well my 4wd switch is not kicking the truck into 4x4 mode...i have swapped out switch and still didnt work...i called the dealership and they are thinking the PCM...what i want to know is can i do some rewiring to bypass the pcm so the switch directly controls what ever kicks into 4hi and 4lo. truck out of warrantee so wanting to save some mula.

what ya all think?

thanks

 

Does your light illuminate on the dash saying 4x4? If not it might be the part on the side of the transfer case that switches the transfer case into 4x4. If the light does come on but no 4x4, it could be something in the IWE system not letting the vacuum release to the hubs, maybe the IWE solenoid. I would check out those things before going the PCM route.

But if it is the PCM, i think the PCM is covered under the federal emmisions warranty for 70-80,000 miles. you still in that range?

 

I'm thinking the transfer case solenoid/motor...the PCM is a big jump. Tap on the motor with a hammer and see if it engages.

 

Yes that is what i was getting at, the solenoid/motor on the side of the transfer case. But if that is working and still no 4x4, you IWE solenoid might not be working and releasing the vacuum. I would bet its one of those problems and not the PCM.

 

I might be wrong, but I'm fairly sure he'd still get the light on the dash if it was IWE Solenoid. You also tend to get some other symptoms with bad IWE's or IWE Solenoid...usually a grinding noise.

 

when i start the truck the two 4wd lights blink a couple of times and then turn off...i will turn the switch for 4HI and nada...same on 4LO...

 

That's normal, all of our trucks do that at start up. Seriously, tap on the motor.

 

that not working...i dont hear the usual click when you turn the switch...i do not think it is transmitting electically what ever it does to engage 4hi and 4lo

 

I'd break out my multimeter and see if the motor is getting a current when the selector is switched. I've been perusing this website for a long time and I've never heard of a PCM problem involving the 4x4 selector or a bad switch. When it comes engaging the 4x4 it's always the motor (it could be bad) or the IWE solenoid...but there's always a first.

Do you have any DTC's showing up? If it does involve the PCM I would think it would throw a code...

 

no codes being thrown...i will pull my switch and do testing myself to see if your results are the same as mine

 

take a hammer and hit that motor on the t-case...sounds stupid, but just try it

 

I wasnt sure, i thought i read somewhere that if the motor on the transfer case wasnt working than the light wouldnt come on, or something like that. I have also seen where the IWE solenoid goes back in a state where is always has the hubs unlocked, not letting them lock in. Just a thought.

 

Most likely tranfer case shift motor. Hit the thing with a hammer and if it engages, it's the motor. Trust us, it works. Of course you can get the old multimeter out and see if it's getting juice. That'll work too. It happened on my 06 and that's what the tech did to check it ( the hammer routine). If only we could still get manual locking hubs and tranfer case on an F150.

Greg B

 

X2 What he said.. LOL

I had the same problem; however, I was able to narrow it down to the electric shift motor with 100% confidence because the wires going to the plug on it were completely severed, looked like a bear mauled it. Replaced it and problem solved. Here's the thread for it:
https://www.ford-trucks.com/forums/7...-problems.html

 

i wonder if i can rewire directly to the solenoid to get the 4hi and 4 ho up and running.