now I still have one issue it is doing. Under normal or light load the tranny shifts fine. If I go into WOT It will not shift out of first into second. Or i WOT and it down shifts into first it will not shift or goes into what feels like neutral. Any help would be greatly appreciated
 

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You should start by reading the codes. Forscan is a good way to do it. You can download it free at forscan.org. You'll need an ELM327 adapter. I bought one from Amazon for less than $30.

Or you could take it to a good independent shop or a Ford dealer to read the codes. The places that read codes free CANNOT read these codes.
 

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Discussion Starter · #5 ·
So after running my codes tonight there was literally thousands of codes when I first plugged the scanner in. I cleared the codes because it appeared most all of them were from when the pcm was bad. After clearing them I took the truck for a drive. Honestly it acting completely like a normal truck until I went WOT. It still didn’t shift into second and after doing that the third time it didn’t want to shift anymore. So I got it home ( I was only half mile from the house when I was doing that) and scanned the codes again. No codes were present but my check engine light was on ( it never went off even after I cleared the codes). So my guess is that I’m gonna need to rebuild this trans? But I do have one question. If you look at the pic I posted, isn’t my pcm a PWM type? I’m pretty sure my solenoid pack is a on/off type. I will post pics of my solenoid
 

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If you look at the pic I posted, isn’t my pcm a PWM type? I’m pretty sure my solenoid pack is a on/off type.
All PCMs and solenoid bodies were on/off until late 1999. If yours is older than that (I think 1995 qualifies as older than 1999....) it is an on/off. Why do you think it is a PWM?
 

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Discussion Starter · #8 ·
Just because I saw PWM under my obd ll bus. After doing some searching it appears as tho that is how the ecu checks the sensors. I’m starting to feel hopeless that my trans issue can only be fixed by a rebuild. My ohms on my solenoid packs are a little low compared to what I found online values are saying. Actual 18.5 vs 20-30. I’m thinking about ordering another one and trying it. I can’t see it hurting anything since if I have to rebuild the trans I will be buying a new one anyhow. Is there anything you could think of that might cause this other than needing rebuilt or bad solenoid pack?
 

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After doing some searching it appears as tho that is how the ecu checks the sensors.
No, it is not. PWM means Pulse Width Modulated. It is the way the PCM controls the solenoid. Instead of on/off it runs at a percentage of full on. It does this by pulsing the solenoid on and off very, very fast.

I’m starting to feel hopeless that my trans issue can only be fixed by a rebuild.
Spend the money. It's only a few thousand dollars. And chances are you'll still have the same problem. We can work on that later.

My ohms on my solenoid packs are a little low compared to what I found online values are saying. Actual 18.5 vs 20-30. I’m thinking about ordering another one and trying it.
Almost certainly a waste of money, but at least it isn't my money. Without codes, you're just shooting in the dark. You have NO IDEA what's wrong, and neither do I. If I knew what all the codes were instead of you wrongly dismissing them I could help. Without codes, all I can tell you is that something is wrong.

You do not have any codes stored from the bad PCM. If the bad PCM was unplugged from the truck all codes were cleared. If you repaired the PCM without it ever losing power from the truck's batteries, it MIGHT have saved the codes.

Without the codes, all I can tell you to do is replace everything. Replace the transmission, the entire wiring harness, and the repaired PCM. That will probably be better than a 50/50 chance of fixing what's wrong.

You really need to read the codes. It's not repairable without codes.
 

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Discussion Starter · #11 ·
These were all the codes when I first plugged my code reader in. Thank you for your time mark I do greatly appreciate it. Hope this helps
 

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It doesn't. 99% of that is gibberish.

Does it have any codes now?
 

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Discussion Starter · #13 ·
After I cleared them last night and took the truck for a drive to try and get new codes, nothing came up. I figured I would get something since it felt like the computer put the trans in what I’m hoping was limp mode. I will say that the OD light was not flashing afterwards tho. I will hook the scanner back up again tonight. This might take a more lengthy answer than what you want to give me but if you could. What main sensors does the pcm use to control shift strategies. I know gas pedal position but what others? Im wondering because if I get extra time I would like to look at the wiring that goes to them.
 

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I will probably miss some of them, but the shift strategy uses pedal position and vehicle speed as the main inputs as to when it shifts. It also modifies the shift schedules with input from engine temp, trans temp, engine speed, transmission range sensor input.
 

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Discussion Starter · #15 ·
Ok, thank you Mark. I do know my engine temp gauge isn’t working but I’m going to assume that the pcm uses a different sensor than the gauge. I do enjoy making old things work again but I had no idea the electrical gremlins that the older E4od can come with. Well for me right now this is a good learning lesson.
 

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PCM will use Engine Oil Temperature (EOT) sensor for monitoring temperature. Cheers!
 

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Discussion Starter · #19 ·
I feel this has absolutely nothing to do with this but when I did my line pressure test. Someone before had put a temp sensor in the test port. When I did my testing I never had an issue with the trans doing this to me. The sensor end was a little long, probably 3/4 to an inch long past the threaded part. Is it possible there is a port inside that this sensor is covering? I’m sure this is nothing but I’m trying.
 

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You're right, that is nothing. Even if that port were totally blocked the only thing it would affect would be the reading on an external gauge.
 
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