Sport trac 5.0 plans

[chad551]

ST's are spring under the axle. That is why the SOA (Spring Over Axle) conversion is so popular.



Chad

 

[aeaglenfitch]

oh yeah huh i could have just looked at the pictures.

now im pretty sure the answer is yes but my intake and chip from my 98 mounty should swap over to an 01-05 4.0 st right?

 

[CDW6212R]

If you mean a PCM chip I'd ask the tuners, the PCM calibration code may keep you from a direct swap.

 

[rwenzing]

The 2004 Sport Trac got a new electronic cluster with its own onboard microprocessor. Along with that change came a lot of rewiring. IMO, that alone makes the 2001~2003 ST a better candidate for an Ex 5.0 swap.

As mentioned above, a 99~2001 Explorer 5.0 would be the best choice for a ST because they are both mechanical returnless fuel.

However there are still some electrical issues that would need to be addressed, even for a 2001~2003 ST using a 99~2001 Ex 5.0.



Tachometer:
One wire pin needs to be relocated behind the cluster to make the tachometer read the V8 correctly. Easy.



Passive Anti-Theft System (SecuriLock):
98~2001 Explorers are type B PATS which uses a standalone PATS Module. All 2001~2003 STs manufactured after 7/24/00 have type E PATS which has the PATS Module functions integrated into the PCM. (If you can find a rare early 2001MY ST manufactured before that date, it should have the same B PATS as the 5.0L Ex.)

For the 2001.5~2003 Sport Tracs that came with type E PATS: if you just swap in the 98+ Explorer 5.0 and its PCM/calibration, PATS will no longer work and the engine will not start. To correct this, you have 2 choices:

• Find a way to bypass/disable PATS; or
• Install and wire the PATS Module and PATS transceiver from the 5.0 Ex into the ST. You would also need #1 transponder keys to match the type B PATS components.

Vehicle Speed Sensor:
In the case of 98+ 5.0 Explorers, the raw speedometer signal originates at the rear axle ABS sensor and is corrected and output as a square wave from the 4WABS Module. It is sent from there to the PCM, speedometer, speed control, etc. [Note: Early 2001MY ST (probably before 7/24/00) use the same system as the 98~2001 5.0 Explorer. That should make the speedometer work without further modification]

By contrast, the 2001.5 ~2003 Sport Trac takes the raw signal from the OSS sensor on the transmission and the PCM outputs the corrected square wave to be used by the speedometer, speed control, etc.

The 4WABS Module in the 2001.5~2003 Sport Trac cannot make the speed correction like the 4WABS Module in the 5.0 Explorer can. So, simply swapping the Ex PCM into the Sport Trac will leave the vehicle without a speedometer, odometer, speed control and anything else that requires the corrected square wave.

There are a couple of ways around this:

• Swap in the 4WABS Module and G-force sensor from the 5.0L Ex and rewire to support it. The problem with this method is that the 4WABS in the ST has Electronic Brake Force Distribution (front/rear proportioning done by comparing slip ratios in software) but the 5.0 Ex has a mechanical proportioning valve. Using the 5.0L Ex 4WABS Module in the Sport Trac would leave it with no front/rear brake proportioning whatsoever - not good.
  
• Use the Ex PCM and the original ST 4WABS Module and then add a dedicated module just for the speed conversion. Properly wired, a GEM from a 2001 2.5L Ranger will work for this.

 

[CDW6212R]

"...Use the Ex PCM and the original ST 4WABS Module and then add a dedicated module just for the speed conversion. Properly wired, a GEM from a 2001 2.5L Ranger will work for this."

Interesting, Bob do you mean to use the 2001 2.5 Ranger GEM module as the speed conversion device?

 

[rwenzing]

"...Use the Ex PCM and the original ST 4WABS Module and then add a dedicated module just for the speed conversion. Properly wired, a GEM from a 2001 2.5L Ranger will work for this."

Interesting, Bob do you mean to use the 2001 2.5 Ranger GEM module as the speed conversion device?

Exactly. Some Rangers from 1998~2001.5 did the VSS correction/conversion in the GEM. My Ranger still has its original GEM for its timing functions but uses the added 2001 2.5 GEM just for the VSS conversion.

