1001/1000 Can Comm Circuit

[woldem]

I did the diagnostic test on my 2002 Nissan Altima 2.5S and got codes 1001/1000. When I looked these up, it was "Can Comm Circuit". What the heck is that and is it something I can fix myself? I looked it up on google and didn't find anything. Any help would be appreciated. Thanks.

[xXLoganXx]

Originally Posted by woldem

I did the diagnostic test on my 2002 Nissan Altima 2.5S and got codes 1001/1000. When I looked these up, it was "Can Comm Circuit". What the heck is that and is it something I can fix myself? I looked it up on google and didn't find anything. Any help would be appreciated. Thanks.

DTC U1000, U1001 CAN COMMUNICATION LINE
Description

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex
communication line with high data communication speed and excellent error detection ability. Many electronic
control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.

Possible Cause:
Harness or connectors
(CAN communication line is open or
shorted)

What have you been messing with or did you get this error out of nowhere??

[woldem]

Thanks for replying so fast. I haven't touched anything on the car any time recently. It basically popped out of nowhere. I've cleared out the code a couple times and it comes right back on with the same error.

[woldem]

Do you happen to know where this particular harness or any connectors that may have come loose would be located? I live in Minnesota, so could it be something with the cold? It turned on a couple weeks ago which was about the same time that it got cold here.

[xXLoganXx]

Originally Posted by woldem

Do you happen to know where this particular harness or any connectors that may have come loose would be located? I live in Minnesota, so could it be something with the cold? It turned on a couple weeks ago which was about the same time that it got cold here.

I see that you have a 2.5 right? If so, the CAN lines are connected on the ECU by pins 34 & 33 and then connected to the TCM (Transmission Control Module), pins 5 & 6. They are both located on the underside of the glove box. I wouldn't recommend messing with it if you're not experienced with working on the electrical system. From what I am reading... it seems that the only thing a DIY'er could find that would actually find to fix your problem would be a dangling wire from one of those pins. Other then that... you're gonna have to take it in to Nissan to have a Consult II hooked up to it to pry deeper into the electrical diagnostics. Sorry....

[woldem]

Thanks for the info. I'll see if I can find anything out of the ordinary.

[woldem]

Are there instruction as to how to get to the ECU and TCM under the glove box? Do I end up having to take the glove box off? I haven't gotten under there yet...

[xXLoganXx]

Yes, you will have to take the glove box out. It's not hard to figure out... just pull some trim pieces here and there and it will reveal all the hidden screws along with the obvious ones.

[woldem]

I finally brought my car in to Nissan to have it checked out and it was a bad TCM. They replaced it and it was covered under warranty to 60K. My car has 57K. NICE!!

[Griffin]

old thread but i got these codes recently. they happened to be the positive battery end cables. luckily for me it was a $10 part and easy to install.