Diagnosis Item
4: Diagnose shorts between CAN_H and L lines (CAN-C)
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.)
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TROUBLE JUDGEMENT
When all of the following conditions are met,
the M.U.T.-III determines that a short circuit
is present between CAN_L and CAN_H lines.
- The M.U.T.-III cannot receive the periodic transmission
data from any ECUs.
- The voltage between CAN-C (CAN_L and CAN_H lines) is 1.0 V or
more, 4.0 V or less.
- The resistance at CAN-C (CAN_L and CAN_H lines) is 2 Ω
or
less.
TROUBLESHOOTING HINTS
- Malfunction of the wiring harness
- Malfunction of the connector
- Malfunction of the ETACS-ECU
- Malfunction of the SRS-ECU
- Malfunction of the steering wheel sensor
- Malfunction of the 4WD-ECU <4WD (vehicles without S-AWC)> or
AWC-ECU <vehicles
with S-AWC)>
- Malfunction of the ABS-ECU <vehicles without ASC> or ASC-ECU
<vehicles
with ASC>
- Malfunction of the EPS-ECU
- Malfunction of the CVT-ECU <CVT> or A/T-ECU
<A/T>
- Malfunction of the ACC/FCM-ECU <vehicles with ACC>
- Malfunction of the engine-ECU
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STEP 1. Connector check: C-126 intermediate connector
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caution |
The strand end of the twist wire should be within
10 cm from
the connector.
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Q.
Is the check result normal?
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Go to Step 2.
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Repair
the defective connector.
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STEP 2. Resistance measurement at C-126 intermediate
connector.
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caution |
A digital multimeter should be used.
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caution |
The test wiring harness should be used.
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(1)Disconnect the connector, and measure at its female-side
intermediate connector
(at the front wiring harness side).
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(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between C-126 intermediate connector terminal
Nos.15 and 16 OK: 120 ± 20 Ω
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Q.
Is the check result normal?
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<Within 120 ± 20
Ω> Go to Step 15.
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<Not within 120 ± 20
Ω> Go to Step 3.
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STEP 3. Connector check: joint connector (CAN1)
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caution |
The strand end of the twist wire should be within
10 cm from
the connector.
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When checking the joint connector, ensure that
its wiring harness side and its short pins
are not damaged.
Q.
Is the check result normal?
YES <vehicles without
ACC> : Go
to Step 5.
YES <vehicles with ACC> : Go to Step 4.
Repair a defective connector or
replace the joint connector.
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STEP 4. Connector check: joint connector (CAN2)
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caution |
The strand end of the twist wire should be within
10 cm from
the connector.
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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 5.
Repair a defective connector or
replace the joint connector.
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STEP 5. Resistance measurement at joint connector (CAN1).
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caution |
A digital multimeter should be used.
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caution |
The test wiring harness should be used.
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(1)Disconnect the connector, and measure at the wiring
harness side.
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(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN1) terminal Nos.10
and 21 OK: 120 ± 20 Ω
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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YES <vehicles without ACC> : <Within
120 ± 20 Ω> Go to Step 8.
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YES <vehicles with ACC> : <Within
120 ± 20 Ω> Go to Step 7.
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<Not within 120 ± 20
Ω> Go to Step 6.
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STEP 6. Resistance measurement at engine-ECU connector.
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caution |
A digital multimeter should be used.
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(1)Remove the engine-ECU, and measure at the equipment
side.
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(2)Resistance between engine-ECU connector terminal Nos.90
and 91 OK: 120 ± 20 Ω
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<Within 120 ± 20
Ω> Repair the wiring harness between
joint connector (CAN1) and the engine-ECU connector.
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<Not within 120 ± 20
Ω> Check the engine-ECU connector,
and repair if necessary. If the engine-ECU connector is in good condition,
replace the engine-ECU.
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STEP 7. Resistance measurement at joint connector (CAN1).
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caution |
A digital multimeter should be used.
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caution |
The test wiring harness should be used.
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(1)Disconnect the connector, and measure at the wiring
harness side.
