4r100 question/problem

Mopar1973

Mopar1973

New member
So I recently overhaul a 4r100 in an 01 F250 4x4 PSD and its become a bit of a headache. Came in with p0708 and p0713 and had water in the unit, forward and intermediate clutches were smoked and it didn't move. So fast forward...rebuild is done, truck shifts 1-2-3 fine, with the blinking od off light it has no OD and No lockup due to the trans temp sensor code. If you unplug it and let it go into failsafe (4th) it has a good 4th gear. It air-checked before assembly, has all the gears and I have put 2 NEW OEM Ford solenoid packs on this thing so far. With the modis Hooked up, the trans temp sensor (idling in park at operating temp) will read 5deg-8000deg (you read right) and jump back and forth sporadically and anywhere in between. New MLPS and it too throws the same code. Reset computer and am still getting this problem. Clear codes and it will come back instantly. It does have a plethora of other codes but I do not believe they pertain to this problem. Came in with said codes...thoughts on where to start? BTW I did check the harness out...no kinks or exposed wires from what I saw.
 
Fords are notorious for back feeding on the 5 volt side.... Need to check diagrams and see what power and grounds are shared with other sensors. Also have somebody wiggle that harness while monitoring.
 
PCM Codes: p0713, p0475, p0708

GEM/SJB Codes: b1302, b1731, b1352

I disconnected the batterys, drained the capacitor, reset the pcm and these codes immediately come back. Doesn't matter what you do. I don't recall if I mentioned it but this unit had water in it, could it have shorted the solenoid pack and done something with the harness/pcm? The guys that drive the truck denied any water, but the unit was caked in dried mud up to the bellhousing and the clutch material fell off the metal backing like wet paper.
 
So unplug the ebp and clear codes and see if the trans ones come back. That ebp shorted will do all kinds of crazy back feeding.
 
Exhaust Back pressure. Pass side of motor right up front connected to a tube from pass exhaust manifold.
 
unplugged that...tossed p0742 on top of the other 3 pcm codes. They did not come back immediately but they did come back.
 
I'm not finding po742... po472 makes sense.... Plug EBP back in and monitor. should be around 13 and change when start and rev. Next, unplug the connector that controls the turbo warm up valve . Also make sure the lift pump is operating... What is the plethora of other codes and does everything on the cluster seem to be working?
 
it is 472..sorry about that. Post #3 contains the 5 codes it currently stores. Also, my primary concern are the transmission codes. I am positive they are external to the transmission but as to their origins...I have no idea.
 
Right... I thought you said it has more than posted. This issue is not trans related if you put new solenoids and everything in trans.... Deffinetly wiring issue or sensor failure.... It may seem I'm runnin ya around a lil but all t6hose things plus more will cause these problems.... So, back to my last post, have you tried that yet?
 
Everything on the cluster seems to operate properly. Airbag light bottom left corner of the cluster is blinking.
 
Built into turbo pedestal.... Also check the plug that goes to the red and green plastic lines in front of the turbo. That is the exhaust psi regulator. which sends signal to warm up valve.
 
I tried your suggestions and have not had any success...I spoke with ATSG about it and everyone seems to be at the conclusion it is a grounding issue...I plan to splice a ground directly to the frame and see how that goes.
 
I agree with that, except I think it's a 5volt sensor shorting and introducing 12 volts to it.... Missing ground may be also.
 
Its looking like pins #7 and 8 are for the TFT. #7 is the 5v input and #8 is the signal return...#8 is what I should be splicing into/grounding correct?
 
I don't think so.... Tryin to find in all data.... Going to have to pull out the ford book. I am assuming that the sensor is internally grounded through itself to the case. Need to check voltage key on with dvom.
 
Bump! Bought a multimeter and went to town. Ohm it out at idle and it reads .049 ohms at the most and then when the temp spikes on the modis it goes to 0 ohms. If I probe the #8 orange/black wire and ground it for voltage with the key on I am supposed to get 5volts and it jumps between 2.5-4v at the most and never stays consistent. Tried a couple chassis grounds to make sure it wasn't me picking a bad spot. Whats weird is the modis says it is getting a consistent 5.12 volts? PCM bad maybe? Probing at PCM terminal #37 next to see if it could possibly be a bad wire.
 
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