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HDGENE, Ford Senior Master/Diesel/Trans
Category: Ford
Satisfied Customers: 5647
Experience:  25 years Auto experience, Ford ,GM, Chrysler, Asian & European
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Hi, let me try and be some help. The instrument cluster goes dead while driving and at the same time the trans slips into neutral or you are having two seperate problems at different tiems? How long ago was the trans rebuilt or was it just done and you are still having concerns. Did the dash problem start after the trans was removed? Do you have access to a scan tool to check for codes for the engine/trans?
Customer: replied 5 years ago.
no codes engine or trans. trans was rebuilt about 4 mos ago. Complete with valve body and solonoid pack, has never been right . dash cluster started this morning.
Ok the dash itself is a module the HEC module you will need a scan tool capable of communicating with the hec module to see if there are any codes in it or if you can communicate with it.There is a good chance the cluster itself is going bad.Other things to check are all the ground connections to the trans coming off the battery and make sure they are hooked up properly. if the trans was rebuilt 4 months ago I would think it would still have a warranty on it. it slips out of gear when it hits 4th gear/od? or any gear at anytime
Customer: replied 5 years ago.

Trans. has gone back 3x and they have checked all their work and replaced parts just to make sure they weren't defective. They are scratching their heads too! Sometimes the car will be fine for quite a few miles and then it starts again - slips out of gear when it hits 4th gear/od. All the wiring has been checked, wiring harness has been opened up and checked and everything inspected. Been on line and noticed that there are numerous complaints with this particular problem. Don't know what else to check! What are we missing?

The transmission range sensor can be bad. This sensor mounts behind the shifter linkage and tells the PCM what gear the shifter is in PRNOD21. If it reads neutral when it goes to shift it will go into neutral. This is a common issue on many vehicles.You can verify by monitoring the input for the sensor and wiggling the shifter. But would be a good possibility. Monitoring the PCM command for what gear it is in when it slips will also tell if it is commanding 4th gear or neutral.
Customer: replied 5 years ago.
Trans. range sensor has been changed. If you toggle the overdrive sw. on/off from 4th to 3rd then back again, over drive works for a few more miles then out again.
Ok the most common thing for it to slip into neutral is the shift solenoid A failing, there might be some debris in the screen for the valve body that supplies fluid to the solenoid. Also since the trans has been rebuilt they might have used too much sealer at the end cover of the trans and blocked off one of the line pressure supply ports. A line pressure test with a gauge should be done to verify line pressure when the concern occurs as well as checking if the shift solenoid a is flagging a fault. this is done using a scan tool that can view live data from the transmission. the trans shop should be able to verify this concern and have the proper tools to repair it. Long as the TR sensor is reading OD then the PCM will command 4th gear and it should go in and not slip. Other possibilty is a cut or nicked seal allowing the clutch pack to bleed down internally.
Customer: replied 5 years ago.

Will get back to you soon.

Ok let me know if you need more help and dont forget to hit accept when done if I was helpful
Customer: replied 5 years ago.
Pressure testing shows all in spec. Are there any common electrical problems, such as wires getting pulled on and pulled apart. Wondering if this is more elect. than mechanical problem. Something other than what is in Technical Service Bulletins that we have access to.
For it to be intermittent anything is possible, ground wiring is critical on the focus as it is on other models. I would double check all ground wires and connections if one is loose or a bad connection it can cause weird concerns
Customer: replied 5 years ago.

Re-checked all connections-all O.K Took out for another drive - Not the first time that we noticed that when cold engine it will take about 4-5 miles B-4 the Trans. will give a shudder then start missing 4th/OD. Is it possible that the casing is warming up after 4-5 miles and causing this problem? Would this be a heat problem of enough magnitude to damage any sensors in a way that can't be seen? Would even the Tranny Guy not be able to tell if it's the casing? Put so much time and effort into this and I hate to think

I have to refund cust. all this money but, don't know what else to check.

but it is going into neutral or it shudders first then goes into overdrive just want to clairfy we are talking about the same type of issue. The case can be an issue but you should be able to see that when checking the line pressure when it acts up
Customer: replied 5 years ago.

Going along about 40-45mph - then feel quick little shudder and then second or two later nothing when you press on gas feels like you are in neutral even though scanner

shows Im still in overdrive. Cust. doesn't always feel shudder - they just know that they start slowing down and there's nothing there. My foreman has more than 25 years of exp. and he says he's never run into a problem like this before.

Sounds like when it is shuddering there might be an issue with the direct clutch for 3rd gear. when it shifts into 4th it applies the 2-4 band servo, did you replace the servo piston for the 2-4 band? Does it try to shudder if you accel hard in 2nd gear? I am thinking the direct clutch might be dropping out but you say line pressure is good even though it goes into neutral?


