Lexus IS250 · Service Manual COMMUNICATION SYSTEM

B1214

Diagnostic trouble codes

DESCRIPTION

  1. When a +B short circuit or body ground short circuit is detected on the door system communication bus (BEAN), BEAN is disabled and a DTC is output.
DTC No.
 DTC Detection Condition
 Trouble Area
B1214
 Door system communication circuit and +B battery system short
  1. Main body ECU RH (cowl side J/B RH)
  2. Gateway ECU
  3. Windshield wiper switch
  4. Power window master switch
  5. Certification ECU
  6. Power source control ECU
  7. Main body ECU LH (cowl side J/B LH)
  8. Front controller
  9. Wire harness
B1215
 Door system communication circuit and body ground short
  1. Main body ECU RH (cowl side J/B RH)
  2. Gateway ECU
  3. Windshield wiper switch
  4. Power window master switch
  5. Certification ECU
  6. Power source control ECU
  7. Main body ECU LH (cowl side J/B LH)
  8. Front controller
  9. Wire harness

WIRING DIAGRAM

B131087E01
B133221E01

INSPECTION PROCEDURE


1. CHECK DIAGNOSTIC TROUBLE CODE (A ECU)

  1. Disconnect the A ECU connector and check for DTCs B1214 and B1215.B079627E08

    OK:
    Neither DTC B1214 nor DTC B1215 is output.

    NOTICE:
    Reconnect the connector before starting the next check.

    HINT:
    1. The A ECU in the door system bus represents the main body ECU RH (cowl side J/B RH).
    2. If the result is as specified, the disconnected A ECU (main body ECU RH (cowl side J/B RH)) is malfunctioning.



 OK
REPLACE A ECU
NG


Go to step 3

2. CHECK DIAGNOSTIC TROUBLE CODE (B ECU)

  1. Disconnect the A ECU and B ECU connectors and check for DTCs B1214 and B1215.B079628E12

    OK:
    Neither DTC B1214 nor DTC B1215 is output.

    NOTICE:
    Disconnect the connectors one by one. Reconnect the connectors before starting the next check.

    HINT:
    1. Remove the B ECUs in the following order:
      1. Power window master switch
      2. Certification ECU
      3. Power source control ECU
      4. Main body ECU LH (cowl side J/B LH)
      5. Front controller
    1. If the result is as specified, the disconnected B ECU (one of the ECUs from the above list) or the wire harness between the A ECU and B ECU is malfunctioning.
    2. After the DTC is cleared, proceed to the next step.



 NG
Go to step 4
OK


Go to step 4

3. CHECK WIRE HARNESS BETWEEN A ECU AND B ECU

  1. Disconnect the B ECU connector and check for DTCs B1214 and B1215.B079912E08

    OK:
    Neither DTC B1214 nor DTC B1215 is output.

    NOTICE:
    Reconnect the connector before starting the next check.

    HINT:
    1. If the result is as specified, the wire harness between the A ECU and B ECU is functioning normally but the disconnected B ECU is malfunctioning.



 NG
REPAIR OR REPLACE WIRE HARNESS BETWEEN A ECU AND B ECU
OK

REPLACE B ECU

4. CHECK DIAGNOSTIC TROUBLE CODE (C ECU)

  1. Disconnect the B ECU and C ECU connectors and check for DTCs B1214 and B1215.B079630E07

    OK:
    Neither DTC B1214 nor DTC B1215 is output.

    NOTICE:
    Disconnect the connectors one by one. Reconnect the connectors before starting the next check.

    HINT:
    1. The C ECU in the door system bus represents the windshield wiper switch.
    2. If the result is as specified, the disconnected C ECU (windshield wiper switch) or the wire harness between the B ECU and C ECU is malfunctioning.



 NG
Go to step 6
OK


Go to step 6

5. CHECK WIRE HARNESS BETWEEN B ECU AND C ECU

  1. Disconnect the C ECU connector and check for DTCs B1214 and B1215.B079631E07

    OK:
    Neither DTC B1214 nor DTC B1215 is output.

    NOTICE:
    Reconnect the connector before starting the next check.

    HINT:
    If the result is as specified, the wire harness between the B ECU and C ECU is functioning normally but the disconnected C ECU is malfunctioning.



 NG
REPAIR OR REPLACE WIRE HARNESS BETWEEN B ECU AND C ECU
OK

REPLACE C ECU

6. CHECK WIRE HARNESS BETWEEN GATEWAY ECU AND A ECU OR C ECU

  1. Check for a short-circuit in +B or body ground.B079632E06

    1. Disconnect the A ECU, C ECU and gateway ECU connectors.

    2. Measure the voltage and resistance of the wire harness side connectors.

      Standard voltage:
      Tester Connection
      		 Specified Condition
      A ECU connector/gateway ECU connector - Body ground
      		 Below 1 V
      C ECU connector/gateway ECU connector - Body ground
      		 Below 1 V


      Standard resistance:
      Tester Connection
      		 Specified Condition
      A ECU connector/gateway ECU connector - Body ground
      		 10 kΩ or higher
      C ECU connector/gateway ECU connector - Body ground
      		 10 kΩ or higher

      HINT:
      1. The A ECU in the door system bus represents the main body ECU RH (cowl side J/B RH).
      2. The C ECU in the door system bus represents the windshield wiper switch.



 NG
REPAIR OR REPLACE WIRE HARNESS BETWEEN GATEWAY ECU AND A ECU OR C ECU
OK

REPLACE GATEWAY ECU


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