LIN Bus A Communication Performance
2003-2009 Toyota 4Runner 4.7L V8
Description
Communication on LIN bus A is degraded. LIN buses connect lower-priority subsystems like seat modules, rain sensors, and mirror controls.
Symptoms
- Seat adjustment issues
- Rain sensor not responding
- Auto-dimming mirror malfunction
- Intermittent accessory faults
Common Causes
- LIN bus wiring issue
- LIN master module fault
- LIN slave device failure
- Wiring resistance too high
Diagnostic Steps
- Check LIN bus voltage (typically 0-12V)
- Test LIN master module
- Inspect LIN wiring for high resistance
- Check LIN slave device responses
Repair Notes
LIN bus operates at lower speeds. Check wiring resistance and master module.
Related Codes
Other Network Codes
- U0001High Speed CAN Communication Bus
- U0001High Speed CAN Communication Bus
- U0002High Speed CAN Communication Bus Performance
- U0002High Speed CAN Communication Bus Performance
- U0003High Speed CAN Communication Bus (+) Open
- U0003High Speed CAN Communication Bus (+) Open
- U0004High Speed CAN Communication Bus (+) Low
- U0004High Speed CAN Communication Bus (+) Low
- U0005High Speed CAN Communication Bus (+) High
- U0005High Speed CAN Communication Bus (+) High
U0037 on Other Vehicles
Toyota 4Runner
2003-2009 4.0L V6
Toyota 4Runner
2010-2024 4.0L V6
Toyota 86
2017-2020 2.0L H4
Toyota Alphard
2023-2025 2.4L I4 Turbo T24A-FTS
Toyota Alphard
2023-2025 2.5L I4 Hybrid A25A-FXS
Toyota Altezza
1998-2005 2.0L I4 3S-GE BEAMS
Toyota Altezza
1998-2005 2.0L I6 1G-FE
Toyota Aqua
2011-2021 1.5L I4 Hybrid 1NZ-FXE
Common Questions
What does code U0037 mean on a 2003-2009 Toyota 4Runner?
U0037 stands for "LIN Bus A Communication Performance". Communication on LIN bus A is degraded. LIN buses connect lower-priority subsystems like seat modules, rain sensors, and mirror controls.
What are the symptoms of U0037 on a Toyota 4Runner?
Common symptoms of U0037 include: Seat adjustment issues, Rain sensor not responding, Auto-dimming mirror malfunction, Intermittent accessory faults.
What causes U0037 on a 2003-2009 Toyota 4Runner?
Common causes of U0037 include: LIN bus wiring issue, LIN master module fault, LIN slave device failure, Wiring resistance too high.