It is possible that the GEM from a 98~2000 RABS Ranger might also work. I chose the 2001 2.5 because, to the best of my knowledge, it was the only time on any RBV that the factory had the 4WABS and the GEM connected to the same input from the rear axle ABS sensor.

Before getting around to adding the 01 Ranger GEM, I had also tried two 4WABS Modules - the original for the Ranger's 4WABS plus another from the 5.0 Explorer just for the speed conversion. That didn't work - apparently the rear axle ABS sensor could not supply two 4WABS Modules at once.

I put a lot of time into this because I didn't want to give up the EBFD proportioning on my Ranger when I did the 5.0L conversion.

 

[aeaglenfitch]

thanks for taking the time to write all that out, i'll deffinatly use it when i do the swap.

 

[JohnnyO]

Wow. Somebody save all that info.

 

[danlong]

I'm the one who was planning on the 5.0 swap and 4.0 swap back. Unfortunately I haven't gotten it done due to time and too many other projects still going on. I haven't completely given up on it yet, but I have put the donor truck for sale because I don't know when I can get to it. We'll see what happens with it.

On a side note, regarding the VSS in the Sport Trac.... are you sure about the location and function of the sensor? Maybe its different in the later Tracs with the newer cluster? The reason I ask is there's a member on MySportTrac.com who regeared his rear end and found that his MPH to RPM relation has changed. He's now showing higher RPM's at the same speed as before, but he hasn't reprogrammed for the gears. If the sensor is before the rear end the truck doesn't know that his gearing has changed and should be showing MPH based on RPM of the driveshaft. Any ideas?

 

[chad551]

Bob,
Can I bring my 2002 ST and my donor 5.0 EX to your house and do the swap?????

You have a wealth of knowledge!!!!

Chad

 

[rwenzing]

On a side note, regarding the VSS in the Sport Trac.... are you sure about the location and function of the sensor? Maybe its different in the later Tracs with the newer cluster? The reason I ask is there's a member on MySportTrac.com who regeared his rear end and found that his MPH to RPM relation has changed. He's now showing higher RPM's at the same speed as before, but he hasn't reprogrammed for the gears. If the sensor is before the rear end the truck doesn't know that his gearing has changed and should be showing MPH based on RPM of the driveshaft. Any ideas?

As far as I can determine, Sport Tracs from 2002~2005 had the sensor at the transmission (OSS) regardless of whether the year called for a cluster with a mechanical or a digital odometer.

The problem with the 2001 Trac is that is was introduced very early in 2000 calender year as a 2001. A bunch of electrical stuff and the entire PATS configuration changed around 8/2000 even though the Tracs before and after that date were both called 2001's. So, I guess it's possible that an early 2001 could have a different VSS arangement from a late 2001. I can't confirm one way or the other because I don't own the wiring schematic book for the 2001 Trac.

 

[MountaineerGreen]

On a side note, regarding the VSS in the Sport Trac.... are you sure about the location and function of the sensor? Maybe its different in the later Tracs with the newer cluster? The reason I ask is there's a member on MySportTrac.com who regeared his rear end and found that his MPH to RPM relation has changed. He's now showing higher RPM's at the same speed as before, but he hasn't reprogrammed for the gears. If the sensor is before the rear end the truck doesn't know that his gearing has changed and should be showing MPH based on RPM of the driveshaft. Any ideas?

MPH will not change with regaring. When I put my 4.10's in, I expected my speedo to change, but it did not. Reason being, vehicle speed is taken from the tone ring on the ring gear of the rear end. The ring gear is a 1:1 ratio regardless of the axle ratio. Yes, the driveshaft is making more or less turns, depending on how the gears were changed, but the final drive is still 1:1. ExplorerDMB explains all this very well in a thread somewhere on here.

 

[danlong]

I have the 2001 Wiring Diagram book, but I can't really tell what's going on with the VSS. There is a Rear Axle Speed sensor, an Output Shaft Speed sensor, an Intermediate Shaft Speed sensor and several references in "pin-out" charts to a Vehicle Speed Sensor. If you can tell me what to look for exactly, I might be able to figure it out. I'm pretty good with wiring, but it helps immensely when I know the basics of how something works.

