5R44E/5R55E ISS sensor on 2001, and up models.

I was reading this article about a new part that was added to the 5R44E/5R55E on 2001, and up models. Here is the link to that article: http://vmtp.co.uk/news-newford1.htm. The first question that came to my mind was if this part were added in addition, or instead of the internal sensor on the center support? It makes more sense to mount that sensor externally so that the entire transmission doesn't have to be dismantled just to replace a sensor.

Here is a reprint of that article:

VMTP NEWS
New Ford Transmission
5R44E & 5R55E
Courtesy of Bob Cherrnay
Technical Editor - Transmission Digest

Beginning with the start of production for 2001, Ford Motor Co. introduced a new-model transmission with the designation 5R44E, a five-speed transmission that replaces the previous-design 4R44E. This new 5R44E model, like the 5R55E transmission, has an added intermediate-shaft-speed (ISS) sensor.

Changes were also made to the PCM strategy, which now includes shift-adaptive pressure-control strategy. The 5R44E transmission is used in 2001 Rangers with 2.3L and 3.0L engines, and the new design 5R55E transmissions are in the Ranger, and Explorer models with 4.0L engines.

The 5R44E transmission was added to establish a commonality among transmission models, and the ISS sensor was necessary for the new PCM shift-adaptive pressure-control strategy. Some parts changes have been made to these new units. NONE of the parts listed are interchangeable with the previous design level parts.

Transmission Case - New transmission case casting, and machining to accommodate the added ISS sensor.
ISS sensor - This provides additional information for the PCM to determine various incremental pressure changes to minimize the difference between the actual, and ideal shift timing for shift-adaptive pressure control strategy.

Sun Shell - Now manufactured with windows, and used to trigger the added ISS sensor.

Powertrain Control Module - Operational changes that includes shift-adaptive electronic-pressure-control strategy.

Shift-Adaptive Electronic-Pressure-Control Strategy-
This strategy allows for improved control over the transmission shift events. On the basis of various input signals, the strategy calculates an actual shift time, and compares it with an ideal shift time. Once the vehicle is up to operating temperature, incremental pressure changes are made to minimize the difference between actual, and ideal shift times. Over time, the adaptive learning process will fully update keep-alive memory (KAM). The more varied the driving habits, the longer the update will take. However, the adaptive learning process will also be more complete. Adaptive pressure control strategy is capable of adapting upshifts, closed-throttle downshifts, and garage shifts. For diagnosis of the ISS sensor see below.

If for any reason the vehicle loses power to the KAM, the transmission will return to its present level. Reasons for this happening are a disconnected or fully discharged battery, PCM disconnected while the battery is still connected, or updated calibration programmed into the PCM.

5R44E/5R55E added diagnostics, and trouble code chart:

DTC Description Symptom Possible causes
P0791 ISS sensor failure
[signal loss]
Harsh 2-3 shifts
ISS sensor or wiring

P0794
ISS sensor signal
intermittent
Harsh 2-3 shifts
ISS sensor or wiring

P1636 SSx ISIG
communication error
None
Replace PCM

the only thing that looks different to me is that they took the tss from internal to be externall anyone else concur??????

I was thinking that too when I saw this picture, but my books don't have any information on the ISS sensor.

What set up do the N, S, and W versions have? Maybe they use this too?

This is the ideal use of a computer to make up for wear and aging. FORD needed more monitoring and inputs to make this work, so we got the ISS. There is still the TSS sensor.

Remember the computer CAN control the EPC and vary line pressure....this just allows it to do kind of a closed loop operation.

I can not speak for the W S or N, but CAN gurantee they upped the computer inputs.... for example, they monitor reverse pressure..... best as I know.

I am still learning about W S and N, sort of on the side... so take everything I say about them with a grain of salt at this point.

Aren't the TSS, and the ISS pretty much performing the same task measuring the speed of the internal shaft in the same area? Maybe the computer takes a comparison of both sensors, and provides a calculation.

Here is a link to something Glacier once said about the operation of the TSS sensor: http://www.explorerforum.com/forums/showpost.php?p=1399246&postcount=12

The Turbine Shaft Speed Sensor is mounted on the center support, and measures the speed of the input shaft. The PCM uses the input from this sensor to determine EPC pressure, and TCC control stategy. [Edit: I should add that the computer uses MULTIPLE inputs to determine these things, this is just one, but not the ONLY one!] The input shaft is turning at all times in all gears, and the TSS operates for all gears.

Click to expand...

