PROCEDURES FOR DETERMINING LOCATION OF MALFUNCTION[MULTIPLEX COMMUNICATION SYSTEM (L3)]


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System Wiring Diagram

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PCM

1.  Using the M-MDS, verify that the DTC U0121 is displayed. (See DTC TABLE[MULTIPLEX COMMUNICATION SYSTEM (L3)].)

2.  Referring to the following table, determine the malfunctioning part of the CAN system.

Note
•  To examine the communication between instrument cluster and ABS HU/CM, use the PID on the instrument cluster side.

Module

Communication status

Malfunctioning part

ABS HU/CM

Instrument cluster

PCM
Error
Error
•  Wiring harness A
•  PCM
Error
Normal
•  Wiring harness B
•  ABS HU/CM
Normal
Error
•  Wiring harness C
•  Instrument cluster


Instrument cluster

1.  Using the M-MDS, verify that DTC U1900 is displayed. (See DTC TABLE[MULTIPLEX COMMUNICATION SYSTEM (L3)].)

2.  Access and monitor the “PCM_MSG” and “ABS_MSG” PIDs using the M-MDS.

3.  Verify the PID. (See PID/DATA MONITOR AND RECORD PROCEDURE[L3].)

4.  Referring to the following table, determine the malfunctioning part of the CAN system.

Module

Communication status

Malfunctioning part

PCM

ABS HU/CM

Instrument cluster
Error
Error
•  Wiring harness C
•  Instrument cluster
Error
Normal
•  Wiring harness A
•  PCM
Normal
Error
•  Wiring harness B
•  ABS HU/CM


ABS HU/CM

Note
•  The ABS HU/CM does not have any PID for examining communication between the ABS HU/CM and instrument cluster. Therefore, use the PIDs on the instrument cluster side to determine the location of malfunction.

1.  Using the M-MDS, verify that DTC U1900 or U2023 is displayed. (See DTC TABLE[MULTIPLEX COMMUNICATION SYSTEM (L3)].)

2.  Referring to the following table, determine the malfunctioning part of the CAN system.

Module

Communication status

Malfunction location

PCM

Instrument cluster

ABS HU/CM
Error
Error
•  Wiring harness B
•  ABS HU/CM
Error
Normal
•  Wiring harness A
•  PCM
Normal
Error
•  Wiring harness C
•  Instrument cluster