i know this has been asked a thousand times

[crossbow68]

my son's 02 explorer 4.0l trans is giving a p0745 code and od off is flashing. seems to shift fine but freewheels in drive with od switch turned off, rpms drop and it will coast until you bring rpms back up but turn od back on and it acts fine, the light is flashing as this is being done. it will reset itself after restart.does have a harsh down shift to second or first also. you guys have any ideas? thanks in advance

 

[imp]

@crossbow68
Indicates Pressure Control Solenoid malfunction. Inside Transmission. Part of the Solenoid Module. I would check the PCS coil resistance, then if OK, test it's function with 12V applied. Likely a failed solenoid. imp

 

[crossbow68]

thanks imp! but now, how do i go about checking it and would i need to replace the whole module

 

[imp]

thanks imp! but now, how do i go about checking it and would i need to replace the whole module

@crossbow68
It depends on your electrical background. If you understand basic Electric Theory, and have an Ohmmeter, the starting point is to begin at the appropriate PCM (computer) connector, disconnected, and measure the electrical resistance between that point and the Solenoid's B+ conection, at the transmission case connector. If the Solenoid's coil resistance checks out OK, then a low-resistance to ground ( a "short"), would be looked for. If these electrical checks prove out OK, then mechanical failure of the Solenoid itself becomes suspected. The PCM ( computer) cannot discern between solenoid electrical failure or mechanical failure, so it throws an electrical "code". Up to us to determine which it is, if either. Digital trouble codes are not infallible, due to the myriad of possible causes of failure.

If what I'm saying is basically "Greek" to you, I cannot help you more, except to say that a reliable and knowledgeable shop will be needed. OTOH, if your electrical knowledge is such that you follow this, then the solution might be resolved. Regarding the Solenoid Module, yes, they are all 8 permanently mounted upon a backing plate, and given one bad, the entire bunch get replaced. In some ways, this is not a bad thing, even though I disagree with the design, as the solenoids are a much used part of the system, and given one gone bad, replacing them all ain't a terribly bad idea, though it wastes money. imp

 

[crossbow68]

yeah, i know something about electrical systems , ase certified, just need to know which connectors to pin out or a wiring diagram

 

[swshawaii]

^ Maybe here?

http://www.bbbind.com/free_tsb.html

 

[crossbow68]

thanks swshawaii !!!

 

[imp]

^ Maybe here?

http://www.bbbind.com/free_tsb.html

@swshawaii
But my PC would not open the link. Maybe Bad Day at Blackrock? imp

 

[swshawaii]

^ imp, just register.
BBB Industries - TSB's & Wiring Diagrams

By clicking “Submit”, you agree to receive periodic e-mails and communications from BBB Industries and its partners. Your information will be held in strict confidence. You may stop receiving communications at any time by replying to e-mails with the word “stop” in the subject line.

 

[imp]

^ imp, just register.
BBB Industries - TSB's & Wiring Diagrams

@swshawaii
This is maddening! When I click on the link above, I get a white page overr which is superimposed "Internet Explorer has stopped working. I.E. i searching for a solution to the problem", with usual green bar moving across, then a big red "X" appears stating "BBB....cannot be connected. imp

 

[crossbow68]

opened right up for me, i still have tab open from yesterday

 

[swshawaii]

This is maddening! When I click on the link above, I get a white page overr which is superimposed "Internet Explorer has stopped working. I.E. i searching for a solution to the problem", with usual green bar moving across, then a big red "X" appears stating "BBB....cannot be connected. imp

Appreciate your frankness. If you are computer illiterate, then I am illiterate squared! Right now, am lucky to be here at all. Attemting to return here, an immovable flag asking for some kind of registration blocks the login box, had to try 6 times, almost gave up. Tried all 3 of my browsers. So, if you do not hear from me, it's 'cause I can't get in. imp

imp, you obviously have computer issues. Not sure, but have you tried Google Chrome?

Maybe start a thread in the computer sub forum linked below?
[URL]https://www.explorerforum.com/forums/index.php?forums/exploring-computers.44/[/URL]

 

[imp]

imp, you obviously have computer issues. Not sure, but have you tried Google Chrome?

Maybe start a thread in the computer sub forum linked below?
[URL]https://www.explorerforum.com/forums/index.php?forums/exploring-computers.44/[/URL]

@swshawaii
I tried Chrome and Mozilla also. Will check link above. imp

 

[TechGuru]

I heard to never apply 12V directly to any of the solenoids that they are modulated and not designed for constant voltage...

 

[imp]

I heard to never apply 12V directly to any of the solenoids that they are modulated and not designed for constant voltage...

@TechGuru
Right out of the Ford 2004 Gas Engines Powertrain Control/Emissions Diagnosis Service Manual. If one consults the wiring diagrams, it is obvious that the transmission solenoids are turned on and off by PCM by completing their coils' ground circuit. The other end of the coil is connected directly to "Hot in Run or Start", via a fuse. Therefore, even though I have heard the same thing you have, the only "modulation" of the solenoids possible would be to turn power on and off to them repeatedly and quickly. Illogical, but possible. The Shop Manual lists solenoids which are called "modulated", without consulting back, I believe TCC, and Pressure Control are such. Given the D.C. resistance called out for the coils, in diagnostic troubleshooting, it seems doubtful too that testing for movement by listening for their "click", or actually measuring current draw, would be likely to harm them. But, OTOH, what do I know?? imp

 

[TechGuru]

@TechGuru
Right out of the Ford 2004 Gas Engines Powertrain Control/Emissions Diagnosis Service Manual. If one consults the wiring diagrams, it is obvious that the transmission solenoids are turned on and off by PCM by completing their coils' ground circuit. The other end of the coil is connected directly to "Hot in Run or Start", via a fuse. Therefore, even though I have heard the same thing you have, the only "modulation" of the solenoids possible would be to turn power on and off to them repeatedly and quickly. Illogical, but possible. The Shop Manual lists solenoids which are called "modulated", without consulting back, I believe TCC, and Pressure Control are such. Given the D.C. resistance called out for the coils, in diagnostic troubleshooting, it seems doubtful too that testing for movement by listening for their "click", or actually measuring current draw, would be likely to harm them. But, OTOH, what do I know?? imp

You're right I think it may only apply to the pressure control solenoids and not the shift and TCC solenoids.

 

[shucker1]

If you really thought about it you could use a 1 AMP 12 Volt battery charger as you power source. That way current, which produces heat and causes failure of winding insulation, is limited.

Unlike a 12 Volt battery which is designed to put out 300 AMPS in one shot.

I would rather be safe then smell that wondrous aroma of "Burnt Insulation" .