4WD Light and No 4WD

[nickelghandi]

Hello all,

I have been with this issue and the shop since they replaced my transmission. After the replacement, my 4WD light would come on intermittently and the lights indicating which drive mode I was in would go out. This usually happened on long highway trips and was difficult for the shop to replicate. It also was fixable by shifting from 2WD to Auto and back a couple times or it would just go away on its own while driving or on the next restart.

Then I noticed it once in 4WD. When it occurs, it moves shifts back to 2WD and 4WD is unusable until the error clears itself once again.

It has not yet happened in 4 Lo, and it won't because I won't use 4 Lo now that I am aware that it tries to switch back to 2WD. Imagine if I were in drive in 4 Lo and it tried to switch back...

As of 3/10/2018, the light came on and is constantly on. I have no 4WD.

Before, I was able to run the diagnostic and it would blink some random code that did not make sense with other codes and then clear itself up for a while. Now, I can neither read the code nor clear the code.

Every time I have taken it to the shop (which is where it has been more than in my driveway since the transmission replacement) I have them try to diagnose this to no avail.

I do need a Universal joint on the front drive shaft, and my shift lock solenoid (thing that lets you shift when you press the brake) does not work, but I do not think those are related.

I have seen the older threads, and tried their fixes to no avail. The transmission fluid is fine as is the transfer case and differential fluid. I have no leaks.

I am thinking possibly the TCM or even an ABS sensor, but I don't know and don't have the equipment to diagnose. I would take it back to the shop, but I have given them almost $500 in diagnosis at this point and they have returned nothing. They are an extremely reputable shop and have lots of experience with Nissans. I also know the owner and head technician personally so I doubt foul play or incompetence.

Is it worth it to take to the dealer or will they (and this seems likely from previous experience) just tell me some ridiculous repair that costs like $3,000 to do and won't even fix the issue?

I am at a loss and considering selling this vehicle because it has seen less than 2000 miles since August 2016 when the transmission failed and was replaced because of other issues mentioned in other threads and this 4WD issue.

Anyone had this issue before? How did you fix it? Anything guys...

[Rockwood]

I think I would take it to the dealer and have them give you a diagnostic. Have them give you all the trouble codes. The Consult II can read those trouble codes, and if necessary, do a diagnostic on the body control module and the transfer control module.

I would tell them you want the diagnostic and repair estimate so you can decide what to do with the vehicle.

At least that way you have a starting point. Kinda shootin in the dark with no codes.

[nickelghandi]

Thanks for the reply. That is what I feared. I am planning a trip to the dealership now.

I hate that I cannot get it to display any codes. It is as if it isn't responding at all. If I do the procedure it will blink twice and the 4WD light will shut off until the next startup.

[brickbox]

Just a suggestion.....not necessarily the best path. But, you could try swapping out the TCM with a used one at a local JY/ebay. It would probably still be cheaper than going to the dealership for diagnostics. If it fixes the problem, great. If not, worst case scenario you can return the used unit and then take it to the dealership?

[nickelghandi]

Good idea brickbox.

I actually just looked at them before replying. Most of them specify that they are for models without VDC. Now I am wondering if the shop that replaced my transmission replaced the TCM with one without VDC and now possibly the ECU and TCM aren't communicating properly. Might be why I cannot get it to flash codes anymore either. It might be worth one more $75 diagnostic fee to have it checked out.