One Way to Save a First Gen: A4LD to 5R55E Swap (Completed)

Alrighty.....


Hooked up the crank sensor today finally, and about to go for a test drive to see if I finally have TCC lockup. Here's my thoughts on it, feel free to chime in...

In a first gen, if you disconnect the tach wire (The PIP signal) the PCM shuts down TCC lockup. I know this when I was installing the message center in blue. And it was really by accident that i discovered that.

On EEC-V, the electronic ignition duties are housed inside the PCM itself...there is no external Ignition Module like there are on first gens. So the only signals that the EEC-V have pertaining to the ignition is cam and crank sensors. The cam sensor just merely helps the engine start sooner. The crank sensor is what KEEPS the engine running on EEC-V, and thus tells the PCM the RPM speed and when to activate spark and fuel (The SAW signal). Since that has been neglected to be hooked up by me thus far, the EEC-V PCM has had no idea what the engine speed is, just transmission and vehicle speed.

You would assume that it would be able to extrapolate engine speed based on VSS and different tranny speeds, thus why I have had shifting. But the PCM does not have a Failsafe program that takes into effect a running motor with a crank sensor circuit failure (no crank signal and no cam signal = no start)

So yea, thats my reasoning...doesn't mean it's right or correct, just what ive been able to guess while loosing sleep

so have you had any improvements on gas mileage?

Well, that was a bust...sort of. Hooked up the crank sensor and was hoping everything was magically fixed. I was wrong

BUT...

I did notice a couple of other changes. First of all, 1-2 engagement is a lot sooner now and 1st gear feals more responsive. Second, my 2-3 flare, which was happening TWICE believe it or not, now is only doing it once, and is less pronouced, so I guess that is an improvement. Still no TCC lockup though.

So my next step is to hook up the laptop to the OBDII side, and record a data log and see if all solenoids are being commanded to activate when they are supposed to. That should tell me if the issues are mechanical in nature (bad solenoids) or wiring (shorts) or PCM isn't commanding TCC lockup in the first place.

Fordexplorerguy1 said:

so have you had any improvements on gas mileage?

Click to expand...

Ive only driven maybe 300 miles on the new tranny, but gas mileage seems the same, but keep in mind i drive about 75/25 city/highway, and with no TCC lockup, I can accuratly describe mileage until everything is working properly. I am averaging about 17.3 MPG according to the message center (which will always be off about 5-10% in nature anyway) :

Well, here is the wiring diagram for those wanting to attempt this I warn you though:

"with any and all modifications you do to your explorer, i am not held liable or responsible for shorted out wires, electrical fires, or transmission based explosions. Attempt this at your own risk. I post this before I have mine working properly and 100% so to the best of my knowledge, this is complete."

Enjoy

(5R55E Wiring Diagram PDF Download)



A Few Notes Regarding This Spreadsheet

You may notice some rows are grayed out. This is because you will not be using these wires. For instance, the 5R55E transmission harness has two O2 sensors integrated into it. Obviously, we will not be using these. ALSO, the harness has the integrated VSS wires. For 4WD applications, these wires will also not be used for two reasons: 1) you use the VSS signal from the EEC-IV harness, and 2) the first gen VSS wires are in the transfer case electrical harness. So either cut or remove these from the 5R55E transmission harness completely or just zip tie out of the way.

And here is a farely updated parts list for everything.

Parts Required:

1997 PCM
The code doesn’t really matter, just got to make sure it’s a 97

1996-2001 EEC-V PCM Connector (104 pin)
Note: Ideally, get the same connector that the PCM you will use came from. Get as much of the electrical pigtail as possible. But if you can’t, any EEC-V connector will work, just some re-pinning will be in order as well as some wire colors may be different. GO BY PIN NUMBER!

1997 5R55E Transmission
It has to be 97 because in 98, a couple of sensors got deleted that the 97 PCM
needs to shift.

1997 5R55E Transmission Harness
This has also got to be from a 97 for said sensors.

OBD-II Data Link Connector
This is the trapezoid shaped connector located under the dash of all OBD-II vehicles. It will have seven wires, but only six will be needed. Get as much of the electrical pigtail as possible

A4LD Shift Cable Bracket
Use can use the old one and attach this to the 5R55E transmission to flip the shifter cable 180 degrees.

