2008 Lexus IS 350FACTORY OEM SERVICE PROCEDURE

Diagnostic Trouble Code Chart

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.

If malfunction code is displayed during DTC check, check the circuit corresponding to the code in the table below Proceed to the information given for the circuit

Multiplex Communication System (BEAN) 

DIAGNOSTIC TROUBLE CODE CHART

DTC Code Detection Item Trouble Area
B1200  MPX Body ECU Stop
  1. Main body ECU RH (Cowl side junction block RH)
  2. Wire harness or connector
B1205  AFS ECU Communication Stop
  1. AFS ECU
  2. Wire harness or connector
B1206  P/W Master Switch Communication Stop
  1. Multiplex network master switch
  2. Wire harness or connector
B1207  Smart ECU Stop
  1. Certification ECU (Smart key ECU assembly)
  2. Wire harness or connector
B1208  Passenger Side Outer Mirror ECU
  1. Outer mirror control ECU RH
  2. Wire harness or connector
B1209  Driver Side Outer Mirror
  1. Outer mirror control ECU LH
  2. Wire harness or connector
B1210  Power ECU Stop
  1. Power source control ECU
  2. Wire harness or connector
B1213  Tilt and Telescopic ECU Communication Stop
  1. Multiplex tilt and telescopic ECU
  2. Wire harness or connector
B1214  Short to B+ in Door System Communication Bus Malfunction
  1. Main body ECU RH (Cowl side junction block RH)
  2. Gateway ECU
  3. Multiplex tilt and telescopic ECU
  4. Windshield wiper switch
  5. Multiplex network switch (Front RH)
  6. Multiplex network master switch
  7. Certification ECU (Smart key ECU assembly)
  8. Power source control ECU
  9. Multiplex network switch (Rear LH)
  10. Front power seat switch RH (Position control ECU)
  11. Front power seat switch LH (Position control ECU)
  12. Multiplex network switch (Rear RH)
  13. Main body ECU LH (Cowl side junction block LH)
  14. Outer mirror control ECU RH
  15. Outer mirror control ECU LH
  16. Front controller (Engine room relay block No 2)
  17. Overhead junction block
  18. Rain sensor
  19. Sliding roof control ECU*1
  20. Wire harness or connector
B1215  Short to GND in Door System Communication Bus Malfunction
  1. Main body ECU RH (Cowl side junction block RH)
  2. Gateway ECU
  3. Multiplex tilt and telescopic ECU
  4. Windshield wiper switch
  5. Multiplex network switch (Front RH)
  6. Multiplex network master switch
  7. Certification ECU (Smart key ECU assembly)
  8. Power source control ECU
  9. Multiplex network switch (Rear LH)
  10. Front power seat switch RH (Position control ECU)
  11. Front power seat switch LH (Position control ECU)
  12. Multiplex network switch (Rear RH)
  13. Main body ECU LH (Cowl side junction block LH)
  14. Outer mirror control ECU RH
  15. Outer mirror control ECU LH
  16. Front controller (Engine room relay block No 2)
  17. Overhead junction block
  18. Rain sensor
  19. Sliding roof control ECU*1
  20. Wire harness or connector
B1247  Tire Pressure Monitor Receiver Communication Stop
  1. Tire pressure warning ECU and receiver
  2. Wire harness or connector
B1248  AVC-LAN Communication Impossible
  1. AVC-LAN (Radio receiver assembly or multi-display assembly)
  2. Wire harness or connector
B1262  A/C ECU Communication Stop
  1. A/C amplifier
  2. Wire harness or connector
B1266  Short to B+ in Instrument Panel System Communication Bus Malfunction
  1. Gateway ECU
  2. A/C amplifier
  3. AFS ECU
  4. Clearance warning ECU
  5. Combination meter
  6. Tire pressure warning ECU and receiver
  7. Wire harness or connector
B1267  Short to GND in Instrument Panel System Communication Bus Malfunction
  1. Gateway ECU
  2. A/C amplifier
  3. AFS ECU
  4. Clearance warning ECU
  5. Combination meter
  6. Tire pressure warning ECU and receiver
  7. Wire harness or connector
B1271  Combination Meter ECU Communication Stop
  1. Combination meter
  2. Wire harness or connector
B1272  Power Seat ECU Communication Stop
  1. Front power seat switch LH (Position control ECU)
  2. Wire harness or connector
B1273 *1 Sliding Roof ECU Communication Stop
  1. Sliding roof control ECU
  2. Wire harness or connector
B1278  Combination Switch ECU Communication Stop
  1. Windshield wiper switch
  2. Wire harness or connector
B1279  Rain Sensor Communication Stop
  1. Rain sensor
  2. Wire harness or connector
B1280  Left Side Junction Block ECU Communication Stop
  1. Main body ECU LH (Cowl side junction block LH)
  2. Wire harness or connector
B1289  Passenger Seat ECU Communication Stop
  1. Front power seat switch RH
  2. Wire harness or connector
B1296  Front Light ECU Communication Stop
  1. Front controller (Engine room relay block No 2)
  2. Wire harness or connector
B1297  Clearance Sonar ECU Communication Stop
  1. Clearance warning ECU
  2. Wire harness connector
If "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTCs (B1200, B1206, B1207, B1208, B1209, B1210, B1213, B1272, B1273, B1278, B1279, B1280, B1289 and B1296), please repair the "+B of GND short malfunction of communication bus" DTCs first.
If "+B of GND short malfunction of communication bus" DTCs (B1266 and B1267)are detected at the same time as "communication stop" DTCs (B1205, B1247, B1262, B1271 and B1297), please repair the "+B or GND short malfunction of communication bus "DTCs first
HINT.
*1 w/ Sliding Roof
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.