4r70w Swap Speedo wiring

[Wagonbacker9]

" The 5r55 wants to see a 24x signal at the oss. "

Okay so the old 5r trans used to have dual OSS sensors. The 4r70w has a single OSS sensor.
Your goal here is to make the engines computer happy by replicating the missing oss signal correct?
And by doing so we are hoping the speedometer/odo start working
CORRECT?

Your 4r70w uses the older style 6x version OSS, the single existing oss

Why not take the existing 6x oss signal and multiply it by 4 to achieve the 24x oss signal the ECM is expecting?

Is my thinking correct here?

Forget about your VSS and tire size, etc etc.....you are trying to replicate a second OSS, right?
You are not trying to do all the smoothing for the dash....you are simply trying to make your ECM happy (Think it still has a 5r55 trans)

I think they call it an intermediate and output sensor, but short answer: yes.

And correct, I’m simply trying to get speed signal to the pcm to supply the dash (and ideally cruise). I would also functionally accept bypassing the ECM and suppling a signal directly to the cluster, if I had a way to achieve that.

For input to the Dakota box I believe functionally I could use:
1) the 4r70w oss (6x, ~16kppm)
2) the rear differential vss (8kppm)
3) the tail housing vss (I haven’t even looked up what this signal is)

In theory at least, any or all of these will supply a usable (re-configurable) signal. My preference is to use the tail housing vss ONLY because then I’m not interfering with the currently fully operational abs and trans control systems. As an added bonus Of using that sensor, I’m guaranteed not to have ground offset or interference because I am grounding that sensor via the Dakota box (I ran a wire for this purpose), not the stock ECM or abs.

Currently my challenge is entirely on the output side of the Dakota box (getting an output to show up on the dash), so there’s really no point in belaboring the input side pros/cons until I have an output that works. The Dakota box has an option to provide a “fake” output (can trigger it via Bluetooth), so I don’t even need to troubleshoot the input side (r move the truck for that matter) to test the output side at all.

 

[410Fortune]

Allright.............

I propose we forget about bypassing the pcm and instead send it a signal so it thinks you are still 5r55?
The result of this should be a working dash

We should make sure your ISS, TSS and OSS are hooked up to not only the baumman but also stock pcm
Then add in the missing second OSS using the dakota.
Make sense?


If this does not work then we can bypass the pcm and send the 8000 ppm to the cluster directly IF that is needed.

The rear diff VSS does NOT send a 8000ppm signal
the rear diff VSS sends more like 77000 ppm:
the tire revolutions x teeth on speed sensor tone ring gear = ppm
For your tires 697 RPM and a 8.8 tone ring has 108 teeth = 75,276 ppm
IF your 03 still has a 108 tooth ring gear on the IRS rear diff tone ring

the dakota is what takes the 75276 ppm and converts it to 8000ppm the truck can understand

 

[Wagonbacker9]

We should make sure your ISS, TSS and OSS are hooked up to not only the baumman but also stock pcm
Then add in the missing second OSS using the dakota.
Make sense?

I don’t think that’s possible for 2 reasons:
1) I only have one sensor on the trans (ignoring the vss on the tail housing)
2) the sensor I have is magnetic, not hall effect

If this does not work then we can bypass the pcm and send the 8000 ppm to the cluster directly IF that is needed.

I agree that would be “plan B”. It is a less than desirable solution, however it sounds like in theory, I may be able to hook the vss in the tailhousing straight to the dash and it would work. Maybe. Kinda.

As of right now my plan is to hook the Dakota output to the OSS wire AT THE PCM (today it’s wired down at the frame rail near the tail housing). Use the L/H configuration with a ~.5 calibration, and also shoot the tuner an email and ask if maybe something is shut off in the PCM that I need for this to work.

 

[410Fortune]

Ah I see your early 4r70 does not have a ISS or TSS, dang!!


how many teeth are on the oss driveshaft /tone ring?

I believe what your math might need a re visit. The tire rotates 697 revs per mile
The driveshaft spins 3.73 times per revolution correct?
So the rear driveshaft is spinning 697 x 3.73 = 2600 revolutions per mile at the driveshaft
But How many teeth are on the shaft spinning the 4r70w oss sensor? 6ea?

 

[Wagonbacker9]

Ah I see your early 4r70 does not have a ISS or TSS, dang!!


how many teeth are on the oss driveshaft /tone ring?

I believe what your math might need a re visit. The tire rotates 697 revs per mile
The driveshaft spins 3.73 times per revolution correct?
So the rear driveshaft is spinning 697 x 3.73 = 2600 revolutions per mile at the driveshaft
But How many teeth are on the shaft spinning the 4r70w oss sensor? 6ea?

