Diagnosis Item
4: Diagnose shorts between CAN_H and L lines
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.
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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 bus lines (CAN_L and CAN_H lines) is
1.0
V or more, 4.0 V or less.
- The resistance at CAN bus line (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 combination meter
- Malfunction of the SRS-ECU
- Malfunction of the KOS&OSS-ECU
- Malfunction of the A/C-ECU
- Malfunction of the EPS-ECU
- Malfunction of the ABS-ECU
- Malfunction of the CVT-ECU
- Malfunction of the engine-ECU
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STEP 1. Connector check: C-212 intermediate connector
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caution |
The strand end of the twist wire should be within
10 cm from
the connector. For details refer to .
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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-212 intermediate
connector.
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caution |
A digital multimeter should be used. For details
refer to .
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caution |
The test wiring harness should be used. For details
refer
to .
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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. For details refer to .
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between C-212 intermediate connector terminal
Nos.17 and 8 <LHD> OK: 120 ± 20
Ω
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(5)Resistance between C-212 intermediate connector terminal
Nos.6 and 7 <RHD> 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 12.
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<Not within 120 ± 20
Ω> Go to Step 3.
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STEP 3. 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. For details refer to .
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![](../../../img/54/AC209350AC00ENG.png)
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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 4.
Repair a defective connector or
replace the joint connector.
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STEP 4. Resistance measurement at joint connector (CAN2).
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caution |
A digital multimeter should be used. For details
refer to .
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caution |
The test wiring harness should be used. For details
refer
to .
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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. For details refer to .
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN2) terminal Nos.11
and 22 OK: 120 ± 20 Ω
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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Q.
Is the check result normal?
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YES <CVT> : <Within 120 ± 20
Ω> Go to Step 6.
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YES <M/T (with ABS)> : <Within
120 ± 20 Ω> Go to Step 8.
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YES <M/T (without ABS)> : <Within
120 ± 20 Ω> Go to Step 10.
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NO : <Not within 120 ±
20 Ω> Go to Step 5.
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STEP 5. Resistance measurement at engine-ECU connector.
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caution |
A digital multimeter should be used. For details
refer to .
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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.71
and 72 OK: 120 ± 20 Ω
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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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 (CAN2) 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 6. Resistance measurement at joint connector (CAN2).
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caution |
A digital multimeter should be used. For details
refer to .
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caution |
The test wiring harness should be used. For details
refer
to .
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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. For details refer to .
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN2) terminal Nos.7
and 18 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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Q.
Is the check result normal?
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<1 kΩ or more>
Go to Step 8.
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<Less than 1
kΩ> Go to Step 7.
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STEP 7. Resistance measurement at CVT-ECU connector.
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caution |
A digital multimeter should be used. For details
refer to .
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(1)Remove the CVT-ECU, and measure at the equipment
side.
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(2)Resistance between CVT-ECU connector terminal Nos.9 and
10 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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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 (CAN2) and the CVT-ECU connector.
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<Less than 1 kΩ>
Check the CVT-ECU connector, and repair
if necessary. If the CVT-ECU connector is in good condition, replace the
CVT-ECU.
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STEP 8. Resistance measurement at joint connector (CAN2).
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caution |
A digital multimeter should be used. For details
refer to .
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caution |
The test wiring harness should be used. For details
refer
to .
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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. For details refer to .
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN2) terminal Nos.10
and 21 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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Q.
Is the check result normal?
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<1 kΩ or more>
Go to Step 10.
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<Less than 1
kΩ> Go to Step 9.
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STEP 9. Resistance measurement at ABS-ECU connector.
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caution |
A digital multimeter should be used. For details
refer to .
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(1)Remove the ABS-ECU, and measure at the equipment
side.
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(2)Resistance between ABS-ECU connector terminal Nos.34 and
23 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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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 (CAN2) and the ABS-ECU connector.
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<Less than 1 kΩ>
Check the ABS-ECU connector, and repair
if necessary. If the ABS-ECU connector is in good condition, replace the
ABS-ECU.
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STEP 10. Resistance measurement at joint connector
(CAN2).
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caution |
A digital multimeter should be used. For details
refer to .
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caution |
The test wiring harness should be used. For details
refer
to .
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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. For details refer to .
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN2) terminal Nos.8
and 19 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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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 (CAN2) and C-212 intermediate connector.
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<Less than 1
kΩ> Go to Step 11.
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STEP 11. Resistance measurement at EPS-ECU connector.
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caution |
A digital multimeter should be used. For details
refer to .
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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.
For details refer to .
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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 (CAN2) 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 12. 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. For details refer to .
|
|
![](../../../img/54/AC209350AC00ENG.png)
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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 13.
Repair a defective connector or
replace the joint connector.
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STEP 13. Resistance measurement at joint connector
(CAN1).
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caution |
A digital multimeter should be used. For details
refer to .
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caution |
The test wiring harness should be used. For details
refer
to .
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|
(1)Disconnect joint connector (CAN1), 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. For details refer to .
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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.
For details refer to .
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Q.
Is the check result normal?
