I've got a '94 F150 with a 4.9 and the E4OD. Recently it started to have shifting problems. Rough shifting, "stalling" like it was going into netural and then generally just going spastic. It would settle down, behave just fine, then start this stuff all over again. Did the research and sounded like the classic MLPS problem. Replaced the sensor, and since the wiring connectors for both the MLPS and the tranny itself looked pretty baked, I got replacement wiring harnesses and replaced them. Stopped the shifting problems for oh, about 10 minutes, and started the whole thing over again. Read through some more postings on FTE, and thought it might just be the wiring connectors under the hood. I popped those loose, cleaned the pins and sockets up, applied silicone grease, and reassembled. Once again it stopped, for a bit.

Thought it might be throwing a code or something when it was acting this way, so I got out the trusty code scanner and pulled them. It was showing a couple of codes in memory, so I cleared them, went for a drive and waited. It started slipping and slamming again, so I stopped and pulled the codes. Got a 334, vehicle speed sensor voltage too low. Replaced the speed sensor and everything was fine- for a couple of days. Now it's back to it's old tricks. Runs and shifts like a new truck for a while then BAM! it starts shifting hard, and slipping in and out of third and fourth. You can slow down, ease off the gas and it will eventually slip back into gear but continues to shift rough. Oh and when it starts doing this, the cruise control stops working! If it happens to be on at the time, it disengages. If you try to turn it on and set it, it will not engage at all. Once it settles down the cruise begins to work again. It's also strange that all this week it seems to happen at the same time. For instance, I get up in the morning and drive to work (about a 8 mile trip mostly on the interstate), park and go into work. At noon I drive back to the house for lunch, and all is still going well. Leave the house and before I get to the end of the block it starts going nuts. I limp it back to the shop, park, and it's running great all the way home. Get up the next morning and repeat the cycle. I've gone through this exact scenario for the last 4 work days.....

The truck has 250,000+ miles on her, but transmission fluid and filter have been changed regularly since she was new. Torque converter was replaced under warranty by Ford years ago when it failed at around 30K miles. Other than that I've never had a problem with the tranny. Only a slight amout of fluid leakage is visible around the front and rear seal areas. She's a no frills daily driver. I don't tow with this truck and the majority of it's miles are interstate highway driving. Only thing I've done is add an auxiliary trans cooler. Fluid has never gotten hot, and have not seen an appreciable amount of particles in the fluid or on the magnet during fluid changes.

I'm fast approaching my wit's end. How about it? Any of you other E4OD geniuses out there have any ideas what's causing this behavior? I'm running out of ideas. Judging by the smoothness it exhibits up to now and when it's working I just can't figure it being an internal problem.

 

After some more research, came across a few postings concerning the PSOM. With the truck returning the 452 VSS voltage too small code, could this be the culprit? Anyone else seen this before? Speedo seems to work OK, but when this crap starts, the cruise control quits.

 

Webdoc58

My truck is doing exactly what you describe. It is a 97 F250 HD 4WD with 220,000 miles. I hope that you can figure it out, because I am having difficulty. See my post under the pen name "ronhrob" from yesterday. My harnesses all look like new, and the conections are still greased and free of corrosion. I am going to try another VSS from another truck and see if that fixes it, but it will be a few days before it acts up again.

I'll let you know what I find out.

Ron

 

Ron-

Check my posting in the electrical forum from today. It refers to a Ford service bulletin they may be on target. Just don't know what they are talking about under the diagnostic procedure section. I'm going to pull my pumpkin cover this afternoon and check the tone ring first and see if I can't eliminate that.

Doc

 

Pulled out the instrument cluster. Disconnected the three wiring connectors going to it. Cleaned them and the circuit board with alcohol. Let it dry and lubed the contact points up with silicone grease. Reassembled and took her out for a test drive. Runs and shifts like a new truck. It's been six days now and none of the symptoms have returned.

 

I know it has been a long time, but is your transmission still shifting correctly? I have been having a problem with mine for quite some time. It seems to be a low voltage problem. I replaced my alternator because of worn bearings with one from Advance Auto Parts along with a new connector for the alternator. With it idleing you could watch the voltage go down with a meter connected to the battery posts. So I replaced it again and had them give me the smaller pulley from a 75 amp alternator (that was what was on mine when I bought it). It has helped a lot, but if I idle for 10 minutes or so, or run the fan on high and have wipers or lights on, it will bring my in dash voltage meter down a little and start the bad shifting.

I was idleing at Hardees a few nights ago, and figured it was going to happen again. After idleing for 15 minutes or so, it suddenly increased rpms to about 1000 or so. Then when I pulled away it was shifting bad. I will start out in second and rev really high before slamming into third and stuff like that. It drives perfect until this happens. Sometimes I can drive it for days without it doing it as long as I don't have a big load on the alternator.