Irrelevant, as the oss is not being used for anything but the tcm.

 

[Pontisteve]

Hey guys, I’ve been on this forum collecting info for months, finally made an account because I can’t figure out this problem for the life of me.
I have a 2003 explorer, mod list is WAY too long to get into, I’ll make another post for that. The truck has an early version 4r70w swapped into it with a baumann controller. Works great, but nothing is connecting the trans to the ECM so I get no speedo and no odo.
I bought a Dakota sgi100-bt and have it hooked up to the vss on the tail housing, but cannot for the life of me get the speedo to give me any kind of life. I tried hooking into the stock OSS and stock vss wires at the PCM, and still get nothing.

Any suggestions?

In a 2003 Explorer V8, the Output Shaft Speed Sensor (OSS) sends a raw signal to the PCM. The PCM is in charge of processing this raw input, and turning it into a MPH value. Then the PCM shares this MPH with other modules as needed over the network. This sensor is likely just in charge of the MPH used to determine the trans shift points.

The trans also has an intermediate shaft sensor and a turbine shaft sensor, both of which report to the PCM.

If your vehicle does not have IVD, there is a rear axle speed sensor that feeds the ABS module a raw signal. The ABS module could then share that signal over the network with the PCM (Like the 99-01 Rangers do).

If your vehicle does have IVD, then there are two rear wheel speed sensors, left and right, that feed the ABS module with wheel speed data. The ABS module could then share that signal over the network with the PCM (like the 99-01 Rangers do).

So as you can see, there are 3 possible sources of raw speed signal for this vehicle. OSS, Rear Axle Sensor, and bothRear Wheel Speed Sensors. Service information did not help reveal the source, but my experience tells me that the OSS generally runs the trans, and the VSS generally runs the speedo. In this case, if that is true, it's either the rear axle sensor (if equipped), or both rear wheel speed sensors that act as the raw speed signal, and the 4WABS module is in charge or processing that signal and sharing it with the PCM, which then shares it with the instrument cluster.

The raw speed signal is factored in along with the gear ratio and tire size, which are both programmed into the ABS module. The calibration likely stores the number of teeth on the OSS. This number should match in your new trans. If your new trans has a different number of teeth on it's OSS reluctor wheel than the original trans, then you should reprogram the PCM, updating it with the number of teeth from the new OSS reluctor wheel. Also, the auto trans function should be turned off in the calibration, so the PCM doesn't throw a ton of Trans codes.

One other thing to consider is that often times, many modules get a copy of the MPH signal. For example, the radio probably increase in volume as it sees that you are going faster, to compensate for wind noise. You never know what needs to know the vehicle speed. This MPH reading is shared over the SCP network with all the other modules.

And most Ford speed sensors are the same type of variable reluctor sensor. They are all AC sinewaves. Therefore, even if they are not reading the correct value directly, all of them should produce some sort of speed signal.

 

[410Fortune]

Good info there
What is IVD?

In this swap he installed a earlier 4r70w which only has a single OSS, no ISS or turbine sensor

So the PCM will need a tune will it not if he wants to rid of the transmission codes?

 

[Wagonbacker9]

In a 2003 Explorer V8, the Output Shaft Speed Sensor (OSS) sends a raw signal to the PCM. The PCM is in charge of processing this raw input, and turning it into a MPH value. Then the PCM shares this MPH with other modules as needed over the network. This sensor is likely just in charge of the MPH used to determine the trans shift points.

The trans also has an intermediate shaft sensor and a turbine shaft sensor, both of which report to the PCM.

If your vehicle does not have IVD, there is a rear axle speed sensor that feeds the ABS module a raw signal. The ABS module could then share that signal over the network with the PCM (Like the 99-01 Rangers do).

If your vehicle does have IVD, then there are two rear wheel speed sensors, left and right, that feed the ABS module with wheel speed data. The ABS module could then share that signal over the network with the PCM (like the 99-01 Rangers do).

So as you can see, there are 3 possible sources of raw speed signal for this vehicle. OSS, Rear Axle Sensor, and bothRear Wheel Speed Sensors. Service information did not help reveal the source, but my experience tells me that the OSS generally runs the trans, and the VSS generally runs the speedo. In this case, if that is true, it's either the rear axle sensor (if equipped), or both rear wheel speed sensors that act as the raw speed signal, and the 4WABS module is in charge or processing that signal and sharing it with the PCM, which then shares it with the instrument cluster.

