All

Been doing alot of thread search but have not found an answer yet to my problems.

My 2000 Excursion (4x4) 5.4 L, 170,000 miles, threw these three codes:

P0743 - Torque Converter Electrical Circuit
P0755 - Shift Solenoid B Malfunction
P1747 Electronic Pressure Control Solenoid - Short circuit

It drives in all gears but accelerates slowly, it only creeps forward in first from a dead stop and really bogs down in Drive but Drive seems ok once the speed is up.

I first thought it was the solenoid pack, so I replaced it, with no improvement.

In a dumb move, I decided it was my torque converter, replaced it ( after a couple of weeks of effot and pulling a tranny for the first time) No improvement.

I am now stumped but thinking maybe something wrong with the valve body, this is a guess so I would like any suggestions about what else to look at and research before I dig into it again one more time.

Probably goes without saying but I am not willing to shell out the dough to bring it into a transmission shop for a fix. Looked into this already and pretty much only thing they want to do is sell me a rebuilt tranny.

All help and suggestions are appreciated.

 

I hear ya. Now that you have the experience of R&Ring it I would get another box from a wrecking yard and I think most will gaurantee them to work. I have spent a lot lot of days hanging out in wrecking yards and rarely buy new parts. Your whole truck is used parts!

 

Replacing it with a used one is a good suggestion and something to consider and may do if the tranny is truely toast. I have not been able to convince myself yet that this is the case.


thanks for the input.

 

Pick the brains of the experts in the tranny shops. Some will be helpful. It might not be toast but all the seals could be hard among other not so obvious things. If it smells burnt it probably it on the way out. The problem is there are so many parts in them and many are inaccessable. I used to rebuild them and the never ones have more electrical parts in them.

 

After you change the transmission and it still doesn't work, and that is what will happen, come back here and we'll help diagnose what's wrong.

Changing the transmission at this point in the diagnosis is just as dumb as changing the torque converter when there is ZERO reason to change it. I can't see how anyone would change the converter based on the codes that are listed here, other than EVERYONE knows that the torque converter is ALWAYS what's wrong with these transmissions.

This truck has a wiring issue. It probably is a ground, but it could be on the power side, too. Someone that is really good at diagnosing wiring issues could find this very quickly. I can't do it over the 'net.

I'll bet if you had taken it to a good shop at the start you would have had it fixed for less money than you spent on the torque converter. And now you still have to get it fixed.

 

Mark

Thanks for the caustic suggestions ( I think). For what it is worth, I did take it at first to AMMCO, who diagnosed it as needing a new torque converter at the very least. So taking it to tranny shop ( how dow you know which ones are good?) is not so easy and guranteed a fix.

Do you have a good wiring diagram and series of tests to recommend for this fix?

 

Don't direct caustic to me, I am just trying to help you.

 

That's why I said to pick their brains, maybe 1 or 2 will befriend you. I went all through this years ago when I had more tools and inclination than I had money.

 

Ok,

I was able to find a good diagram, traced the wires up from the solenoid pack to where they connect near the power distribution box. These all appear fine without a short. After this, at the connector where they then feed into the PCM, I did find the red/yel is shorted to ground. I think but not sure, that the red/yel is the power and should not be going to ground so it appears to me that their is short from this connector into PCM, or the PCM is shorted.

I tried my best to disconnect all the other connectors that share the Red/Yel lead into the PCM and rule out a short at the EGR, and O2 sensors, etc.

I am in the process getting access to the PCM to investigate further. Let me know if you think I am wrong the track.

Mark and others, your help is appreciated.

 

I'm done here

 

OK, I found this out. Try as I might, I cannot find a red/yellow wire to the PCM on my wiring diagrams for the 2000 year 5.4 excursion. The info is on the engine controls 5.4 L page of the ford service manual DVD.

The closest I could find is there is a red/white from the central junction box (power) to the PCM on pin number 55. I put the diagram up in my Gallery in the miscellaneous section.

Bion

 

Thanks Bion, you are right, no red/yel going to the PCM. It goes into the TC indicator lamp and come out as tan/wht into the PCM TCS and wht /lt grn into the PCM trans ctrl ind.