The transmission was completely rebuilt in 2006 and has maybe 24k miles on it. I had it checked and fluid changed twice and they found nothing wrong. I have had the battery checked from Advance Auto and it shows being good for 900 CCA. This new alternator with the 1 7/8" pulley shows about 14.2 volts at idle with no load and 14 + or - volts with a load, but it slowly drops.

I was convinced it was this 2G alternator and was getting ready to buy one from fordfuelinjection.com but maybe there is something else wrong.

Sorry for the extremely long post, just looking for some where to turn.

Thanks for any help.

 

You're right. It has been a long time. Well cleaning the instrument cluster pc board and the connectors did work-- for a couple of weeks. I finally went to the salvage yard and got another cluster from a 95 Super Duty, I think. Swapped out the clusters and haven't had a problem since then. Have you pulled the codes after it starts missing gears? In going through it, I found lots of different things to check. Start with a code scan. Check your speed sensor mounted on top of the diff. housing, and be sure to check all your wiring and connections. I don't see how your alternator output could be causing it. I replaced my stock fan with a very large electric one a couple of years ago and in the summer with the A/C running full blast, my voltage drops WAY down at idle and it hasn't caused me any shifting problems.

Good luck and keep us posted.

 

I have not been able to catch it and pull the codes yet. The only codes I have is and EGR code (I have the EGR eliminator installed yet still get check engine light) and a thermactor code (I have those disconnected as well except for the electrical conntectors), neither of which should have anything to do with the shifting problem. I will try to make it happen again and have the scanner with me. Thanks for the help.

 

Forgot to ask. Does your truck have cruise control? If it does and it drops out when the tranny starts bucking, it almost certainly points to the PSOM module in the instrument cluster. What happens is that it fails to send the speed signal to the transmission, the transmission controller gets confused, and there goes your problem. BTW, I kept the damn scanner with me for a week before I could catch it. Realized later that the code gets stored and you can pull it from memory.

 

Well, mine is not kept in memory. So either it is something that does not throw a code or only has a code while it is doing it and not storing it. I have pulled the codes several times and never got anything that should cause this problem.

 

Well it has been a while and I was about to think it would not do it again....until.....

I drove from work to the county clerk's office with no problems until I went to leave. It started the same crap as before. It revs a little high then slams into second gear. The rest of the way home it seemed to just go into gear way to early. I floored it up to about 70 mph and it shifted fine and did not slip. But normal driving is a problem.

I forgot about the cruise control test so I will try it when it happens again.

If it is the cluster, how do I go about finding out which one will work and which one will not? Also, I am assuming I will have a totally different odometer.

I have not pulled the codes since last year but I was assuming that it is still just the EGR and thermactor codes. But I will try to pull them as well.

This really makes me want to go into further debt and buy a much newer truck!

Thanks.

 

Long time! Old Blue is still running like a Swiss watch, even though I've kind of put her out to pasture since I acquired an 01 Mustang Bullitt. To answer your questions, just about any cluster from an early to mid 90's F series truck should be fine. And yes, you will loose your odometer. You'll probably have to recalibrate your speedo for your tire/axle combo, but you can find instructions on how to do that here on the forums. Good luck, and let us know how it comes out!

 

Well it has done it twice again. Both times I have been towing my boat and made a stop along the way. When I start it I could already tell it was going to do it because the idle goes up a little. Same crap of slamming into gear and shifting too soon. I put on the cruise control both time after it started and the cruise works.

So now I am not sure whether my problem is with the PSOM or something else. I really wish something would just break or burn up so I can finally find out what the heck is wrong.

 

It finally did it again today. I tell you this is nerve wracking trying to figure out because it won't do it all the time.

It does seem to be a little less harsh than it used to be. Most of the time it just goes into 2nd gear way too soon and wont down shift unless you really press the gas. Then it slams into 3rd but sometimes not as hard.

The cruise control works just fine while it is acting up. It never does it in the morning and almost never when driving home from work (except for today). It used to do it only after turning it off and restarting it back up while it is still warm (like getting gas or going to the store for a little while).

Oh yea, and it appears that the check engine light does not come on when it is doing this. Because I have disconnected my EGR and thermacter systems, I always have a check engine light that comes on after it is warming up. I noticed today while it was acting up that the CEL did not come on. Trying to think back at the other times, I don't think it come on then either.

I am curious what sensors are incharge of makeing sure it shifts properly? I know of the TPS, VSS, PSOM, and the MPLS (?). Because of the cruise working I am thinking it is not the PSOM. I had a new MPLS installed in 2006 with a rebuilt tranny. I have put about 4 TPS's on this thing in the last few years. I have only put dielectric grease on the VSS. I am just wondering what else is in charge?

Thanks for all the help.

Will

 

Hey Will. May be time to start looking at that tranny. Solenoid- somethin' may be operating intermittently. E4OD is an ELECTRO-mechanical transmission. Been a long time since this thread started, has the tranny been serviced lately?