P0741

P0741 is the code for the transmission torque converter clutch locked off. I've been having a blinking OD OFF light for some time. I noticed it only does it when OD is engaged. If I drive it with the OD off, it doesn't occur. However, in OD I see the tach moves excessively when accelerating. So it's apparently not locked up. Friend has a transmission shop a mile from where I live. He told me to drive it til it starts blinking, then stop by and leave it running. Hooked up a scan tool and got the P0741 code. I told him it was likely a solenoid, which he said that wouldn't be the case. However, when I did a Google search on it, there are two solenoids that could be the problem and they are top of the list. So, I'll be taking it to his shop to have it fixed. Hopefully we can get this done soonest.

I just replaced the stupid plastic thermostat housing with a really nice metal one on Saturday. Was having a lot of little pissant leaks in that area. Made the engine compartment messy. Finally got that fixed, no more leaks. Was able to go back to a 16 pound radiator cap (I had a 10 pound one on there the last couple months), now on to the transmission.

Cars in my friends transmission shop today. Getting all new solenoids, and while he's in there he is going to install a shift kit for me. He says these particular transmissions were not one of Ford's greatest designs, and that they really do benefit from a good shift kit. So we'll see. Should have it back tomorrow.

Well, changing the solenoids didn't help. Started blinking within two miles of the transmission shop. Way faster than it has ever come on before. Now the shop guy says it's likely the torque converter itself. Think I'm just going to put a piece of black tape over the damn thing and keep driving it. It drives and shifts fine.

Odd. Very odd! Drove it to work today and it never blinked. On the way home, jumped on I-40 west bound and started cruising at 70 mph. The tach was locked steady at 2000, couple hundred rpms less than it has been as of late. Started playing the throttle, the tach barely moved. Evidently the lock up happened and it was holding steady. Will take it for a drive the next couple days, long cruise on the highway, see if it maintains. If so, then apparently it is either a delayed reaction to the repairs, or whatever was wrong fixed itself. I guess we'll just see, won't we. LOL!

There was mention in several articles on P0741, that wiring could be damaged. Could it be, that with the major coolant leak I had, coolant sprayed all around the engine bay, that something got wet that didn't like being wet. And since the coolant leak is fixed, it dried out and is doing what it's supposed to do?

Potomus Pete said:

What about the shift kit?

Click to expand...

Truthfully, can't tell it's there unless the pedal is on the floor. Otherwise, it feels the same. The shift from second to third was always kind of mushy. It's not now. But a valve body change, which us Lightning owners always do, would probably give it that kick most of us want.

Still having the problem, hard to track down what the cause is. Interestingly enough, it's only at around town speeds that it occurs. Drove it 60 miles at highway speeds yesterday, 60 to 85. never blinked once. My transmission friend says he thinks it very well could be the TPS. So, being an easy fix, I'll be doing that this weekend. Otherwise, it's really hard to know what is causing it. Obviously, it's locking up at high speeds. But at the 40 to 50 mph range, it locks up fine at first. But then, apparently, something is getting hot, and once that occurs, it starts having difficulties locking up. At first it manifests as a jerking when transitioning from level ground to uphill, as if it can't make up it's mind to lock up, or not. Soon after, the blinking OD OFF light.

Very frustrating. Fortunately, it doesn't cause any driving issues, except for an overactive tach when it won't lock up in OD.

When I drive it around town, I keep overdrive off and it doesn't occur. When I drive it on the highway, it doesn't occur. It only seems to occur if I let it go into OD at speeds below 60 mph. Weird I know. Been driving it like this since it started in May while throwing money at it bit-by-bit. Changed the fluid and filter recently, the fluid was bright red, didn't smell burned in the slightest. My friend who does transmissions seems to think it's the TPS. His son, who works with him, agrees. So I'll try that first before committing to a converter. He says he can do it, no problemo, if it's necessary.

When you search P0741, there are so many things that can cause it. Even the lowly coolant temperature sensor, if it's bad. Faulty wiring. Even the PCM itself can be the cause. Very bottom of the list is replacing the converter or the entire transmission.

The TPS is a rheostat. My friend says that if there are worn contacts in certain speed ranges that are driven a lot, like 40 to 50 mph, that are worn. The PCM won't get proper signals as to throttle position, and can cause weird stuff like jerking and the clutch not locking, or having difficulty doing so.

I'll get there eventually. Just trying all the easy-peasy, not removing the transmission stuff first. Another transmission specialist says the valve body needs to be vacuum tested, when I told him what's happening. So it's all over the place, what I need to do.

Oddly enough, the light isn't blinking any more. Had it in the garage with the negative terminal off for a few weeks due to weather. Hooked it back up and drove it around 100 miles both Saturday and Sunday. Clutch locked up in both 4th and OD with no troubles. I can see it on the tach when it's locked.