Diagnosis Item
25: Diagnose when the M.U.T.-III cannot receive the data sent by CAN box unit <vehicles
with MMCS>.
caution
When servicing a CAN bus line,
earth yourself by touching a metal object such as an unpainted water pipe. If you fail to do,
a component connected to the CAN bus line may be broken.
FUNCTION
The diagnostic result demonstrates that "the M.U.T.-III cannot receive the sent data from
the CAN box unit and multivision display" when the M.U.T.-III checks the periodically sent data
from each ECU and cannot receive the CAN box unit and multivision display data only.
TROUBLE JUDGEMENT CONDITIONS
M.U.T.-III judges the trouble when the periodically sent data from CAN box unit and multivision
display cannot be received.
PROBABLE CAUSES
Damaged harness wires and connectors
Power supply circuit malfunction of the CAN box unit and multivision display
Malfunction of the CAN box unit
Malfunction of the multivision display
DIAGNOSIS PROCEDURE
STEP 1. Connector check: joint connector (CAN5) and CAN
box unit and multivision display connector
caution
The strand end of the twist wire should be within 10 cm from
the connector. For details refer to .
When checking the joint connector, ensure that its wiring harness side and its short pins
are not damaged.
Q.
Is the check result normal?
Go to Step 2.
Repair the defective connector. Replace the joint connector as necessary.
STEP 2. Resistance measurement at joint connector (CAN5) and CAN box
unit connector and multivision display connector.
caution
A digital multimeter should be used. For details refer to .
caution
The test wiring harness should be used. For details refer
to .
(1)Disconnect joint connector (CAN5) and the CAN box unit connector and multivision
display connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the LOCK (OFF) position.
(3)
caution
When measuring the resistance, disconnect the negative battery
terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(4)Continuity between joint connector (CAN5) terminal No.3 and CAN box unit connector
terminal No.14 OK: Continuity (2 Ω
or less)
(5)Continuity between joint connector (CAN5) terminal No.14 and CAN box unit connector
terminal No.13 OK: Continuity (2 Ω
or less)
(6)Continuity between joint connector (CAN5) terminal No.7 and multivision display
connector terminal No.13 OK: Continuity (2 Ω
or less)
(7)Continuity between joint connector (CAN5) terminal No.18 and multivision display
connector terminal No.23 OK: Continuity (2 Ω
or less)
caution
Strictly observe the specified wiring harness repair procedure.
For details refer to .
Q.
Is the check result normal?
<All the resistances measure 2 Ω
or less>
Power supply
to the CAN box unit and multivision display may be suspected. Diagnose the MMCS.
NO : <Either or all of the resistances measure more than 2 Ω>
Repair
the wiring harness between joint connector (CAN5) and the CAN box unit connector and multivision
display connector.