Line Pressure Chart

4F27EP, N345-450 kPa50-65 psiN/AN/A
R450-585 kPa65-85 psi1,930-2,310 kPa280-335 psi
D, 2, 1345-450 kPa50-65 psi1,240-1,450 kPa180-210 psi

Line Pressure Diagnosis Chart

Test ResultsPossible Source
Low pressure in all rangesWorn pump.
Low pressure in all rangesFluid leaking from pump, main control valve body or transaxle case.
Low pressure in all rangesPressure control solenoid inoperative.
Low pressure in all rangesSolenoid regulating valve sticking.
Low pressure in D, 2, 1 onlyFluid leaking from forward clutch hydraulic circuit.
Low pressure in 2Fluid leaking from intermediate/overdrive band hydraulic circuit.
Low pressure in 1, R onlyFluid leaking from low/reverse clutch hydraulic circuit.
Low in R onlyFluid leaking from reverse clutch hydraulic circuit.
High pressure in all rangesPressure control solenoid inoperative or open wire harness.
High pressure in all rangesPressure regulator valve sticking.
High pressure in all rangesPCM inoperative.

Customer: replied 5 years ago.
Hi again, I will get back to you tomorrow, since we will be checking everything AGAIN, and also want to talk to tranny guy. If I haven't already said so already, thanks for sticking with this/us!!
No problem just trying to help if I can I have built plenty of these 4F27E transaxles direct clutches, the end plate at the back of the tran wiped out,the 2-4 band sticking and debris in the screen and solenoid a failures are common, you might have some debris from the trans repair blown back into the trans or valve body if the last trans failed drastically, you really cant flush out the coolers on these models so debris can work its way back in and nick a seal or hang up or score a valve.
Customer: replied 5 years ago.

Good morning!

Did Line pressure test - shows no ranges too low, BUT - during road test, idle and drive would start out in normal range but shoot up to 190lbs. Pulled car over - shut off- re-started -cont. on road test -readings normal - line pressure 75lbs.- crusing speed- The over/drive neutraled out + press. still at 75 + scanner said it was still in O/D. Pulled car back in shop put car in neutral, pressure went to 190lbs. can hear solonoids clicking on/off. Watching pressure gauge bounce from normal to high readings. Sounds elcectrical to us. Can this be PCM - needing only to be reprogramed (I hope) or replaced?

Customer: replied 5 years ago.
any ideas?
Something is ramping up line pressure and that could be the epc/pressure control solenoid. You would have to see what type of voltage is being sent to it and controled by the pcm from what the graph I sent thats way too high.
Customer: replied 5 years ago.
Didn't get your reply till just now, so we will ck. in the morning. Thank you!
Ok good luck hopefully you can get this resolved quickly and cheaply. Probably debris from when the trans failed prior to rebuilding it worked its way back into the valve body from the trans cooler this does and can happen.
Customer: replied 5 years ago.
Sorry this is taking so long to finish up, But, I'm just wondering why I have NO CODE - when everything is pointing to the PCM needing to be replaced. After all, We never would have gone ahead with the trans. rebuild if we had a code from the beginning telling us it was a computer problem! This is just not right.
Not sure what makes you think the pcm is bad unless it is grounding a circuit for the line pressure solenoid when it shouldnt, you said the line pressure was way too high. Either way PCM faults do not always set a code and anytime a sensor has an issue it doesnt also set a code either,thats where understanding the concern cause/effect process comes into play.
Customer: replied 5 years ago.
You know, I understand what you are saying - but if I can't count on a fault code then aren't I basically telling the customer that I'm going to start throwing parts at it, since I can only guess that it's a sensor or a solenoid gone wrong? And, since those parts did get replaced during the rebuild - what else can it be?

A PCM is cheaper than rebuilding an automatic transaxle. Not everything sets codes, if you are counting on codes to store or turn on a warning light then you wont fix everything that comes in your door. We fix things that set no codes but based on what the issue might by we use our service manuals to diagnose by symptom to get to the root cause of a concern. You don't have to throw parts at anything to fix a concern. I already said the line pressure is spiking way too high, if the pcm isnt commanding the higher line pressure voltage then its not a pcm concern it is most likely a sticking valve or issue in the valve body.

dont forget if you donthit accept, I dont get any credit for helping you. We put a lot of time into this discussion I dont see why we cant this nailed down to either what im suggesting or something else
HDGENE and 3 other Ford Specialists are ready to help you
Customer: replied 5 years ago.
Haven't forgotten you - Unfortunately, everything we have gone back and forth on is just not working to solve the problem. Needless to say,
we have to wind it up and know when we are beaten by something. We have done all the testing again and again and nothing is fixing this trans.
Thank you for your help.