Lost Communication - General Bus Timeout
2007-2012 Nissan Altima 2.5L I4
Description
General timeout on the communication bus. Multiple modules are not responding within expected time.
Symptoms
- Multiple systems intermittently offline
- General communication degradation
- Multiple timeout DTCs stored
- Scan tool slow response
Common Causes
- CAN bus overloaded
- Poor bus termination
- Multiple modules with slow response
- Bus wiring degradation
- Power supply instability affecting modules
Diagnostic Steps
- Check bus termination resistance
- Monitor bus load with scope
- Check power supply voltage to modules
- Test for intermittent connections
- Remove aftermarket CAN devices
Repair Notes
Check bus termination and overall bus health. Overloaded buses cause timeouts.
Related Codes
Other Network Codes
- U0001High Speed CAN Communication Bus
- U0002High Speed CAN Communication Bus Performance
- U0003High Speed CAN Communication Bus (+) Open
- U0004High Speed CAN Communication Bus (+) Low
- U0005High Speed CAN Communication Bus (+) High
- U0006High Speed CAN Communication Bus (-) Open
- U0007High Speed CAN Communication Bus (-) Low
- U0008High Speed CAN Communication Bus (-) High
- U0009High Speed CAN Communication Bus Shorted Together
- U0010Medium Speed CAN Communication Bus
U1040 on Other Vehicles
Nissan 200SX
1995-1998 1.6L I4 GA16DE
Nissan 200SX SE-R
1995-1998 2.0L I4 SR20DE
Nissan 240SX
1995-1998 2.4L I4 KA24DE
Nissan 300ZX
1990-1996 3.0L V6 VG30DE
Nissan 300ZX Twin Turbo
1990-1996 3.0L Twin-Turbo V6 VG30DETT
Nissan 350Z
2003-2006 3.5L V6 VQ35DE
Nissan 350Z
2007-2009 3.5L V6 VQ35HR
Nissan 370Z
2009-2020 3.7L V6 VQ37VHR
Common Questions
What does code U1040 mean on a 2007-2012 Nissan Altima?
U1040 stands for "Lost Communication - General Bus Timeout". General timeout on the communication bus. Multiple modules are not responding within expected time.
What are the symptoms of U1040 on a Nissan Altima?
Common symptoms of U1040 include: Multiple systems intermittently offline, General communication degradation, Multiple timeout DTCs stored, Scan tool slow response.
What causes U1040 on a 2007-2012 Nissan Altima?
Common causes of U1040 include: CAN bus overloaded, Poor bus termination, Multiple modules with slow response, Bus wiring degradation, Power supply instability affecting modules.