For Shop Owners

U1000 INFINITI - CAN Communication Line - Signal Malfunction

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3 What does this mean?

Possible causes

  • Controller Area Network (CAN) communication harness is open or shorted
  • Faulty Engine Control Module (ECM)
  • Poor harness ground connection.
What does this mean?

Tech notes

There is a factory service bulletin for the following Infiniti models:
- 2002-2004 Infiniti I35
- 2002-2006 Infiniti Q45
- 2004-2006 Infiniti QX56
- 2003-2006 Infiniti FX
- 2003-2006 Infiniti G35
- 2003-2004 Infiniti M45
- 2006 Infiniti M
Infiniti 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.

There is another Infiniti service bulletin with tips to diagnose the U1000 code:
Infiniti Service Bulletin Code U1000 Diagnostic Tips and Guidelines
What does this mean?