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(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN1) terminal Nos.10
and 21 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more>
Go to Step 9.
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<Less than 1
kΩ> Go to Step 8.
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STEP 8. Resistance measurement at ACC/FCM-ECU connector.
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caution |
A digital multimeter should be used.
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(1)Remove the ACC/FCM-ECU, and measure at the equipment
side.
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(2)Resistance between ACC/FCM-ECU connector terminal Nos.2
and 7 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more> Check
intermediate connector, and repair
if necessary. If the intermediate connector is in good condition, repair
the wiring harness
between joint connector (CAN1) and the ACC/FCM-ECU connector.
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<Less than 1 kΩ>
Check the ACC/FCM-ECU connector, and
repair if necessary. If the ACC/FCM-ECU connector is in good condition,
replace the ACC/FCM-ECU.
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STEP 9. Resistance measurement at joint connector (CAN1).
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caution |
A digital multimeter should be used.
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caution |
The test wiring harness should be used.
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(1)Disconnect the connector, and measure at the wiring
harness side.
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(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN1) terminal Nos.6
and 17 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more>
Go to Step 11.
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<Less than 1
kΩ> Go to Step 10.
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STEP 10. Resistance measurement at CVT-ECU <CVT> connector
or A/T-ECU <A/T> connector.
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caution |
A digital multimeter should be used.
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(1)Remove the CVT-ECU <CVT> or A/T-ECU
<A/T>,
and measure at the equipment side.
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(2)Resistance between CVT-ECU connector terminal Nos.4 and 5
<CVT> OK: 1 kΩ or more
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(3)Resistance between A/T-ECU connector terminal Nos.10 and
11 <A/T> OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more> Check
intermediate connector, and repair
if necessary. If the intermediate connector is in good condition, repair
the wiring harness
between joint connector (CAN1) and the CVT-ECU <CVT> connector
or A/T-ECU <A/T> connector.
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<Less than 1 kΩ>
Check the CVT-ECU <CVT> connector
or A/T-ECU <A/T> connector, and repair if necessary. If the
CVT-ECU <CVT> connector
or A/T-ECU <A/T> connector is in good condition, replace the
CVT-ECU <CVT> or
A/T-ECU <A/T>.
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STEP 11. Resistance measurement at joint connector
(CAN1).
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caution |
A digital multimeter should be used.
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caution |
The test wiring harness should be used.
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(1)Disconnect the connector, and measure at the wiring
harness side.
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(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN1) terminal Nos.8
and 19 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more>
Go to Step 13.
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<Less than 1
kΩ> Go to Step 12.
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STEP 12. Resistance measurement at EPS-ECU connector.
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caution |
A digital multimeter should be used.
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(1)Remove the EPS-ECU, and measure at the equipment
side.
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(2)Resistance between EPS-ECU connector terminal Nos.3 and
4 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more>
Repair the wiring harness between joint
connector (CAN1) and the EPS-ECU connector.
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<Less than 1 kΩ>
Check the EPS-ECU connector, and repair
if necessary. If the EPS-ECU connector is in good condition, replace the
EPS-ECU.
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STEP 13. Resistance measurement at joint connector
(CAN1).
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caution |
A digital multimeter should be used.
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caution |
The test wiring harness should be used.
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(1)Disconnect the connector, and measure at the wiring
harness side.
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(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
|
Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN1) terminal Nos.9
and 20 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more>
Repair the wiring harness between joint
connector (CAN1) and C-126 intermediate connector.
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<Less than 1
kΩ> Go to Step 14.
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STEP 14. Resistance measurement at ABS-ECU <vehicles without
ASC> or ASC-ECU <vehicles with ASC>
connector.
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caution |
A digital multimeter should be used.
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(1)Remove the ABS-ECU <vehicles without ASC> or
ASC-ECU <vehicles
with ASC>, and measure at the equipment side.
