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I have a 02 Ford e150 that my brother has been driving ever since I got it running. But now I seem to be having trans issues. The trans grinds or like a howling noise when in 1st and a little bit in reverse. It’s only there in those gears. Other then that the trans shifts perfectly fine and the truck drives perfectly fine.
I pulled the codes and got p0743 and p1746 which from what I understand is torque converter elec circuit and some sort of short circuit code. I also noticed the OD light blinking on the shift lever.
I’ve concluded that this is most likely a mechanical issue in the trans and it’s not worth going in there because even if I fix the electrical it’s not going to stop this grinding. (I think)
I’m just looking for some sort of confirmation from someone more knowledgeable then me. I have no problem changing out the trans that is easy for me. I’ve never been inside one though.
I’ve linked a video of the noise too. Thank you for your time!
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I had my coworker ride in it with me and the trans started acting up worse. When trying to start from a stop it was in a higher gear and would stall. He was saying the converter was staying locked?
First, check fuses, both in the cab and under the hood. Make sure there aren’t any blown. Second, check the trans fluid color, smell, and for glittery bits under bright light. I usually wipe the dipstick on white paper and look at it under sunlight. If the fluid is a good color, doesn’t smell burnt, and no glittery bits, then the trans is probably fine. The codes pertain to the torque converter clutch solenoid. That’s why I asked you to check fuses first. If the fuses are ok, then check the wiring to the TCC solenoid to make sure it is intact. Check the resistance of the TCC solenoid coil. It should be somewhere between 0.2 and 0.6 ohms. If it is open circuit or more then 1 ohm, it needs to be replaced. If you place the shifter in low and drive under 10 mph, can you still hear the noise? Another cause can be a cracked flex plate, but I don’t think that would cause the symptom to disappear after shifting.
Sorry I forgot to include that but the trans fluid is clean. No burnt at all I will check it again.
The noise is there in low (if you drop it all the way to 1) that’s it. Only first gear. Noise is gone in the other gears. But would the torque converter solineoid cause a noise in only one gear?
I’m just thinking that because I don’t wanna spend time chasing this solenoid if the trans has mechanical issues.
The TCC solenoid shouldn’t cause any noise in any particular gear, but can be responsible for stalling when decelerating for a stop. The TCC is just one of the components you got a code for. Together, the codes paint a different picture and do not necessarily point to the TCC as the problem. I understand your concern, and you are correct, because a crack in a planetary gear housing or chipped teeth in a planetary set can cause this noise in just 1st and reverse where there is no noise in other gears. Only a full tear-down will reveal that, though, as there is no other way to inspect or determine the condition of a planetary set. But, it is much easier to troubleshoot an electrical circuit than do a trans tear-down. So, yes, check out the electrics first. It makes no sense to go through the gearbox mechanically when the cause of the problem is electrical (a fuse or corrosion in a connector). The code P0743 indicates TCC electrical malfunction. The P1746 indicates EPC circuit open. The open is the key word. This means something that should have power doesn’t. If it was shorted, you’d have code P1747 instead. Look at the wiring diagram below. You will see that the TCC and EPC share fuse #24. You will also see they share a power feed (splice S136 [S138?] ) at the back up lamp wiring harness. These would be two key places to look first.
thank you for the diagram, i was looking at alldata and i checked the resistance on the TCC solenoid and it measured 18 ohms initially then 16 ohms, Alldata is saying 10-16. i checked every fuse in both boxes, but i will double check fuse 24 when i get back to it. would the easiest way to be check the power on the trans connector i was probing for the solenoid?
what does a “splice” mean? is that another connector? or actually part of the harness?
Yes, you can check at the transmission connector. According to the diagram I posted, pins #1 and #12 and should read ~12v with key on engine off and trans in park. According to my information, the resistance for your TCC solenoid should be between 10 and 20 ohms, and is pulse-width modulated (PWM) rather than the standard on/off type. The EPC solenoid is also PWM and similar resistance. This means the ground for these is supplied by the computer, but because they are PWM, they are modulated and therefore you cannot just apply a ground directly to them as the coils are not designed to take a constant ground like that and could burn out. The shift solenoids are conventional on/off (not PWM). All of them are located inside the transmission pan. By the way, there is a TSB (technical service bulletin) that mentions that the solenoid connectors inside the pan can work loose (not be fully seated) and result in your symptoms. If your fuse and voltage test checks out, that might be the next place to go.
A splice is not a connector, but usually a soldered or crimped wire connection, or wire terminals connected to a stud/nut or other hardware type of connection. They are very commonly seen on ground and power distribution wires. If they are inline soldered or crimped, they can usually be seen as a lump wrapped up in tape inline with the wiring as part of the wire loom.
no wonder your diagram is so different then mine! its the 4r70w not the 4r100.
im checking power at connector c1274, i have power on pin 1 (red wire) at key on, so i know everything before that and fuse is good.
looks like i will be pulling the pan soon, hopefully tomorrow, do i really need a scan tool that i can activate the solenoid? do i need to activate the solenoid and check the line pressure?
im betting there is going to be a decent amount of metal in the pan and i wont have to go that far. lol
Ok, no problem. The electronics are still very similar though.
You may need only to change the solenoid pack.
Here’s the 70W:
Well pulled the pan off today, looks like i dont need to go any further!
looking at getting a reman or maybe one from a junkyard.
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