Need help please! Shifting, limp mode, etc.

[fletcher969]

Hi all,

1996, 2.3L, Auto (A4LD?), 2wd, 190,000mi.
No idea when, or IF my tranny filter has ever been changed, or if the tranny has ever been serviced.

Forgive my lack of brevity...

For the last few weeks, my transmission has been acting up a bit. At first it was some rough shifting into 2nd and 3rd, but I changed the fluid, and it ran better for several days, then it slowly began to act up again. A week or so later I could hear a discernible "whining" sound (reminds me of a turbo charger) when shifting into 2nd, and more so into 3rd, with the shifting into 3rd being more on the rough/jerky side. For the last week or so, the whining noise remained, but the shifting into second improved (mostly normal), and is operating fine, but 3rd has regressed into what I believe is a slip (revs increase, acceleration seems to flatten, then 3rd engages a little roughly if acceleration is continuous, but smoothly if I let off the gas when the "slip" occurs). All other gears have operated exactly as one would expect...no problems.

Today everything changed. Lots of stop-n-go traffic...noticed 3rd really struggling. Got off the expressway, and no sooner than I did, the transmission started kicking out of 3rd, and wouldn't stay. Initially it tried to shift, but it would immediately kick back into 2nd. A few minutes later it started to "fluctuate" (as if continually trying to shift into 3rd, but remained in second. Eventually it got to where it wouldn't move if I had it in Drive, but it would stay in 2nd gear if I had it in the 2nd or 1st gear positions (O/D light was flashing...limp mode?). I limped it home, but it remained in 2nd gear the whole time, and it would "disengage" if I put it into the Drive position while moving. Let it sit for 45 minutes...then took it down the road to scan my codes whereupon it drove normally for about 5 minutes, then started a quick regression into "limp mode" again. Scanned then cleared my trouble codes, and surprisingly, after only sitting for 10 minutes, the tranny operated normally for about 15 minutes, then went back into limp mode again (though I don't recall the O/D Off light flashing again after it did initially).

I'm hoping this is something simple like a clogged filter, vacuum problem, or something it's not liking from the PCM or TCM, versus a trashed tranny. The fact that it runs normally after it's sat awhile, and after the codes were cleared seems to indicate the tranny is "physically" alright, but has either a heat-related or electrical problem, or something else that affects it after it has run awhile.

I'd certainly welcome anybody input or related experiences that might point me in the right direction on a limited budget.

Here are the codes I pulled today in the order listed as they have accumulated over the last month approximately:

P0125 - only "current" code. Insufficient coolant temp for closed loop fuel control (I can confirm the thermostat is inoperable, but how is this related to the fuel control, and would this explain my off-idle hesitation?...another topic perhaps).

P0761 - shift solenoid C performance stuck off (seems VERY related to my shifting problems...no? Hoping too that C=3rd...would correlate with the issues I'm having with 3rd)

P0420 - catalytic system efficiency below the threshold, bank 1 (this is an old code I keep getting...not sure if it's O2 sensor related or what.

P1000 - Continuous OBD systems readiness test not complete

P1701 - reverse engagement error (reverse has on occasion "kicked" into gear since the tranny started acting up, but it almost didn't go into reverse on two occasions after my troubles started today).

Does anybody have any ideas? I'm stuck "limping" around until this is resolved, and it's going to cramp my style very quickly if work migrates too far from home.

Please....anybody?

Thanks.

Dave

 

[fletcher969]

Nobody?

I drove my truck 16 miles today, mostly in 2nd gear (had to get to/from work). Initially it shifted into 3rd, but soon kicked out of 3rd. I persisted, and it eventually went back into 3rd when I let off the throttle. Stayed there until I had to stop. It didn't want to shift into 3rd the next time, but it "fluctuated" and eventually went into 3rd. After that, it wouldn't go into 3rd, and eventually it became necessary to place the lever into the (2nd) position as it would otherwise just rev up and do mostly nothing once I was a certain speed with the lever in the (D) position (I figure the PCM was insisting on 3rd, but the tranny couldn't).