The raw speed signal is factored in along with the gear ratio and tire size, which are both programmed into the ABS module. The calibration likely stores the number of teeth on the OSS. This number should match in your new trans. If your new trans has a different number of teeth on it's OSS reluctor wheel than the original trans, then you should reprogram the PCM, updating it with the number of teeth from the new OSS reluctor wheel. Also, the auto trans function should be turned off in the calibration, so the PCM doesn't throw a ton of Trans codes.

One other thing to consider is that often times, many modules get a copy of the MPH signal. For example, the radio probably increase in volume as it sees that you are going faster, to compensate for wind noise. You never know what needs to know the vehicle speed. This MPH reading is shared over the SCP network with all the other modules.

And most Ford speed sensors are the same type of variable reluctor sensor. They are all AC sinewaves. Therefore, even if they are not reading the correct value directly, all of them should produce some sort of speed signal.

I appreciate the VERY technically thorough and, unfortunately unhelpful response. Logging the PCM, both OSS which I am force feeding data to from the dakota box, and VSS (which in theory was untouched from factory) read nothing.

At this point I need to figure out a way to feed a signal, either off the VSS in the tailhousing (assuming it works), or off of the 4r70w oss (which is the only speed signal in the truck I KNOW works directly to the Cluster, or I need to just accept defeat and install a GPS speedo.

 

[Wagonbacker9]

Good info there
What is IVD?

In this swap he installed a earlier 4r70w which only has a single OSS, no ISS or turbine sensor

So the PCM will need a tune will it not if he wants to rid of the transmission codes?

Last I looked the only trouble code I have is related to fuel pressure (its got an entirely custom return system), and frankly I haven't cared enough to ask the tuner to shut it off yet. So I think its safe to assume hes already tuned all that stuff out.
I did ask if there was any tune setting that would be "blocking" the OSS signal and he didn't believe there was.

I'd assume IVD is another name for the RSD or whatever they called traction control in this model... which I am not equipped with.

 

[CDW6212R]

I appreciate the VERY technically thorough and, unfortunately unhelpful response. Looking the PCM, both OSS which I am force feeding data to from the dakota box, and VSS (which in theory was untouched from factory) read nothing.

At this point I need to figure out a way to feed a signal, either off the VSS in the tailhousing (assuming it works), or off of the 4r70w oss (which is the only speed signal in the truck I KNOW works directly to the Cluster, or I need to just accept defeat and install a GPS speedo.

What are you using for the VSS you just mentioned? Is that the ABS wires from the rear diff, or is it the VSS from the 4R tail housing? Those pre-98 transmissions would have a speed sensor there which generates the VSS, made for 1997 models or older. The one from the rear would be a slightly different signal. The one from the trans should be just what the older PCM wants if it's working. The later vehicles conditioned that rear ABS signal to make it a VSS like the old type sensors. That's the way it has been explained where I've read of it.

The speed sensors on the side of the transmissions shouldn't help with a speedometer, those are not measuring output shaft speed.

 

[Wagonbacker9]

What are you using for the VSS you just mentioned? Is that the ABS wires from the rear diff, or is it the VSS from the 4R tail housing? Those pre-98 transmissions would have a speed sensor there which generates the VSS, made for 1997 models or older. The one from the rear would be a slightly different signal. The one from the trans should be just what the older PCM wants if it's working. The later vehicles conditioned that rear ABS signal to make it a VSS like the old type sensors. That's the way it has been explained where I've read of it.

The speed sensors on the side of the transmissions shouldn't help with a speedometer, those are not measuring output shaft speed.

Currently I'm wired to the tailhousing VSS as my speed input. My presumption is that the VSS signal to the ABS and ECM come from the rear diff, which does beg the question why it sees no signal, but that is of no concern to me at the moment. (No ABS light on, and honestly, if the ABS ever goes off on this thing I have bigger problems anyway)

I've read the same thing, that the rear diff VSS is what fed later speedos, but with limited info on the explorer, I don't know when that conversion was made. The builder of dora the explorer indicated that he is feeding OSS from his Quick6 controller to get the ECM to operate (I believe he is a 2004 model year, lets assume 2005 is electronically the same), so best guess would be that ford didn't do that on this platform until at LEAST 2006. This is of course conjecture based on 3rd hand information so consider it accordingly.

and yes, the ISS/TSS are useless for vehicle speed, which makes my problem only slightly less complicated, seeing as I don't have either.

The most frustrating part is my Baumann controller will literally show me a MPH calculation on my laptop (based on the OSS signal, gear ratio, tire size, etc), so the data is IN THE TRUCK... but theres no way to get it from the baumann to the ECM or speedo.