U1000 nissan
OBD2 Error Codes

U1000 Nissan GM Code - CAN Communication Line - Signal Malfunction

26.05.2022 /

Usually the problem with the U1000 on Nissan is a bad wiring ground. A service bulletin exists for the following Nissan models with code U1000: 

  • – Nissan Maxima 2002-2006 
  • – Nissan Titan 2004-2006. 
  • – Nissan Armada 2004-2006. 
  • – Nissan Sentra 2002-2006. 
  • – Nissan Frontier 2005-2006 .
  • – Nissan Xterra 2005-2006 g. 
  • – Nissan Pathfinder 2005-2006. 
  • – Nissan Quest 2004-2006. - 2003-2006
  • - Nissan 350Z - 2003-2006. 

Solve the problem of – Clean/tighten the ECM ground connections. – Clean / retighten the negative battery cable housing connection and the battery connection. – If necessary, clean and check for good contact between steering column and left leg assembly. What does it mean?

Nissan U1000
Nissan U1000

OBD-II Trouble Code - U1000 - Data Sheet

GM: Class 2 communication failure condition Infiniti: CAN communication line - signal failure Isuzu: Link ID class 2 not found Nissan: CAN communication circuit

CAN (Controller Area Network) is a serial communication line for real-time applications. It is an airborne multiplex link with high data rate and excellent error detection capability. There are many electronic control units installed on the vehicle, and each control unit exchanges information and communicates with other control units during operation (not independent). With CAN communication, the control units are connected by two communication lines (CAN H line, CAN L line), which provide a high speed of information transfer with fewer connections.

Each control unit transmits/receives data, but selectively reads only the requested data.

What does code U1000 mean on Nissan?

This is the manufacturer's network code. Specific troubleshooting steps will vary depending on the vehicle.

Malfunction code U1000 - this is a code for a specific car, which is mainly found on cars Chevrolet, GMC and Nissan. This refers to "class 2 communication failure". Typically, this code precedes an additional code that identifies the module or fault area. The second code may be generic or vehicle specific.

The electronic control unit (ECU), which is the vehicle's interrupted computer, cannot communicate with a module or a series of modules. A module is simply a device that, when ordered to do so, performs an action or movement superbly.

The ECU transmits its commands to the modules via a network of "CAN-bus" (controller local area network) wires, usually located under the carpet. The vehicle has at least two CAN bus networks. Each CAN bus is connected to many different modules throughout the vehicle.

The CAN bus communication network was developed by Robert Bosch and began appearing in cars in 2003. Since 2008, all vehicles have been equipped with CAN bus networks.

The CAN bus communication network provides extremely high speed communication with the ECM and its associated modules, making them interactive. Each module has its own identification code and sends binary coded signals to the ECM.

A prefix of 0 or 1 determines the urgency or priority scale of the signal. 0 is urgent and needs an immediate response, while 1 is less urgent and can rotate until traffic decreases. The following module activity codes will be represented as binary bits visible on the oscilloscope as a square sine wave, with the wave height being the medium by which the ECM interpolates the signal and determines the strategy for the module.

Symptoms of error U1000

Possible Causes of Error U1000

The reason this code appears depends on the vehicle. The second code identifies the defective part or area in which the malfunction occurred. The code is so specific that technical service bulletins (TSBs) must be checked not only for the vehicle brand, but also for the specific model and available options for an accurate assessment.

I have tested several Nissan vehicles with code U1000, which were parked separately. No problems were found on any of the systems, but the code survived. The code was simply ignored, which did not indicate the absence of any driving or operational problems.

Some vehicles recommend that you replace the ECM as this is the main reason this code appears on this vehicle. Others can cause the variable speed wiper motor to fail. In the case of one known Nissan TSB, the fix is ​​to clean and tighten the ground wiring connections.

The ECM and modules go to sleep when the key is off to reduce the load on the battery. Most modules go to sleep within a few seconds or minutes after shutting down. The time is preset, and when the ECM issues a command to sleep, if the device does not turn off within 5 seconds after the command, even 1 extra second will set this code.

Possible reasons for the code U1000 NISSAN:

The cost of diagnosing code U1000 NISSAN

The cost of diagnosing the code U1000 NISSAN is 1,0 hour of labor. The cost of auto repair work depends on the location, make and model of your vehicle, and even your engine type. Most body shops charge between $30 and $150 an hour.

Where is the U1000 sensor located?

U1000 sensor
Where is the U1000 sensor

The image above shows a simplified representation of how the CAN bus system connects many control modules and systems in a typical Nissan application. In practice, a typical CAN bus serial communication system consists of several kilometers of wiring, thousands of circuits, and more than a thousand connections that tie several dozen control modules together. For this reason, it is almost always easier and more cost effective to seek professional help when dealing with CAN bus related codes.

U1000 Code - how to fix?

All communication over the CAN bus requires a good ground, no short circuit continuity, no resistance that can cause voltage drops, and good components.

  1. Access all Technical Service Bulletins (TSB) related to code U1000 and any additional codes for your specific model and option group.
  2. Use the service manual in conjunction with the TSB to identify the problem area or module.
  3. Learn how to access the failed module.
  4. Disconnect the module to isolate it from the harness and CAN bus connector.
  5. Using a voltmeter, check the CAN bus harness and connector for shorts or open circuits.
  6. Explore a wide range of regulation applications using a motor control unit or module to make decisions.

U1000 Nissan Information for specific Nissan models

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