When I got home, I thought I'd try to see if it would shift into reverse, and it did, but it was very slow doing so, and when it did eventually, it slammed into gear...and the O/D Off light started flashing. Shut it off, and here I am, disappointed there was no response to my dilemma. Anything notable in that?

Any help would be appreciated folks. As it is, I'm thinking I might drop the pan, replace the filter, check my wiring to/from Solenoid C, and hope for the best.

Dave

 

[Fordtruckman80]

Whenever the O/D Off light begins to flash, the trans goes into limp home mode, which means that full fluid pressure is put through the transmission. Full fluid pressure results in the harsh shifts you've been experiencing.

As for your codes, the only two that matter at this point for your trans issue are the Shift Solenoid C code, and the reverse engagement code.

IIRC, the shift solenoids function as follows:

Shift solenoid A-1st to 1stOD
Shift solenoid B-1stOD to 2nd
Shift solenoid C-2nd to 3rd
Shift solenoid D-3rd to 3rdOD

Your truck having trouble going into 3rd could very well be trouble with the 3rd solenoid. However, this doesn't necessarily mean the solenoid itself is bad. This problem can either be the solenoid itself, the wiring to the solenoid, solenoid engagement issues, etc. Your best bet is to ohm out solenoid C while you have the trans pan removed.

As for the reverse engagement, have you tried adjusting the reverse band? You could also be having issues with a failed reverse servo seal and gasket, or some failed reverse-involved clutches.

When you drop the pan, look for any metal particles in the fluid, pan, and on the magnet.

These are just some general suggestions. If the solenoids come back okay, and/or you find more metal shavings than normal in the pan, then you may be looking at tearing down the transmission to see where the shavings have failed or what else may be causing these issues.

 

[fletcher969]

Whenever the O/D Off light begins to flash, the trans goes into limp home mode, which means that full fluid pressure is put through the transmission. Full fluid pressure results in the harsh shifts you've been experiencing.

As for your codes, the only two that matter at this point for your trans issue are the Shift Solenoid C code, and the reverse engagement code.

IIRC, the shift solenoids function as follows:

Shift solenoid A-1st to 1stOD
Shift solenoid B-1stOD to 2nd
Shift solenoid C-2nd to 3rd
Shift solenoid D-3rd to 3rdOD

Your truck having trouble going into 3rd could very well be trouble with the 3rd solenoid. However, this doesn't necessarily mean the solenoid itself is bad. This problem can either be the solenoid itself, the wiring to the solenoid, solenoid engagement issues, etc. Your best bet is to ohm out solenoid C while you have the trans pan removed.

As for the reverse engagement, have you tried adjusting the reverse band? You could also be having issues with a failed reverse servo seal and gasket, or some failed reverse-involved clutches.

When you drop the pan, look for any metal particles in the fluid, pan, and on the magnet.

These are just some general suggestions. If the solenoids come back okay, and/or you find more metal shavings than normal in the pan, then you may be looking at tearing down the transmission to see where the shavings have failed or what else may be causing these issues.

Thanks FT80...

The only times I've seen the O/D Off light flashing (twice) were yesterday when the tranny really started giving out, and again today right after I put it into reverse (as described above). The clear majority of the harsh shifts have been without the O/D Off light flashing, and except for a few days when 2nd was shifting a little bit harsh, all have been limited to 3rd gear shifts. Initially somebody told me the harsh shifts could be a filter that was clogged or severely blocked, thereby limiting the fluid pressure, and that too would cause the whining (turbocharge) noise I was hearing, because the pump was having to work extra hard. I was going to look into that this weekend, but I've been swamped. I have no choice at this point.

What range of ohms should Solenoid C exhibit, and are there any notables about what one must do to properly test it?

Thanks again...

 

[fletcher969]

Ok...I got to reading in the manual for the A4LD tranny, and it appears that reverse and 3rd gear have something in common, which might explain why both gears suddenly are BOTH having troubles. According to the manual, the "Reverse and High Clutch E" are applied only when reverse and 3rd (and subsequent higher gears) are engaged. Now the trick is to figure out how that and the Selenoid C are related, and perhaps therein lay the problem or a path to it.