I need to figure out if this red/yel should be grounded as I measure it. I see it as hot in run or start from the central junction box, and perhaps hot from the PCM power relay.

Thanks for the help

 

Hey I am having the exact same problems as you are with tranny and the exact same codes. I have a 2002 E250 with only 65k miles on it. I changed out the solenoids but did nothing and still have the same codes. My Over drive button (TCIL) on gearshifter has not worked for at least a year but van ran fine. So when the solenoid codes popped up and the fact the van is barely driveable i checked the TCIL. I did have a short and /or open circuit the wire comin down the gearshifter which had rubbed raw as you move up and down on the gear shifter. Well i got all new shifter that came with wiring and switch. Replaced the solenoid but no improvement.

I did notice a lot of metal particles in pan when i changed the solenoids, some resembled small parts of needle type bearings? Did you figure out problem? Any help would be great because I am stumped and this is my work van so every day not on the road I am losing money.

Getting ready to have van towed to Ford dealer...

Please Help anyone

Thanks

Chuck

 

OK, I did some studying of the 5.4 A/T tranny ckt diagram(I'm using the one from shopkey, so I'm putting my money on it being correct).

I need you to troubleshoot with me. A multimeter would be really nice, if not then a simple test light could be used. THESE INSTRUCTIONS ARE FOR THE EXCURSION, WE WILL WORK THE ECONOLINE NEXT. Read the theory of operation, then the T/S steps will be below.

All three of those items are powered from the SAME input voltage. It's yellow/black coming off of FUSE 113 in the underhood fuse box, goes thru the PCM POWER RELAY, coming out a VIOLET wire back into FUSE 19 in the underhood fuse box, DEPARTS the fuse box a RED/YELLOW wire. From there it goes to a split, named S122, apparently near the dash(not sure why?), to another split at a point called S138, apparently in the backup lamp harness. From there it goes to the TRANSMISSION CONNECTOR, PINS 1 & 12. Power on pin 12 is distributed to the TORQUE CONVERTER CLUTCH SOLENOID, COAST CLUTCH CONTROL, SHIFT CONTROL 2, & SHIFT CONTROL 1. Power on pin 1 is distributed to the ELECTRONIC PRESSURE CONTROL SOLENOID. Those Items in blue all relate DIRECTLY to your codes, so this is why we are troubleshooting the voltage here. Goes without saying, but if either of those fuses is blown, replace, clear code, check drive, re-check fuse, cause when they blow, it was for a reason and may have blown again.

