Diagnosis Item
16: Diagnose when the M.U.T.-III cannot receive the data sent by ABS-ECU <vehicles without
ASC> or ASC-ECU <vehicles with ASC>.
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 ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC>" when the M.U.T.-III
checks the periodically sent data from each ECU and cannot receive the ABS-ECU <vehicles
without ASC> or ASC-ECU <vehicles with ASC> data only.
TROUBLE JUDGEMENT CONDITIONS
M.U.T.-III judges the trouble when the periodically sent data from ABS-ECU <vehicles
without ASC> or ASC-ECU <vehicles with ASC> cannot be received.
PROBABLE CAUSES
Damaged harness wires and connectors
Power supply circuit malfunction of the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with
ASC>
Malfunction of the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with
ASC>
DIAGNOSIS PROCEDURE
STEP 1. Connector check: joint connector (CAN1) and ABS-ECU <vehicles
without ASC> or ASC-ECU <vehicles with ASC> 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 (CAN1) and ABS-ECU <vehicles
without ASC> or ASC-ECU <vehicles with ASC> 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 (CAN1) and the ABS-ECU <vehicles without ASC> or
ASC-ECU <vehicles with ASC> 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 (CAN1) terminal No.9 and ABS-ECU <vehicles
without ASC> or ASC-ECU <vehicles with ASC> connector terminal No.11 OK: Continuity (2 Ω or less)
(5)Continuity between joint connector (CAN1) terminal No.20 and ABS-ECU <vehicles
without ASC> or ASC-ECU <vehicles with ASC> connector terminal No.10 OK: Continuity (2 Ω or less)
Q.
Is the check result normal?
<All the resistances measure 2 Ω or less> Power supply
to the ABS-ECU <vehicles without ASC> or ASC-ECU <vehicles with ASC> may be suspected. Diagnose
the ABS <vehicles without ASC> Refer to GROUP 35B - Troubleshooting ,
or ASC <vehicles with ASC> Refer to GROUP 35C - Troubleshooting .
NO : <Either or all of the resistances measure more than 2 Ω> Repair
the wiring harness between joint connector (CAN1) and the ABS-ECU <vehicles without ASC>
or ASC-ECU <vehicles with ASC> connector.