Sorry for the lengthy post, but I have been trying for awhile now to fix it. I am having trouble with my 4wd, but it is a little different than most of the threads.

In Oct, ’19 I bought a 2007 Dodge 1500 4.7L 6 speed 4X4, when I bought it the 4wd did not work, but the previous owner said that it was working when he had it to the dealer in June, ’19. The dealer replaced the front axle actuator.

Nov, ’19 I change out the front axle actuator, thinking that it may be bad, but it did not change anything. I still had the same issue, so I put the dealer installed one back on.

Dec, ’19 I changed out the transfer case shift motor and it did the same as the old shift motor.

Jan, ’20 I take the truck to the dealer and they say it has a code C1405 and that the truck needs a new TIPM, so I order one and change it out. I did a hard reset on the new TIPM and still the same thing. (I am pretty sure the C1405 code came from me unplugging the transfer case motor to see if the “SERV 4WD” light would come on, and it did.)

Feb, ’20 I contact the dealer and get the trouble shooting guide and the wiring diagram for the TIPM, the transfer case plug, and the front axle actuator. I start trouble shooting all the wiring on the truck. When I test the feedback circuit to the TIMP from the transfer case I have:

3.34VDC in 2wd

4.31VDC in 4wd

1.45VDC in 4wd low

These voltages should be good for the feedback circuit to the TIPM. I then move to the front axle actuator, and I have 12VDC to Ground and 10.1VDC on wire #4 “Front Axle Lock Control” according to these voltages the actuator should work. I have also checked all the wiring from the transfer case plug to the TIPM and from the TIPM to the front axle actuator. It all ohmed out good.

I have since contacted the dealer again, and the tech told me when he had my truck hooked up to the scan tool it did not see the 4wd parameters on the PCM or the transfer case, (I wish he would have told me that sooner).

I am in this to the tune of about $1100 and still no 4WD. Am I missing something? What do I need to do, or try next?

There are a few more minor things I have tried, but this post is already long and these little things didn’t help either.

Thanks for all your help.

 

So is the serv 4wd light on or off ? And are the lights on the indicator on switch showing it in 2wd 4wd or low or are they out ? any codes at all ?
There is a transfer case control module you can research issues about .

When I got my 04 the 4wd did not work , had some weird mode sensor error but I had a really good handheld that could do more than just check engine codes , it can look at many things other than just codes for engine,,, but the indicator on the switch would not light up in 2wd or 4wd or low which was causing the mode sensor error , I replaced everything once including the pcm and checked for proper 5 volts and grounds in all the areas including the transfer case control module and even the mode sensor on the shift motor , but while checking the mode sensor with key on in ignition , I found the 5 volt on plug and using my multimeter , I left one lead on the 5 volts prong on plug and checked it to all the other prongs on that plug including the grounds , now at this point I went thru it while meter was in ohms , but whatever I did caused it my indicator lights to started working and so did the 4wd , it was like resetting a gfi plug in a way , still working a year later , not saying it will help yours as I don't know your problems and its a different year but these trucks share 5 volts an grounds to most sensors even at the pcm shares this , so by jumping the 5 volts thru the plug for mode sensor to all areas including the ground got some sort of reset on mine , cant recommend you doing this as I don't want you to burn something up , just telling you what worked on my truck,,I did also went through the wiring on mode sensor end looking for bad spots and alot of other wiring as well but found nothing until i did the meter testing cured it,,a loose or bad ground can cause issues as well as there are several areas to check for them as well an clean
My truck came with many issues and I changed every sensor an pcm but the 4wd took me to my wits end before I got it working along with a dozen engine codes I finally resolved

 

The "SERV 4WD" light is off, and does not come on until I unplug the Transfer case. The indicator light on the dash are showing 4WD and 4LOW, but they just flash when you are in there range. When in 2wd none of the 4wd lights are on. Does my model year of truck have a transfer case module?

 

Yes I think your has the TCCM but you will need to research some more , also I recommend a good scanner , my mode sensor error does not show up as a p code or with engine light , but my scanner was able to scan the transfer case to show me the error , I take it you changed the selector switch ?

 

My 04 is different than yours in many ways , like the front actuator is different and I dont have a tipm , mine has a ipm and so there are differences , ,,everything I read about yours says actuator , or even the computer may need flashed , so I may not be much help but I think that most rams have the TCCM but you will need to check on that

 

Thanks for the information. I did not however change the selector switch, since the transfer case was shifting properly I didn't think it needed it. I was thinking a re-flash, but I wanted to stop blindly throwing money at it.

 

Yeah its easy to throw money at it to chase things down , selector switch is lighting up , the blinking is because its not engaging so switch is probably ok