Tech notesUsually, the problem is poor harness ground connection.
There is a service bulletin for the following Nissan models with U1000 code:
- 2002-2006 Nissan Maxima
- 2004-2006 Nissan Titan
- 2004-2006 Nissan Armada
- 2002-2006 Nissan Sentra
- 2005-2006 Nissan Frontier
- 2002-2006 Nissan Altima
- 2005-2006 Nissan Xterra
- 2005-2006 Nissan Pathfinder
- 2004-2006 Nissan Quest
- 2003-2006 Nissan 350Z
- 2003-2006 Nissan Murano
Nissan Factory Service Bulletin Code U1000
Service bulletin suggests cleaning engine and body harness ground connection to repair the problem.
- Clean/re-tighten ECM ground connections.
- Clean/re-tighten negative battery cable body connection and battery post connection.
- If needed, clean and ensure good contact between the steering member assembly and the left side instrument stay assembly.
When is the code detected?When ECM is not transmitting or receiving CAN communication signal of OBD (emission related diagnosis) for 2 seconds or more.
U1000 Nissan DescriptionCAN (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.