 

[danlong]

MountaineerGreen, read reply #24 by Bob. If the VSS is at the transmission as he indicates that the Sport Trac is, then it will change.

 

[rwenzing]

I have the 2001 Wiring Diagram book, but I can't really tell what's going on with the VSS. There is a Rear Axle Speed sensor, an Output Shaft Speed sensor, an Intermediate Shaft Speed sensor and several references in "pin-out" charts to a Vehicle Speed Sensor. If you can tell me what to look for exactly, I might be able to figure it out. I'm pretty good with wiring, but it helps immensely when I know the basics of how something works.

Take a look at the section for the Vehicle Speed Control (cruise). In most Ford wiring books this is section 31 but the 2001 books are screwy and it may be something like 310-03-00 instead.

In the diagram, it should give the source of the signal as either the rear axle (ABS) sensor or the OSS sensor on the transmission. Two wires go from the sensor to a module for correction, either the PCM or the GEM or the 4WABS Module.

The Ranger line used two different systems concurrently for a while during the first part of the 2001MY. I'd be interested to know which sensor and module the 2001 Trac used and if there were possibly two different VSS systems, early and late.

 

[MountaineerGreen]

That's very strange, I didn't realize ST's were different from Explorers- even the V6's 98-01 used the ABS tone ring.

 

[rwenzing]

That's very strange, I didn't realize ST's were different from Explorers- even the V6's 98-01 used the ABS tone ring.

It 's confusing because the speedometer setup has changed so many times. I believe the transitions went like this:

• Ranger Based Vehicles through 94: speedometer cable to mechanical speedo head.
  
• 95~97 RBV: signal generator at transmission or t-case to electric speedometer/odometer.
• 98~2000 RBV: rear axle (ABS) sensor to GEM or 4WABS Module to electric speedo/odo.
• 2001+: Most RBV's changed to the transmission's OSS sensor for the speed signal source and made the tire/axle correction in the PCM. 2001 4-door Explorer retained the rear axle sensor as the VSS until the major Gen3 change at 2002.

 

[MountaineerGreen]

Those crazy engineers at Ford

 

[danlong]

It's pretty confusing, but circuit 679 (GY/BK) runs from the ABS contol module to the PCM, and from the PCM to the Speed Control Servo. The wire from the ABS module to the PCM is shown as "early production" and it also shows a "late production" wire from the same pin that says "not used". This indicates to me that speed is determined from the RABS sensor on the Early Production 2001's.

On the page showing the Speedo Control Servo, there is a thin dashed box on the right side of the wire coming from the PCM to the Servo that says "Late Production" and another smaller dashed box just to the left with "68" in it. What is this representing?

 

[rwenzing]

It's pretty confusing, but circuit 679 (GY/BK) runs from the ABS contol module to the PCM, and from the PCM to the Speed Control Servo. The wire from the ABS module to the PCM is shown as "early production" and it also shows a "late production" wire from the same pin that says "not used". This indicates to me that speed is determined from the RABS sensor on the Early Production 2001's. On the page showing the Speedo Control Servo, there is a thin dashed box on the right side of the wire coming from the PCM to the Servo that says "Late Production" and another smaller dashed box just to the left with "68" in it. What is this representing?

This is what I was guessing at before in my other post. Based on what you're seeing in the 2001 Wiring Manual, it appears to confirm that:

The early 2001MY ST 4WABS Module takes the raw speed pulse from the ABS sensor on the rear diff, adjusts it internally for tire size, then outputs the corrected VSS on the GY/BK to the speedometer, PCM, speed control, etc. In this system, the corrected VSS is an input to the PCM, probably on pin 58;

The later 2001MY ST PCM takes the raw signal from the OSS sensor on the transmission, corrects it for tire size and axle ratio internally, then outputs the corrected VSS on the GY/BK. In this system, the PCM is the conversion module and the corrected VSS is an output from the PCM to the speedometer, speed control etc. The GY/BK is now on pin 68 of the PCM connector.

My guess is that the change was made around 8/2000 when a lot of other revisions were made to the 2001MY Sport Trac electrical system.