My E4OD went out in my 91 Bronco. I replaced it with a reman tranny and i have good reverse, really sluggish in D like its in too high of a gear, and a little sluggish in 1st. It wont down shift or upshift. I found that i had a Super Chip on the EEC and took it off due to corosion and broken connections. Cleared all the fault codes and tried to drive it and all was same. I look under the truck and found that the 2 sets of wires, goin to Park/Neutral Switch and Shift Solonoid Pack, was messed up. The wires were stripped back about 1cm and half of the wires were melted together. So i cut the wires and rewired all of the connections and done it all the right way. Test drove it and still nothing new. Im thinking either bad EEC or bad tranny. Yall tell me. Thanks.

 

Could be the Park/neutral (Transmission Lever Position Sensor) switch you mentioned earlier designs had problems with moisture in the swich and connector.
NAPA lists it as a neutral safety switch. Replacements come with new connector for wiring cost around 50 bucks..

 

I already replaced it. Along with the new connector.

 

I am not sure if you can but you could try and find the pressure in the tranny at different positions. The bad ECU could be the culprit especially since a PO may have messed let the computer get moisture in it and corroded connections. It is difficult to say but if the previous tranny acted similar then I would guess the computer but it is hard to say.

 

PULL CODES

whats the tranny telling you? who did the tranny replacment? if it was a shop i would be raving mad and make them fix it on there dime. how does the tranny fluid look? is it full

 

tranny fluid is good and full. i replaced it myself and have done trannys before so im confident with how i did it all. i checked the line pressure and it is way high. it slams into reverse really hard but acts like its too high of a gear in drive.

 

If pulling the codes doesn't yield anything definitive, double check everything in the wiring surrounding the MLPS (Manual Lever Position Sensor). The situation you described sounds fatal for a transmission that relies solely on electronics information for its shift parameters. Shorted or damaged wires in this area can kill internal switches and solenoids causing untold problems. If this problem existed AFTER the tranny was rebuilt, there is a potential for damaged internal electronics.

On a side note: There was a recent thread that mentioned the possibility of opening up an MLPS and taking readings across the contacts inside for just this reason. I don't know if anyone has done it yet but now would be the time to find out just what those values should be through this critical component.

 

there were melted wires going to the solonoid pack and going to the MLP so i replaced the MLP and the connector for it. I also repaired all of the wires. What do you mean by internal electronics? The Solonoid connector is recieving 12v on one pin and 5v on another pin, and a ground. The company that i bought the tranny from told me that either voltage is not gettin to the solonoids or the control module is messed up. Im leaning towards the EEC because of the bad Super Chip on it and that side of the truck has been sunk under water.

 

The solenoid connector is on the side of the transmission... the solenoid(s) are INTERNAL to the transmission itself. They trigger shift and fluid pressure changes.

If the truck will start and run the PCM is fine. Obviously the 5VDC reference voltage (VREF) power supply is not damaged and you are getting battery voltage as well. Pull the codes first. Kemicalburns is right. Otherwise you are chasing ghosts and throwing time/money at things that may or may NOT be the problem. If you GET codes back out of the PCM, that too indicates that its highly unlikely that the PCM is the problem child.

 

Greystreak--Maybe it was you and I that talked about opening up the MLPS earlier. I did not find an extra one to open up---still looking for a bad one to open up.

By my 93 EVTM, (should be same wrg as 91) it is fed from the PCM (probably 5V, not clear) on 48 then through the MLPS resistors and back to the PCM on 30. The MLPS is 6 resistors, in series, that give a varying resistance (or voltage, depending upon what the PCM is reading). P is at the start of the string and reads through all six resistors. Following in order are R-N-D-2-1, each step drops one resistor in the string.

The EVTM test procedure gives ohm reading for each position. By doing the math, you can determine the resistance of each resistor in series.

P---3770-4607 Ohms
R---1303-1593 "
N---660-807 "
D---361-442 "
2---190-232 "
1---78-95 "

Conn 1012 is at the MLPS and only has 2 wires, GY/R (to 48 PCM) and LB/Y (to 30 PCM)

The E4OD should have 9 wires going to it, through 3 connectors (C110,C1048,C103). 2 wires, R & W/R have 12V from the PCM power relay in the fuse box. 1 wire is the same wire from the PCM 48 that feeds the MLPS also and goes to the TOT (transmission oil temp sensor in the solenoid pack also) and back to the PCM. The other 5 wires go to the solenoids and back to the PCM which supplies the GRD/RTN to operate the solenoid and make the shift. All the solenoids are fed 12VDC on a common bus and are operated, individually, from the PCM control.

Sorry if this looks like a bit to try to read through. If you want to help yourself and your wallet, you need to try to get a grasp on these electronics. It isnt rocket science----even I eventually caught on I also used to be a migrant wire picker (retired)

 

OOPS I misled--1012 has more than 2 wires, actually ~8. only 2 are for gear selection of the E4OD.

 

I would throw a fit with the company that sold you the tranny. If you are getting consistant voltate at all the pins on the tranny, then the wiring in the tranny is the culprit and they sold you a POS rebuild.

 

It seems as if the tranny is locked in a safe mode through to PCM?

 

It is possible, but the truck only supplies 12v, and the computer usually has reference voltages of 5 volts. If the truck is slamming into reverse, it is probably a safe bet that selinoids in the tranny are experiencing problems.

 

Anything the tranny does is through the PCM. It may not be in the wiring to the tranny, it may well be in "limp home" mode caused by a hard code set in the PCM. That can be caused by many things. My 93 goes into limp home when I was having hard troubles (codes) caused by some fuel problem at idle (FPR,Fuel pump, filter etc). When I found a temporary fix (removed vacuum line to FPR and plugged it), it came out of limp home mode and is functioning normally. I forget just what all limp home mode does to the tranny, but it goes to a bare mimimum just to get the vehicle to roll (AKA "limp home").

I would say first to check all the wires (you indicated some wires at the tranny were burned) and make sure they are good. I can send you the 93 locations of all the connectors and colors, maybe ALLDATA will have a schematic for 91.

Good news is your tranny may just be O.K.----Bad news is you may have to spend time/effort (lots of) to chase down the problem elsewhere A word of caution that I have needed on occasion-----Check REALLY good before you show your azz to anyone, sometimes it bites you.

BTW---on the MLPS chart of resistor values, it appears (1st glance) that each successive change of the shifter cuts the resistance in half of the previous value. To go from P to D is quite a change in resistance.