The location of the ISS is after the forward drum, using the input shell... so that is a different part of the geartrain being monitored as compared to the TSS.

harsh 2nd to 3rd shifting

I realize this is an old post but to bring it back up. I have a 2001 Ford Explorer Sport and i am now experiencing harsh shifting from 2nd to 3rd gear, almost like its slipping, but will only do it once in a while, not all the time. The article mentions something about harsh shifting from 2nd to 3rd. I can't pull a code because for some reason i'm not getting any power to the plug to pull a code and i can't seem to figure out which fuse it would be. But if it is the ISS, would it make the o/d off light flash or not? And would it be like a slipping shift or would it be a hard shift into gear?

I was surfing the web for hours looking for this info. When I found it here I registered to say Thanks. I really needed to know what that connector was for. My trans swap project can proceed thanks to this bit of information.

Sorry to bring up an old thread but I just wanted to add some info in case someone is looking for the same info I was.

In regards to the extra 5r55e ISS sensor, I swapped a 2000 explorer sport (job 1) transmission into a 2001 explorer sport (job 2). There's info on other pages on how to tell the differences between the two. Anyhow, I took a risk with the installation since I was low on time and cash (blown trans and the tow truck driver had one avail for $400.00)

Relatively speaking, the swap was a breeze. The only thing missing was the ISS sensor on the replacement tranny so I taped up the leftover plug on the 2001 explorer sport transmission harness for later use.

The truck is running again but there are 2 important things to note: There is a slight slip in the transmission going from 2nd to 3rd gear, but all that happens is a slight increase in rpm until 3rd gear catches. Also, since the ISS sensor isn't communicating with the computer, the OD light blinks.

When replacing the transmission, I would still recommend counting the sensors beforehand and using the exact version of the 5r55e that you have. I don't drive much anyhow and with the money I saved I'm still gonna get the correct 5r55e job 2 transmission eventually--now I can find one with the lowest mileage possible.

MisterAlfonso said:

Sorry to bring up an old thread but I just wanted to add some info in case someone is looking for the same info I was.

In regards to the extra 5r55e ISS sensor, I swapped a 2000 explorer sport (job 1) transmission into a 2001 explorer sport (job 2). There's info on other pages on how to tell the differences between the two. Anyhow, I took a risk with the installation since I was low on time and cash (blown trans and the tow truck driver had one avail for $400.00)

Relatively speaking, the swap was a breeze. The only thing missing was the ISS sensor on the replacement tranny so I taped up the leftover plug on the 2001 explorer sport transmission harness for later use.

The truck is running again but there are 2 important things to note: There is a slight slip in the transmission going from 2nd to 3rd gear, but all that happens is a slight increase in rpm until 3rd gear catches. Also, since the ISS sensor isn't communicating with the computer, the OD light blinks.

When replacing the transmission, I would still recommend counting the sensors beforehand and using the exact version of the 5r55e that you have. I don't drive much anyhow and with the money I saved I'm still gonna get the correct 5r55e job 2 transmission eventually--now I can find one with the lowest mileage possible.

Click to expand...

I don't know if this will help but it might apply to you
"But what if the trans is out of the truck, on the floor or on the bench? In this case you can tell the difference by looking for the speed sensor. The 5R55E unit has a speed sensor located in the back, by the extension housing (figure 1). Neither the 4R44E or 4R55E have this sensor.


Figure 1

Speaking of sensors, the 5R55E originally had another speed sensor, mounted just behind the bellhousing. This sensor was intended to indicate how fast the coast clutch drum was spinning. This was supposed to help the computer control shift feel going into second and fifth gears (the coast clutch drum is held stationary by the band in second and fifth gears).

But the sensor ring kept falling off during durability tests at the factory, so the sensor was never incorporated into the computer's strategy. But the sensor was still installed, and the vehicle harness was connected to it. If you see one of these units, Ford recommends that you cut the sensor wires, connect them together, and then tuck them into the wiring loom. In 1999, the sensor and the hole in the case it fits into were eliminated."

Ok, so I'm not able to find any definite answers if it's ok to use this transmission without the ISS sensor hooked up?
It's going into a 96 that originally had the 4r55e. I just picked a replacement 5r55e up not realizing the ISS sensor was added. The second problem I found, after bolting it up to the engine, is that the starter pocket is smaller which I'm guessing will require a bellhousing swap? That's not a big deal to do but will it work?

There is no harm in using this transmission. Your vehicle doesn't have a plug for the sensor. You could also swap the bellhousing. The EPC & TCC solenoids are different so you might have to swap them. Check the DTRS as well since it might be different.