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(2)Resistance between ABS-ECU <vehicles without
ASC> or ASC-ECU <vehicles
with ASC> connector terminal Nos.11 and 10 OK: 1 kΩ
or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more>
Repair the wiring harness between joint
connector (CAN1) and the ABS-ECU <vehicles without ASC> or
ASC-ECU <vehicles
with ASC> connector.
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<Less than 1 kΩ>
Check the ABS-ECU <vehicles without
ASC> or ASC-ECU <vehicles with ASC> connector, and repair
if necessary.
If the ABS-ECU <vehicles without ASC> or ASC-ECU
<vehicles with ASC> connector
is in good condition, replace the ABS-ECU <vehicles without
ASC> or ASC-ECU <vehicles
with ASC>.
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STEP 15. Connector check: joint connector (CAN3) <LHD> or
joint connector (CAN4) <RHD>
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caution |
The strand end of the twist wire should be within
10 cm from
the connector.
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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 16.
Repair a defective connector or
replace the joint connector.
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STEP 16. Resistance measurement at joint connector
(CAN3).
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caution |
A digital multimeter should be used.
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caution |
The test wiring harness should be used.
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(1)Disconnect joint connector (CAN3), and measure at the
wiring harness side.
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(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
|
Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN3) terminal Nos.11
and 22 <LHD> OK: 120 ± 20
Ω
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(5)Resistance between joint connector (CAN3) terminal Nos.4
and 15 <RHD> OK: 120 ± 20
Ω
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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YES <2WD> : <Within 120 ± 20
Ω> Go to Step 20.
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YES <4WD> : <Within 120 ± 20
Ω> Go to Step 18.
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NO : <Not within 120 ±
20 Ω> Go to Step 17.
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STEP 17. Resistance measurement at ETACS-ECU connector.
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caution |
A digital multimeter should be used.
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(1)Remove the ETACS-ECU, and measure at the equipment
side.
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(2)Resistance at ETACS-ECU connector terminal Nos.18 and
19 OK: 120 ± 20 Ω
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Q.
Is the check result normal?
|
|
<Within 120 ± 20
Ω> Repair the wiring harness between
joint connector (CAN3) and the ETACS-ECU connector.
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<Not within 120 ± 20
Ω> Check the ETACS-ECU connector,
and repair if necessary. If the ETACS-ECU connector is in good condition,
replace the ETACS-ECU.
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STEP 18. Resistance measurement at joint connector
(CAN3).
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|
caution |
A digital multimeter should be used.
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caution |
The test wiring harness should be used.
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|
(1)Disconnect joint connector (CAN3), and measure at the
wiring harness side.
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(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
|
Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN3) terminal Nos.5
and 16 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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<1 kΩ or more>
Go to Step 20.
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<Less than 1
kΩ> Go to Step 19.
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STEP 19. Resistance measurement at 4WD-ECU connector <4WD
(vehicles without S-AWC)> or AWC-ECU connector <vehicles with
S-AWC)>.
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caution |
A digital multimeter should be used.
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(1)Remove the 4WD-ECU <4WD (vehicles without
S-AWC)> or AWC-ECU <vehicles
with S-AWC)>, and measure at the equipment side.
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(2)Resistance at 4WD-ECU connector terminal Nos.5 and 13
<4WD (vehicles without
S-AWC)> or AWC-ECU connector terminal Nos.23 and 24 <vehicles
with S-AWC)> OK: 1 kΩ or more
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Q.
Is the check result normal?
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<1 kΩ or more> Check
intermediate connector, and repair
if necessary. If the intermediate connector is in good condition, repair
the wiring harness
between joint connector (CAN3) and the 4WD-ECU connector <4WD
(vehicles without S-AWC)> or
AWC-ECU connector <vehicles with S-AWC)>.
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<Less than 1 kΩ>
Check the 4WD-ECU connector <4WD
(vehicles without S-AWC)> or AWC-ECU connector <vehicles with
S-AWC)>,
and repair if necessary. If the 4WD-ECU connector <4WD (vehicles
without S-AWC)> or
AWC-ECU connector <vehicles with S-AWC)> is in good condition,
replace the
4WD-ECU <4WD (vehicles without S-AWC)> or AWC-ECU
<vehicles with
S-AWC)>.