A4LD Dipstick Tube & Stick
You will reuse the dipstick tube from the A4LD and attach it to the 5R55E, because the 5R55E is much longer

Transmission Control Switch
In its most basic form, it’s a momentary switch with a light. This mimics the O/D OFF button located on the drive selector of 95-01 Explorers. Ideally, you want the second gen stalk and wire the button in and mount the light as you please. But a simple momentary contact switch will work. But this is needed in any fashion for the PCM

Parts Optional, but recommend:

Rotunda Monitor Adapter Harness, part number 007-00081
This is an extension harness designed for the EEC-IV computer systems. If you want a truly plug and setup, I highly recommend finding one and buying it. When you splice all your engine sensors, you can simply do it in this harness and plug everything in when your ready. It’s not needed, but if you don’t get it, you will have to sit in the truck in the lower cab corner, and splice everything in that small space. Not Fun.

Connectors C113 and C118
These are the male electrical connectors that plug into the 5R transmission harness. These will need to be cut off the engine harness.

A4LD Neutral Safety Switch
This is the round 5 pin switch that is installed in the A4LD and has the round female connector that attaches to it. This is what is used to integrate all the safety switch functions of the 5R DTR Sensor and moves it to the first gen harness.

A4LD Valve Body Electrical Harness
This is used to connect to the ignition power source already running down to the transmission to the 5r solenoids and sensors. Also you use this harness to attach the resistors to the A4LD 3-4 and TCC solenoid wires to prevent MIL’s.

Second Gen Gear Selection Display
I have not hooked this up yet, but I am sure it can be modified to work. The first gen gear selector has P R N OD D 2 1, where as the second gen has P R N D 2 1 so the the 5R will not line up correctly. If this doesn’t bother you, skip this part. If it does, find a way to modify it.

Assorted Factory male/female electrical connectors
You can’t have too many of these. These are useful when attaching different harnesses together and for future use when you need to remove or disconnect something.

Thanks for sharing your hard work, you'll get it figured out in the end.

What problem were you having before the swap? TCC not locking? I wonder if there was an existing issue with the truck (some input) that was preventing TCC lockup and is still causing the problem? Maybe the 2-3 flare is the normal 5R55 syndrome?

You probably have already considered this. Again, wow and thanks for sharing.

The problem I was having before was that the tcc lockup was always on, and thus burned up the clutches. ill know more when I can get my laptop hooked up to it and go for a drive

Gotya. I will add the inputs needed by the PCM to allow lockup for other's info. You probably had a valve body problem or a grounded TCC solenoid wire:

1-ECT (engine coolant temperature sensor) no lock until engine is warmed up
2-BOO (brake on-off switch)
3-EI (electronic ignition) consists of the CKP, EI module, PCM. The EI module generates the PIP signal necessary for the ECM to allow TCC lockup. Also mentioned is the hall effect device in the distributor. Hmmm, I thought that was with the Thick Film Ignition systems. Ours are distributorless.
4-TP (throttle position sensor)
5-PSOM (programmable speedometer/odometer module) receives signal from the RABS (rear antilock sensor). The PSOM relays vehicle speed to the PCM. I am guessing 4 wheel antilock models have a different setup? I don't think I have a rear sensor (4 wheel ABS)...
6-VSS (vehicle speed sensor) also would result in no cruise control

(Info from the A4LD Ford manual)

wood1 said:

Gotya. I will add the inputs needed by the PCM to allow lockup for other's info. You probably had a valve body problem or a grounded TCC solenoid wire:

1-ECT (engine coolant temperature sensor) no lock until engine is warmed up
2-BOO (brake on-off switch)
3-EI (electronic ignition) consists of the CKP, EI module, PCM. The EI module generates the PIP signal necessary for the ECM to allow TCC lockup. Also mentioned is the hall effect device in the distributor. Hmmm, I thought that was with the Thick Film Ignition systems. Ours are distributorless.
4-TP (throttle position sensor)
5-PSOM (programmable speedometer/odometer module) receives signal from the RABS (rear antilock sensor). The PSOM relays vehicle speed to the PCM. I am guessing 4 wheel antilock models have a different setup? I don't think I have a rear sensor (4 wheel ABS)...
6-VSS (vehicle speed sensor) also would result in no cruise control

(Info from the A4LD Ford manual)

Click to expand...

