08 Pathfinder 4WD AT ECM fuse blowing

[jschettini]

I have a 2008 V6 4WD Pathfinder that has started blowing the 10A A/T ECM fuse. This causes the truck to enter limp mode and lights the 4WD warning light on the dash. Does anyone have any experience with this issue and have a fix or work-around? I have already checked the trans fluid and this does not seem to be related to the issue that some had where the radiator leaked into the transmission. Replacing the fuse allows me to start the truck but as soon as I shift into Drive the fuse blows. There is also a SES code of U1000 which is "lost communication with ECM/PCM" which I am assuming is due to the blown fuse.

[jschettini]

Does anyone know if there is anything else on the circuit that is protected by that same fuse? I thought I read somewhere that there is one other connection on that circuit and I would like to check all the simpler (cheaper) things before I have my transmission opened up. Also, any other suggestions on places to check would be greatly appreciated. Thanks.

[rgk]

My suggestion is to check the factory service manuał for your year vehicle, which is conveniently located right here on this site. Check the sticky thread entitled "General Information and FAQ."

[jschettini]

Thanks! I found the FSM and looked at the transmission section. It looks like the control valve/TCM is accessible through the trans fluid pan, so does that mean that the transmission doesn't have to be removed to replace the control valve/TCM? Can you also point me in the right direction to find the right wiring diagram to see what else (if anything) is on that circuit?

[rgk]

I don't know about whether you will be able to remove the control valve, as I'm not familiar with it, but I'm certain the wiring diagram will be somewhere within that FSM. You should also be able to find troubleshooting steps for your particular trouble code. At this point I'd say it's worth a shot to drop the pan.

[rgk]

Per the FSM, page TR-45, U-1000 indicates that your CAN connection line is open or shorted. Seeing as how you're blowing a fuse, I'd say it's shorted. Check the wiring from your transmission and transfer case.

[jschettini]

UPDATE: I do in fact have the dreaded coolant contamination which has killed the transmission. It's in the shop now and work will begin early next week, including the radiator bypass. This is a shame because this is my 4th Nissan vehicle I have really liked all of them.

I filed a claim with NHTSA about it and through some research it appears that it is still under investigation. I know it is a long shot but hopefully somewhere down the road there will be some compensation. If anyone else has had this problem or know someone who has had it please encourage them to take the couple of minutes to file a claim as well. Most of us already know this but the problem is also present in the Frontier and Xterra as well so encourage them to look into this too. The more people who file a complaint the better.

[jschettini]

i meant to include the NHTSA complaint site link. Here it is:
https://www-odi.nhtsa.dot.gov/VehicleCo ... ndex.xhtml

Also, my truck has 127kmi so i am well out Nissan's pathetic "extended warranty" offer.

[rgk]

Dang, that sucks, sorry!