STEP 1: Is your third brake light burned out? Please don't ask me to explain this one, just check, and change it if it is. If it was burned out, clear codes, drive to see if problem persists, if so, continue to STEP 2. Again, please don't ask to explain this part.
STEP 2: Pull FUSE 113, check for good voltage on ONE side of it's plug(won't be on both since the fuse is pulled). You will probably get voltage here since the fuse box is immobile and unlikely the cause. If good reinstall the fuse, if bad, find a way to get voltage to it. On to STEP 3.
STEP 3: Pull FUSE 19(20A fuse). Turn Key to the RUN position, this will engage the PCM POWER RELAY. Check for Voltage on ONE side of the plug(same reason). If bad, suggest replacing Relay, and repeat test(keep in mind, I'm not getting into that fact that the Violet wire off the relay goes two places, mostly because I'm expecting the relay is good). IF voltage was good, turn car off, reinstall fuse, turn Key to RUN, check for the same voltage at the same fuse(check at the metal tabs on top of the fuse). WE are now testing to see if it is shorted past this point, if the voltage is gone we DEFINITELY have a short. Continue to Step 4
STEP 4: Time to get dirty. Remove the transmission Connector on the transmission(this isn't the DTRS, I believe this one plugs in on the passenger side closer to the rear of the trans before the transfer case, it should plug directly downward.) IF you previously measured a short, or didn't get voltage at the fuses during any previous steps, REPEAT STEP 2 and 3, check to see if the voltage has reappeared at the fuses. Im suspecting a shorted solenoid, or a shorted wire. Continue to step 5.
STEP 5: With the transmission plug still disconnected, and the key in the RUN position, we should see 12 Volts on pin 1 & 12(both of these are still going to be red/yellow). If you are missing voltage on either, then I suggest you switch to a resistance reading and check for ground on either pin. ALERT, THIS IS WHERE WE MAY FIX A PROBLEM WITH A PERMANENT MODIFICATION. IF either wire is missing voltage, BUT one wire has voltage, you are going to CUT the non electrified wire about 4in from the plug, and short it to the electrified wire.(an inline splice would work great here, as someone should have told the for transmission engineers). IF you have good voltage on BOTH wires proceed to STEP 6, unfortunately this is where it gets a tad bit more complicated.
STEP 6: According to the wire diagram, all the input power is being supplied to solenoids, about 5 of them, which means to a multimeter you will only read a very low(or no) resistance across each of the solenoids. The wires we will be working with are as follows, all located at the transmission connector. White/yellow, pin 11, output of the Elec Pres Control Sol.; Violet/Yellow, pin 4, output of the Torque Converter clutch sol.; Violet/orange, pin 2, shift control 2(also known as SS2, or shift solenoid B). Turn the vehicle off, disconnect the red battery cable and all the connectors attached to the PCM(all because I can't remember if you have multiple, and if so which one it is)(battery disconnect is more for safety of the PCM). Now, for the resistance checks. IDEALLY you would check from the pins on the PCM connector to the pins on the transmission connector, UNFORTUNATELY, that requires multiple sets of hands and a really long test lead. If you have those items, then I will list the pins you will test below this step and you will be looking for a low/zero resistance. IF you don't have those items, thats ok, we can almost do the same thing. Attach one test lead to the chassis, make sure you have a GOOD connection, in fact, first thing is to test that connection by touching another part of the chassis and looking for lo/zero ohms/resistance(or the light comes on a powered tester). Check each pin, 11, 4, and 2 against the ground. IF any of them give you anything BUT a hi resistance/no light condition then that line has a short and will need to be replaced(don't waste money on a wire harness, just get some 16 guage and zip ties, cut at each end of bad line and run the new one inline.). IF each wire test good, no short to ground, then that means you have NO shorts in the SYSTEM WIRING. Having said that, you should be able to connect everything BUT the PCM connector back and we will move on to testing for the voltage at the PCM. Keep in mind, we just skipped clear past testing the solenoids in question. If you can get a mirror and some space, then we will cover that portion two steps from now. The reason we aren't testing each of them is Because they are solenoids, and appear to always have a short, and will test as such. Their is no reason to assume more than one solenoid broke at the same time which is why we are looking for a open/short wire outside of the transmission. The pins on the PCM are as follows: White/yellow, pin 81, EPC(this comes from the elec. pres. cntrl. sol.), Violet/yellow, pin 54, TCC(torq convert clutch sol), Violet/Orange, pin 11, SS2(aka shift cntrl 2, shift sol b). Proceed to whatever long-winded step I came up with next.
NEXT STEP(lost count): Everything connected normal, with exception to PCM connector(s). Turn Key to RUN. Verify one more time you have good voltage at FUSE 19(using top posts, leave fuse in). Check each of the THREE previously mentioned pins(11, 81, 54) at the PCM for Voltage(not sure what should be here, but it should be above 2 and I think less than 11). If you are missing voltage on any of those lines, then you have a broken(open, not shorted) line, or a bad solenoid on that respective line. If all three are good, then My LAST recommendation is replacing the PCM, as it shouldn't be popping a code if all three of those are good signals.
LAST STEP: If nothing else appeared bad, or you don't want to replace the PCM yet, or you just want to know for sure, then you can pull each solenoid out individually and inject a voltage and ground to see if it engages(problem is I can't even picture in my head what these specific solenoids look like, or if you'd be able to hear/see them engage).

Hope this helps and saves you some money. If it's the PCM, carparts.com, get the EXACT part number you have on your current PCM, or it AINT GONNA WORK. Wow, I'm long winded. Dude with the Econoline, I gotta go, but I'll get you a write-up that says the exact same things, but with the correct wire colors and fuse numbers, sometime tomorrow, sorry I can't get it tonight.

-Drunken(well, not at the moment, my typing wasn't slurred)