Anybody have a clue?

Aside from that, I had a look-see underneath my truck awhile ago, and nothing out of the ordinary regarding wiring harnesses, vacuum leaks, etc. Everything looks snug, although I did notice there is a "sheath" of some sort on my shift cable just forward of the bracket that holds/directs the cable snug to the tranny. Anyway, I pulled on that just out of curiosity, and it rode along the cable with some resistance, though I had it in my mind it is supposed to play a functional role, and shouldn't move along the cable like it did. Just my imagination, or could my cable be broken or damaged? I know...a little paranoid...but hey!

 

[Fordtruckman80]

Thanks FT80...

The only times I've seen the O/D Off light flashing (twice) were yesterday when the tranny really started giving out, and again today right after I put it into reverse (as described above). The clear majority of the harsh shifts have been without the O/D Off light flashing, and except for a few days when 2nd was shifting a little bit harsh, all have been limited to 3rd gear shifts. Initially somebody told me the harsh shifts could be a filter that was clogged or severely blocked, thereby limiting the fluid pressure, and that too would cause the whining (turbocharge) noise I was hearing, because the pump was having to work extra hard. I was going to look into that this weekend, but I've been swamped. I have no choice at this point.

What range of ohms should Solenoid C exhibit, and are there any notables about what one must do to properly test it?

Thanks again...

The whining could also be problems with the Electronic Pressure Control solenoid as well. Or even the fluid pump. In all honesty, I rarely see a trans filter change correct such severe problems. When I changed the filter in my Ranger, it was black, instead of the yellow that the factory replacement was. However, my trans did not have any trouble shifting, and shift response was only slightly improved.

IIRC, the 4 shift solenoids should ohm out between 22-48.

Just so you know, there are internal wiring harnesses leading to the solenoids inside the transmission. This internal harness is what usually has a problem, not the exterior harness (surprisingly)

As for the shifter sheath, that's just to protect the exposed metal section of the shift selector rod (the chrome section).

 

[fletcher969]

The whining could also be problems with the Electronic Pressure Control solenoid as well. Or even the fluid pump. In all honesty, I rarely see a trans filter change correct such severe problems. When I changed the filter in my Ranger, it was black, instead of the yellow that the factory replacement was. However, my trans did not have any trouble shifting, and shift response was only slightly improved.

IIRC, the 4 shift solenoids should ohm out between 22-48.

Just so you know, there are internal wiring harnesses leading to the solenoids inside the transmission. This internal harness is what usually has a problem, not the exterior harness (surprisingly)

As for the shifter sheath, that's just to protect the exposed metal section of the shift selector rod (the chrome section).

Thanks for the additional info on the solenoid. As of tonight, I can't get one until Monday, so this may be a two-visits-with-the-pan repair if there isn't a problem with the internal wiring harness, and the solenoid checks out...or the filter doesn't clear things up some. Honestly, I was hoping I discover the filter is so clogged the pump is almost unable to pull any fluid. It would at least be a viable explanation.

As I read the manuals, the EPC keeps lurking in the back of my mind. You just added some additional weight to that thought.

 

[fletcher969]

Update...just drove my truck about 8 miles running some errands, and grabbing some repair stuff. Honestly...the tranny was almost normal except that under normal acceleration, it wouldn't shift into 3rd. It would just rev up like one would do if a gear is missed on a manual, and do nothing. But....if I let off the throttle, it would float into 3rd, and remain there so long as I didn't give it too much throttle. It even went into OD at one point. Go figure...

 

[Fordtruckman80]

Thanks for the additional info on the solenoid. As of tonight, I can't get one until Monday, so this may be a two-visits-with-the-pan repair if there isn't a problem with the internal wiring harness, and the solenoid checks out...or the filter doesn't clear things up some. Honestly, I was hoping I discover the filter is so clogged the pump is almost unable to pull any fluid. It would at least be a viable explanation.

I personally don't feel that a clog in the filter would only affect your 2nd to 3rd shift, and reverse, as fluid is always pumped through the valve body no matter the gear. A clogged filter should affect each and every single gear. However, it could be possible that you have some kind of clog within the valve body passages, that is directly affecting the C solenoid.