All of which is 'hooked up' to the 97 PCM. I am seriously thinking i have a mechanical issue in the tranny. As soon as I can find a power inverter, ill take the laptop on a drive with Blue and data log.

pardon me if i have missed this, so what have you done about the OD on/off switch in this

you run a separate switch for it or ?

Right now I have it rigged up as a temporary switch and light. Im eventually going to swap over a second gen gear selector lever to my first gen steering column. That way I have the stock O/D button. The light Im still working on how I want to do that.

ok, went to a ford dealer today and paid a tech 20 bucks to go with me on a test drive and hook up their IDS system to Blue to diag why there is no TCC lockup. I wanted to see if the pcm was actually commanding the solenoid to activate or not. After the test drive, we determined that the TCC was NOT commanded to lockup, so that leaves me to look more at my wiring. Did get an extensive list of codes.

The only important one was a P0320 code which has to do with the electronic ignition, which i will admit was one of my concerns.

Long story short, the 97 PCM is not getting the IDM (Ignition Diagnostic Monitor) signal from the coil pack, ergo its getting a sparatic PIP signal. This in turn can make the shifts hard, slow engagement of shifts at WOT, and NO TCC LOCKUP. All of which I am experiencing. So my solution?

Add a freaking ignition coil, LOL

Actually, add a dummy coil to the 97 pcm (4 wires) and see if my shifts are better and if I gain TCC. So that's my next step.

OK, so the transmission is possessed :

Not really, lol. So I hooked up a secondary ignition coil to simulate the missing IDM signal that was causing the P0320 code, which in turn I THOUGHT was causing my lack of TCC lockup. I also reset the 97 PCM by unplugging it for good measure.

Went on a 30 mile test drive and STILL no TCC lockup Although i have noticed that everytime i add something to the system, the shifting changes slightly. For example:

With crank sesnor hooked up by two flairs calmed down a bit and went to one flar (a 3-4 flair)

With coil hooked up my 3-4 flair is intermittent...on last night's test drive, it was VERY bad, yet this morning it's no longer there. Truck gets up to about 45 MPH at a quick pace though

SO.....next step is hook the laptop back up to the truck and do some more extensive searching to see why there is no command being sent to the TCC solenoid. ANYONE with a specialized 5R55E book is more than welcome to chime in here : Thanks a lot guys!

Just found this while searching...

2000StreetRod said:

The PCM will not lock the torque converter when it is operating in open loop.

Click to expand...

I feel like a complete dumba** now "Insert DUH moment here"

Russell, you stupid

dogfriend said:

Your Explorer has a specialized type of control system: EEC stands for Electronic Engine Control. The Ford EEC system uses a microprocessor (PCM or Powertrain Control Module) sensors (O2, IAT, ECT, MAF) and actuators (fuel injectors, IAC, EGR) to control engine operation.

There are other types of control systems (e.g. a system used to control an elevator in a multi-story building or a control system to guide a missile to its target). The other types of control systems also use a microprocessor or a PLC (Programmable Logic Controller), sensors and actuators to control their systems.

A closed loop control system is a special type of control system; it uses a sensor (or sensors) to monitor the operation of the system and feeds the sensor data back to the microprocessor so that the operation can be tuned toward the "ideal" process. The closed loop system (if designed correctly) will correct itself for "ideal" operation.

An open loop system does not use a sensor to "feedback" info; therefore open loop systems can drift away from the "ideal" operation with no way to correct itself.

I am oversimplifying this drastically; there are books and college courses devoted to the design of control systems. It is taught as part of Mechanical or Electronic Engineering coursework. There are companies who specialize in designing and manufacturing control systems for all kinds of applications.

Click to expand...

Which i believe is exactly what my 97 PCM is doing...I accounted for all the MIL's i would get not hooking it up to a any engine controls or emission systems, but one thing I did NOT take into consideration is open loop. With out data from say the lack of O2 sensors, the pcm CANNOT enter closed loop even if it wanted too...thus no TCC lockup.

This is a set back, BUT at least i think I know I am in the right direction now. SO....

How do you fake out a PCM with 'sensor' values :

Which sensors is it not seeing?

I thought that all of the sensors were connected to both systems?

Russell, When you look at such a big picture it can be really easy to overlook such a small thing. I would consider contacting someone who can write custom pcm tunes about simulating the signals needed for closed loop, or look into dummy sensors for the
o2 sensors, they dont need to be accurate anyway, you just need a signal

Maybe James could help?