M-MDS AND VEHICLE NOT COMMUNICATING [MULTIPLEX COMMUNICATION SYSTEM (R.H.D.)]

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Caution

•  Perform the following on-board diagnosis according to FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (R.H.D.)] troubleshooting procedure.

Detection Condition

Possible Causes

Wiring Diagram

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Diagnostic Procedure

Caution

•  When disconnecting the connector, verify that there is no looseness, damage, deformation, corrosion, or poor connection of the connector terminals.

Step	Inspection		Action
1	VERIFICATION BEFORE SERVICING •  Is there communication between the M-MDS and vehicle?	Yes	Go to the next step.
		No	Go back to FOREWORD [MULTIPLEX COMMUNICATION SYSTEM. (See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (R.H.D.)].)
2	VERIFY THAT M-MDS AND DLC-2 ARE CONNECTED •  Verify the connection condition between the M-MDS and DLC-2. •  Are the connector terminals normal without damage, deformation, corrosion, or disconnection?	Yes	Go to the next step.
		No	Correct the connection condition, then go to Step 13.
3	VERIFY PCM POWER SUPPLY CONDITION •  Refer to the PCM terminal voltage table and inspect the terminal voltage and fuse condition. (See PCM INSPECTION [MZI-3.7].) •  Is the power supply condition normal?	Yes	Go to the next step.
		No	Repair or replace the fuse or wiring harness, then go to Step 13.
4	VERIFY PCM BODY GROUND CONDITION •  Inspect the PCM body ground wiring harness and ground point. •  Are the ground and ground point normal?	Yes	Go to the next step.
		No	Repair or replace the wiring harness, then go to Step 13.
5	INSPECT PCM CONNECTOR TERMINAL •  Disconnect the negative battery cable. •  Disconnect the PCM connector. •  Are the PCM connector terminal normal without damage, deformation, corrosion, or disconnection?	Yes	Go to the next step.
		No	Repair the connector terminal if necessary, then go to Step 13.
6	INSPECT PCM •  Disconnect the PCM connector. •  Measure the resistance between the following PCM connector terminals: ―  Between terminal 1AH and terminal 1AL (part side) •  Is the resistance 118—130 ohms?	Yes	Go to the next step.
		No	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [MZI-3.7].)
7	VERIFY THAT THERE IS NO OPEN CIRCUIT IN CAN COMMUNICATION WIRING HARNESS Caution •  When inspecting the DLC-2, touch it with a paper clip or similar thin pin without directly inserting a tester into the terminals. •  Verify the continuity between the following terminals: ―  Between DLC-2 terminal F and PCM terminal 1AH ―  Between DLC-2 terminal E and PCM terminal 1AL •  Is there continuity?	Yes	Go to the next step.
		No	There is an open circuit in the CAN communication wiring harness. Repair or replace it, then go to Step 13.
8	INSPECT CAN COMMUNICATION WIRING HARNESS IN BCM FOR OPEN CIRCUIT •  Verify the continuity between the following terminals: ―  Between BCM terminal 1L and BCM terminal 6I ―  Between BCM terminal 1J and BCM terminal 6G •  Is there continuity?	Yes	Go to the next step.
		No	Replace the BCM which has an open circuit in the CAN communication wiring harness in the BCM, then go to Step 13. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)
9	VERIFY THAT THERE IS NO SHORT CIRCUIT IN CAN COMMUNICATION WIRING HARNESS Caution •  When inspecting the DLC-2, touch it with a paper clip or similar thin pin without directly inserting a tester into the terminals. •  Measure the resistance between the terminals. ―  Between DLC-2 terminal F and DLC-2 terminal E •  Is the resistance 60 ohms or less?	Yes	There is an open circuit in the CAN communication wiring harness. Repair or replace it, then go to Step 13.
		No	Go to the next step.
10	VERIFY NO SHORT CIRCUIT TO GROUND IN CAN COMMUNICATION WIRING HARNESS Caution •  When inspecting the DLC-2, touch it with a paper clip or similar thin pin without directly inserting a tester into the terminals. •  Verify the continuity between the following terminals: ―  Between DLC-2 terminal F and ground ―  Between DLC-2 terminal E and ground ―  Between PCM terminal 1AH and ground ―  Between PCM terminal 1AL and ground •  Is there continuity?	Yes	There is a short circuit to ground in the CAN communication wiring harness. Repair or replace it, then go to Step 13.
		No	Go to the next step.
11	VERIFY NO SHORT CIRCUIT TO POWER SUPPLY SYSTEM IN CAN COMMUNICATION WIRING HARNESS Caution •  When inspecting the DLC-2, touch it with a paper clip or similar thin pin without directly inserting a tester into the terminals. •  Verify the continuity between the following terminals: ―  Between DLC-2 terminal F and DLC-2 terminal A ―  Between DLC-2 terminal E and DLC-2 terminal A ―  Between PCM terminal 1AH and PCM terminal 1V ―  Between PCM terminal 1AL and PCM terminal 1V •  Is there continuity?	Yes	There is a short circuit to the power supply system in the CAN communication wiring harness. Repair or replace it, then go to Step 13.
		No	Go to the next step.
12	INSPECT CAN-RELATED MODULES OTHER THAN PCM and BCM •  Remove only one of the CAN-related modules other than those related to the PCM and BCM. •  Connect the negative battery cable. •  Connect the M-MDS to the DLC-2. •  Does the M-MDS recognize the vehicle?	Yes	Replace the removed module.
		No	Inspect all of the CAN-related modules other than those related to the PCM and BCM using the same procedure. After inspecting all of the modules, go to the next step.
13	PERFORM VEHICLE IDENTIFICATION •  Connect the M-MDS to the DLC-2. •  Does the M-MDS recognize the vehicle?	Yes	DTC troubleshooting completed.
		No	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [MZI-3.7].)
14	PERFORM VEHICLE IDENTIFICATION •  Connect the M-MDS to the DLC-2. •  Does the M-MDS recognize the vehicle?	Yes	DTC troubleshooting completed.
		No	Replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)