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STEP 20. Resistance measurement at joint connector
(CAN3).
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|
caution |
A digital multimeter should be used.
|
|
|
caution |
The test wiring harness should be used.
|
|
|
(1)Disconnect joint connector (CAN3), and measure at the
wiring harness side.
|
|
(2)Turn the ignition switch to the LOCK (OFF)
position.
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(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
|
Ensure that the negative battery terminal is disconnected.
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|
(4)Resistance between joint connector (CAN3) terminal Nos.6
and 17 <LHD> OK: 1 kΩ or more
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(5)Resistance between joint connector (CAN3) terminal Nos.4
and 15 <RHD> OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
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Q.
Is the check result normal?
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|
<1 kΩ or more>
Go to Step 22.
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<Less than 1
kΩ> Go to Step 21.
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STEP 21. Resistance measurement at steering wheel sensor
connector.
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caution |
A digital multimeter should be used.
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|
(1)Remove the steering wheel sensor, and measure at the
equipment side.
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(2)Resistance at steering wheel sensor connector terminal
Nos.3 and 4 OK: 1 kΩ or more
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Q.
Is the check result normal?
|
|
<1 kΩ or more>
Repair the wiring harness between joint
connector (CAN3) and the steering wheel sensor connector.
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<Less than 1 kΩ>
Check the steering wheel sensor connector,
and repair if necessary. If the steering wheel sensor connector is in good
condition, replace the
steering wheel sensor.
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STEP 22. Resistance measurement at joint connector
(CAN3).
|
|
caution |
A digital multimeter should be used.
|
|
|
caution |
The test wiring harness should be used.
|
|
|
(1)Disconnect joint connector (CAN3), and measure at the
wiring harness side.
|
|
(2)Turn the ignition switch to the LOCK (OFF)
position.
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|
(3)
caution |
When measuring the resistance, disconnect the
negative battery
terminal.
|
Ensure that the negative battery terminal is disconnected.
|
|
(4)Resistance between joint connector (CAN3) terminal Nos.8
and 19 <LHD> OK: 1 kΩ or more
|
|
(5)Resistance between joint connector (CAN3) terminal Nos.4
and 15 <RHD> OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
|
|
|
Q.
Is the check result normal?
|
|
<1 kΩ or more>
Go to Step 24.
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<Less than 1
kΩ> Go to Step 23.
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STEP 23. Resistance measurement at SRS-ECU connector.
|
|
caution |
A digital multimeter should be used.
|
|
|
(1)Remove the SRS-ECU, and measure at the equipment
side.
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|
(2)Resistance at SRS-ECU connector terminal Nos.29 and
30 OK: 1 kΩ or more
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|
Q.
Is the check result normal?
|
|
<1 kΩ or more>
Repair the wiring harness between joint
connector (CAN3) and the SRS-ECU connector.
|
|
|
|
<Less than 1 kΩ>
Check the SRS-ECU connector, and repair
if necessary. If the SRS-ECU connector is in good condition, replace the
SRS-ECU.
|
|
|
|
STEP 24. Resistance measurement at joint connector
(CAN3).
|
|
caution |
A digital multimeter should be used.
|
|
|
caution |
The test wiring harness should be used.
|
|
|
(1)Disconnect the joint connector (CAN3), 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)Resistance between joint connector (CAN3) terminal Nos.9
and 20 <LHD> OK: 1 kΩ or more
|
|
(5)Resistance between joint connector (CAN3) terminal Nos.4
and 15 <RHD> OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
|
|
|
Q.
Is the check result normal?
|
|
<1 kΩ or more>
Repair the wiring harness between joint
connector (CAN3) and the C-126 intermediate connector.
|
|
|
|
<Less than 1 kΩ>
Check the diagnosis connector, and
repair if necessary. If the diagnosis connector is in good condition,
repair the wiring harness
between joint connector (CAN3) and the diagnosis connector.
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|
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