B1215

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1214: Short to B+ in Door System Communication Bus Malfunction

DTC B1214 - Short to B+ in Door System Communication Bus Malfunction

DTC B1215 - Short to GND in Door System Communication Bus Malfunction

DESCRIPTION
- B1214 and B1215 are output when +B and the body ground is short-circuited on the communication bus. Detecting this condition disables all the BEAN communication and outputs some DTCs.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK DIAGNOSTIC TROUBLE CODE (A ECU)
(a) Check whether the output of the DTC stops when the A ECU connector is disconnected.




NOTE: Disconnect the connectors in the operational sequence, and start the next step after the connector in connected.
HINT: In this case, the A ECU in the represents the back door ECU.

OK:
When the output of the DTC stops, the disconnected A ECU is abnormal.
OK -- REPLACE A ECU

NG -- Continue to next step.

2. CHECK DIAGNOSTIC TROUBLE CODE (B ECU)
(a) Check whether the output of the DTC stops when the B ECU connector is disconnected.





OK:
Neither DTC B1214 nor DTC B1215 is output.
NOTE: Disconnect the connectors in the operational sequence, and start the next step after the connector in connected.
HINT: In this case, the B ECU in the represents the theft deterrent ECU.

OK:
When the output of the DTC stops, the disconnected B ECU is abnormal.
OK -- REPLACE B ECU

NG -- Continue to next step.

3. CHECK WIRE HARNESS BETWEEN BODY ECU AND A ECU OR B ECU
(a) Disconnect the A ECU, B ECU and body ECU connectors.
(b) Check the wire harness (MPX line) between the A ECU, B ECU and body ECU.





(1) Turn the ignition switch to ON.
(2) Check the voltage between the wire harness (MPX line) and body ground.
Standard voltage:





If the output voltage is not Below 1V, the wire harness (MPX line) may be short-circuited with +B.
(3) Check the resistance of the wire harness (MPX lines) and body ground.
Standard resistance:





If there is Below 1 Ohms, the wire harness (MPX line) and body ground may be short-circuited with the body ground.

NG -- REPAIR OR REPLACE WIRE HARNESS BETWEEN BODY ECU AND A ECU OR B ECU
OK -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY