Diagnosis Item
13: Diagnose when the M.U.T.-III cannot receive the data sent by ETACS-ECU.
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.
- When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition
key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine
cannot be started. Register the encrypted code as described in GROUP 54A, Immobilizer System - How
to Register Key ID.)
|
FUNCTION
The diagnostic result demonstrates that "the M.U.T.-III cannot receive the sent data from
the ETACS-ECU" when the M.U.T.-III checks the periodically sent data from each ECU and cannot
receive the ETACS-ECU data only.
TROUBLE JUDGEMENT CONDITIONS
M.U.T.-III judges the trouble when the periodically sent data from ETACS-ECU cannot be
received.
PROBABLE CAUSES
- Damaged harness wires and connectors
- Power supply circuit malfunction of the ETACS-ECU
- Malfunction of the ETACS-ECU
|
STEP 1. Connector check: joint connector (CAN3) <LHD> or
joint connector (CAN4) <RHD> and ETACS-ECU connector
|
|
caution |
The strand end of the twist wire should be within 10 cm from
the connector.
|
|
|
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 (CAN3) <LHD> or
joint connector (CAN4) <RHD> and ETACS-ECU connector.
|
|
caution |
A digital multimeter should be used.
|
|
|
caution |
The test wiring harness should be used.
|
|
|
(1)Disconnect the joint connector (CAN3) <LHD> or joint connector
(CAN4) <RHD> and the ETACS-ECU 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.
|
Ensure that the negative battery terminal is disconnected.
|
|
(4)Continuity between joint connector (CAN3) terminal No.11 and ETACS-ECU connector
terminal No.19 <LHD> OK: Continuity (2 Ω or less)
|
|
(5)Continuity between joint connector (CAN3) terminal No.22 and ETACS-ECU connector
terminal No.18 <LHD> OK: Continuity (2 Ω or less)
|
|
(6)Continuity between joint connector (CAN4) terminal No.5 and ETACS-ECU connector
terminal No.19 <RHD> OK: Continuity (2 Ω or less)
|
|
(7)Continuity between joint connector (CAN4) terminal No.14 and ETACS-ECU connector
terminal No.18 <RHD> OK: Continuity (2 Ω or less)
caution |
Strictly observe the specified wiring harness repair procedure.
|
|
|
Q.
Is the check result normal?
|
|
<All the resistances measure 2 Ω or less> Go to Step 3
.
|
|
|
|
NO : <Either or all of the resistances measure more than 2 Ω> Repair
the wiring harness between joint connector (CAN3) <LHD> or joint connector
(CAN4) <RHD> and the ETACS-ECU connector.
|
|
|
|
STEP 3. Resistance measurement at ETACS-ECU connector.
|
|
caution |
A digital multimeter should be used.
|
|
|
(1)Remove the ETACS-ECU, and measure at the equipment side.
|
|
(2)Resistance at ETACS-ECU connector terminal Nos.18 and 19 OK: 120 ± 20 Ω
|
|
Q.
Is the check result normal?
|
|
<Within 120 ± 20 Ω> Power supply to the ETACS-ECU
may be suspected. Diagnose the ETACS. Refer to GROUP 54A ETACS - Troubleshooting.
|
|
|
|
<Not within 120 ± 20 Ω> Replace the ETACS-ECU.
|
|
|