Swap, now E4OD won't shift
Thread Starter
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Trailering
Joined: May 2024
Posts: 22
Likes: 5
It dropped to about 1500rpm. That tells me that it was in overdrive at that point. I would then let off the throttle ever so slightly so I wouldn't keep accelerating and it would downshift back to what seemed like direct.
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,722
Likes: 2,647
From: SE Florida
My guess as to what's happening is that when you roll into the throttle the torque converter is locking. When you back off a little it is unlocking. If that is what is happening, I think the TP sensor is not adjusted properly. It would be reading a lower voltage that normal if that is what's happening.
Thread Starter
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Trailering
Joined: May 2024
Posts: 22
Likes: 5
I will double check the TPS, but I don't see that being the case. It all worked fine before the swap and I didn't touch the TPS, but I will verify its good.
I did hook up the sensor for the brake master cylinder switch that I think unlocks the torque converter when you step on the brake? But its just hanging out under the hood because the vans master cylinder doesn't have a port for it.
I also hooked up the OD cancel button. It works as it should with no flashing or anything.
While I am in direct (OD cancel light on) the torque converter does the same thing. Unlocked a majority of the time until I roll the throttle on, then it locks.
I did hook up the sensor for the brake master cylinder switch that I think unlocks the torque converter when you step on the brake? But its just hanging out under the hood because the vans master cylinder doesn't have a port for it.
I also hooked up the OD cancel button. It works as it should with no flashing or anything.
While I am in direct (OD cancel light on) the torque converter does the same thing. Unlocked a majority of the time until I roll the throttle on, then it locks.
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
The Brake Pressure Switch on the master cylinder is a redundant circuit to shut off the speed control.
The Brake On/Off switch at the brake pedal tells the computer the brake is applied. That circuit uses a ground path via the Brake lamp bulbs.
The Brake On/Off switch at the brake pedal tells the computer the brake is applied. That circuit uses a ground path via the Brake lamp bulbs.
Thread Starter
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Trailering
Joined: May 2024
Posts: 22
Likes: 5
Ok. Noted. Thank you.
So let me go a bit more into detail. When I went to look at the truck, the brake pedal stuck slightly, so slightly that the brakes wouldn't be applied, but the brake lights would stay on.
While test driving it, I noticed when the pedal was stuck, it would exhibit the same characteristics as it is right now (I have since learned that it's the torque converter being unlocked). When I put my foot behind the pedal to bring it all the way up, the torque converter would immediately lock.
On these trucks, is it normal for the torque converter to unlock as soon as the brakes are applied?
So let me go a bit more into detail. When I went to look at the truck, the brake pedal stuck slightly, so slightly that the brakes wouldn't be applied, but the brake lights would stay on.
While test driving it, I noticed when the pedal was stuck, it would exhibit the same characteristics as it is right now (I have since learned that it's the torque converter being unlocked). When I put my foot behind the pedal to bring it all the way up, the torque converter would immediately lock.
On these trucks, is it normal for the torque converter to unlock as soon as the brakes are applied?
Frmr Ford Trans Engr
Joined: Aug 1999
Posts: 24,722
Likes: 2,647
From: SE Florida
When the PCM thinks the brakes are on as indicated by the BOO (brake on off) circuit it will unlock the converter when the accelerator pedal is less than 10% depressed. Once the pedal is over 10% the BOO input is ignored and the converter can lock.
This seems to match what you are describing.
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Thread Starter
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Trailering
Joined: May 2024
Posts: 22
Likes: 5
Now this makes sense. I know what's happening.
When the PCM thinks the brakes are on as indicated by the BOO (brake on off) circuit it will unlock the converter when the accelerator pedal is less than 10% depressed. Once the pedal is over 10% the BOO input is ignored and the converter can lock.
This seems to match what you are describing.
When the PCM thinks the brakes are on as indicated by the BOO (brake on off) circuit it will unlock the converter when the accelerator pedal is less than 10% depressed. Once the pedal is over 10% the BOO input is ignored and the converter can lock.
This seems to match what you are describing.
Before yesterday, I couldn't identify if it was shifting or unlocking/locking torque converter. Now things are making a pile of sense.
Thank you!
Thread Starter
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Trailering
Joined: May 2024
Posts: 22
Likes: 5
So I am looking into this this morning and things aren't making sense. From the factory, the BOO is designed to allow 12v through to pin 2 on the computer which tells the torque converter to unlock. Does that sound correct?
I don't have the switch hooked up, so pin 2 isn't seeing 12v from the BOO switch. However, with the engine running, pin 2 on the pcm is ready close to 10v. Is this correct? Should it read zero, or is the pcm putting the 10v out of pin 2?
I don't have the switch hooked up, so pin 2 isn't seeing 12v from the BOO switch. However, with the engine running, pin 2 on the pcm is ready close to 10v. Is this correct? Should it read zero, or is the pcm putting the 10v out of pin 2?
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
With an open circuit and dozens of others energized close by your DVM is most likely reading an induced voltage, i.e phantom. Yes it happens in DC circuits to. Chased my tail many times. A high impedance DVM will frequently lie to you in this scenario.
If you use an incandescent test lamp it will most likely not illuminate.
If a test lamp does illuminate, that implies the internal BOO circuit is most likely using a pull up resistor.
If you use an incandescent test lamp it will most likely not illuminate.
If a test lamp does illuminate, that implies the internal BOO circuit is most likely using a pull up resistor.
Thread Starter
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Trailering
Joined: May 2024
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Likes: 5
So the test light does not illuminate.
So this raises more questions than it answers. Being “no voltage” there, this means that the torque converter should lock up soon after shifting into third and forth if this circuit was the problem?
I tested the TPS and it is perfectly in spec.
Anything else I need to look at? Like I say, it has to be a wiring issue because it worked find before removing it from the truck.
So this raises more questions than it answers. Being “no voltage” there, this means that the torque converter should lock up soon after shifting into third and forth if this circuit was the problem?
I tested the TPS and it is perfectly in spec.
Anything else I need to look at? Like I say, it has to be a wiring issue because it worked find before removing it from the truck.