By now you can see exactly why transmission shops charge so much. There are so many different problems that could cause a specific issue, and it gets really tough some times to pinpoint the exact cause of the trouble.

 

[fletcher969]

Ok...I dropped the pan. The good news is there weren't any broken parts laying in the pan. Here's what I observed:

1. Magnet: There was about a heaping teaspoon of "sludge" on the magnet. No shavings...just sludge.

2. Shaving: The There were a few (5 or 6 or so) very small shavings in the bottom, but I have no idea if that's normal or not.

3. Discs: I'm not sure where they originated, but there were 4 really small metal discs...maybe 3 mm in diameter, and about 2mm thick in the bottom of the pan (actually, one was on the pan's gasket flange, one was right on top of the sludge on the magnet, like it had just fallen on it). The only thing I noted that even looked remotely close to these were some "disc-like" inserts(?) in the gasket flange, but I didn't see where any were missing. UPDATE: This question was answered. These discs are in fact part of the gasket that was on the pan....used to keep the gasket from getting smashed.

4. Harness: I checked the wiring harness, and I can't see any obvious defects or shorts.

5. I looked at each of the solenoids, and the only thing notable is that one of them rotates a little (i.e. I can move it).

6. Fluid was red, but had a "metal flake" look to it. Like one might see in a car paint. Probably not a good sign for one month's of use, unless it picked it up from the filter. As was pointed out on a different board, my magnet might not be doing its job of picking up the "metal" stuff from my fluid. It could be it was too caked with "crud" to work as well, or the magnet is losing its "grip."

7. Filter was filthy! I'm sure, if nothing else, the tranny will "breath" a little easier when I run the new one regardless of its condition.

Unfortunately, my multimeter is stored away, and my buddy's is loaned out this weekend. I won't be able to ohm the solenoid(s). Crud!

Also, a few questions:

1. Which solenoid is C on the 4R44E? UPDATE: Never mind...I found a diagram. It looks like the solenoid I can rotate is the EPC (one furthest to the rear on the side with 4 solenoids), which has been mentioned already as a possibility. Solenoid C (i.e. #3 if that is in fact the one associated with a DTC-P0761) is on the other side in the corner.

2. Is any solenoid supposed to have any play? As indicated above, my EPC solenoid (rearmost on the side with 4 solenoids) can be rotated about 5-10 degrees in either direction with a couple of fingers. None of the others budged at all.

3. Once the valve body is wiped free of fluid, is/are there any area(s) that would continue to drip fluid? I have one area by the rear filter "hole" in the valve body, and next to it there is a spring/assembly in a recess. Fluid is dripping from that recess where the spring can be seen, and has been for well over 60 minutes.

4. What kind of indications am I looking for where the wiring harness is concerned? As it is, it all looks ok eyeballing and handling it.

 

[fletcher969]

Ok...for those of you who may have followed this thread, or for those who might venture by in the future, I finally got around to resolving most of my issues. Long story short, I tightened down the EPC by bending the bracket holding it down, checked and found nothing obviously wrong with the wiring harness or C (#3 shift) solenoid, or the EPC, so I cleaned them up, and plugged them back in. Installed the new filter, put it all back together, and filled it back up. Bottom line...except for a minor 2-3 flare and kick, all other symptoms have disappeared, including the "turbocharge" whining noise I was hearing. Operation seems much "tighter" than before, and shifts are much more refined. While the 2-3 flare is there, it shifts smoothly if I let up the throttle ever so little as the flare begins. Once in 3rd, and unlike before, it operates normally, including kick downs when the accelerator is pressed hard. Where 3rd had become a huge question mark as to whether it would stay in gear, if it even found 3rd, it now sticks there, and operates as one would expect. No issues with OD either. All I have to do now is figure out how to resolve the 2-3 flare, but even if I never do, it's gone from unreliable above 30mph to a not-perfect, very drivable transmission now.

Oh...forgot to mention...it is a little slow shifting into reverse, but it otherwise operates normally.