Diagnosis Item
6: Diagnose when the M.U.T.-III cannot receive the data sent by steering wheel sensor <Vehicles
with ASTC>.
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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FUNCTION
The diagnostic result demonstrates that "the M.U.T.-III cannot receive the sent data from
the steering wheel sensor" when the M.U.T.-III checks the periodically sent data from each ECU
and cannot receive the steering wheel sensor data only.
TROUBLE JUDGEMENT CONDITIONS
M.U.T.-III judges the trouble when the periodically sent data from steering wheel sensor
cannot be received.
PROBABLE CAUSES
- Damaged harness wires and connectors
- Power supply circuit malfunction of the steering wheel sensor
- Malfunction of the steering wheel sensor
DIAGNOSIS PROCEDURE
STEP 1. Connector check: joint connector (CAN2) and steering
wheel sensor connector
caution |
The strand end of the twist wire should be within 10 cm from
the connector. For details refer to .
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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 2.
Repair the defective connector. Replace the joint connector as necessary.
STEP 2. Resistance measurement at joint connector (CAN2) and steering
wheel sensor connector.
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 (CAN2) and the steering wheel sensor 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)Continuity between joint connector (CAN2) terminal No.7 and steering wheel sensor connector
terminal No.3 OK: Continuity (2 Ω or less)
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(5)Continuity between joint connector (CAN2) terminal No.18 and steering wheel sensor connector
terminal No.4 OK: Continuity (2 Ω or less)
caution |
Strictly observe the specified wiring harness repair procedure.
For details refer to .
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Q.
Is the check result normal?
<All the resistances measure 2 Ω or less> Power supply
to the steering wheel sensor may be suspected. Diagnose the steering wheel sensor (Refer to
GROUP 35C - Troubleshooting <Steering wheel sensor>,
).
NO : <Either or all of the resistances measure more than 2 Ω> Repair
the wiring harness between joint connector (CAN2) and the steering wheel sensor.