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YES <vehicles with KOS> : <Within
120 ± 20 Ω> Go to Step 15.
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YES <vehicles without KOS> : <Within
120 ± 20 Ω> Go to Step 17.
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NO : <Not within 120 ±
20 Ω> Go to Step 14.
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STEP 14. Resistance measurement at ETACS-ECU connector.
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caution |
A digital multimeter should be used. For details
refer to .
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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.56 and
65 OK: 120 ± 20 Ω
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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 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 15. Resistance measurement at joint connector
(CAN1).
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caution |
A digital multimeter should be used. For details
refer to .
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caution |
The test wiring harness should be used. For details
refer
to .
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|
(1)Disconnect joint connector (CAN1), 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. For details refer to .
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN1) terminal Nos.11
and 22 <LHD> OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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(5)Resistance between joint connector (CAN1) terminal Nos.2
and 13 <RHD> OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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Q.
Is the check result normal?
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<1 kΩ or more>
Go to Step 17.
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<Less than 1
kΩ> Go to Step 16.
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STEP 16. Resistance measurement at KOS&OSS-ECU
connector.
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caution |
A digital multimeter should be used. For details
refer to .
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(1)Remove the KOS&OSS-ECU, and measure at the equipment
side.
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(2)Resistance at KOS&OSS-ECU connector terminal Nos.35
and 51 OK: 1 kΩ or more
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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 KOS&OSS-ECU connector.
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<Less than 1 kΩ>
Check the KOS&OSS-ECU connector,
and repair if necessary. If the KOS&OSS-ECU connector is in good
condition, replace
the KOS&OSS-ECU.
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STEP 17. Resistance measurement at joint connector
(CAN1).
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caution |
A digital multimeter should be used. For details
refer to .
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|
caution |
The test wiring harness should be used. For details
refer
to .
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|
(1)Disconnect joint connector (CAN1), 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. For details refer to .
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Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN1) terminal Nos.7
and 18 <LHD> OK: 1 kΩ or more
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(5)Resistance between joint connector (CAN1) terminal Nos.1
and 12 <RHD> OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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Q.
Is the check result normal?
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<1 kΩ or more>
Go to Step 19.
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<Less than 1
kΩ> Go to Step 18.
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STEP 18. Resistance measurement at A/C-ECU
connector.
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caution |
A digital multimeter should be used. For details
refer to .
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(1)Remove the A/C-ECU, and measure at the equipment
side.
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(2)Resistance at A/C-ECU connector terminal Nos.12 and
11 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 (CAN1) and the A/C-ECU connector.
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<Less than 1 kΩ>
Check the A/C-ECU connector,
and repair if necessary. If the A/C-ECU connector is in good
condition, replace the
A/C-ECU.
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STEP 19. Resistance measurement at joint connector
(CAN1).
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|
caution |
A digital multimeter should be used. For details
refer to .
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|
caution |
The test wiring harness should be used. For details
refer
to .
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|
(1)Disconnect joint connector (CAN1), 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. For details refer to .
|
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.
For details refer to .
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Q.
Is the check result normal?
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|
<1 kΩ or more>
Go to Step 21.
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<Less than 1
kΩ> Go to Step 20.
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STEP 20. Resistance measurement at combination meter
connector.
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caution |
A digital multimeter should be used. For details
refer to .
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(1)Remove the combination meter, and measure at the equipment
side.
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(2)Resistance at combination meter connector terminal Nos.14
and 15 OK: 1 kΩ or more
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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 combination meter connector.
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<Less than 1 kΩ>
Check the combination meter connector,
and repair if necessary. If the combination meter connector is in good
condition, replace the combination
meter.
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STEP 21. Resistance measurement at joint connector
(CAN1).
|
|
caution |
A digital multimeter should be used. For details
refer to .
|
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|
caution |
The test wiring harness should be used. For details
refer
to .
|
|
|
(1)Disconnect joint connector (CAN1), 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. For details refer to .
|
Ensure that the negative battery terminal is disconnected.
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(4)Resistance between joint connector (CAN1) terminal Nos.4
and 15 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
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|
Q.
Is the check result normal?
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|
<1 kΩ or more>
Go to Step 23.
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<Less than 1
kΩ> Go to Step 22.
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STEP 22. Resistance measurement at SRS-ECU connector.
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caution |
A digital multimeter should be used. For details
refer to .
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(1)Remove the SRS-ECU, and measure at the equipment
side.
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(2)Resistance at SRS-ECU connector terminal Nos.27 and
29 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 (CAN1) and the SRS-ECU connector.
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|
<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.
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|
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STEP 23. Resistance measurement at joint connector
(CAN1).
|
|
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 the joint connector (CAN1), 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)Resistance between joint connector (CAN1) terminal Nos.8
and 19 OK: 1 kΩ or more
caution |
Strictly observe the specified wiring harness repair
procedure.
For details refer to .
|
|
|
Q.
Is the check result normal?
|
|
<1 kΩ or more>
Repair the wiring harness between joint
connector (CAN1) and the C-212 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 (CAN1) and the diagnosis connector.
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