Diagnosis Item
28: Diagnose when the M.U.T.-III cannot receive the data sent by combination meter.
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 combination meter" when the M.U.T.-III checks the periodically sent data from each ECU and
cannot receive the combination meter data only.
TROUBLE JUDGEMENT CONDITIONS
M.U.T.-III judges the trouble when the periodically sent data from combination meter cannot
be received.
PROBABLE CAUSES
- Damaged harness wires and connectors
- Power supply circuit malfunction of the combination meter
- Malfunction of the combination meter
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STEP 1. Connector check: joint connector (CAN5) and combination
meter 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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When checking the joint connector, ensure that its wiring harness side and its short pins
are not damaged.
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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. Replace the joint connector as necessary.
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STEP 2. Resistance measurement at joint connector (CAN5) and combination
meter 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 joint connector (CAN5) and the combination meter 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)Continuity between joint connector (CAN5) terminal No.9 and combination meter connector
terminal No.14 OK: Continuity (2 Ω or less)
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(5)Continuity between joint connector (CAN5) terminal No.20 and combination meter
connector terminal No.15 OK: Continuity (2 Ω or less)
caution |
Strictly observe the specified wiring harness repair procedure.
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Q.
Is the check result normal?
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<All the resistances measure 2 Ω or less> Go to Step 3
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NO : <Either or all of the resistances measure more than 2 Ω> Repair
the wiring harness between joint connector (CAN5) and the combination meter.
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STEP 3. Resistance measurement at combination meter connector.
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caution |
A digital multimeter should be used.
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(1)Remove the combination meter, and measure at the equipment side.
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(2)Resistance between combination meter connector terminal Nos.14 and 15 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> Power supply to the combination meter
may be suspected. Diagnose the combination meter. Refer to GROUP 54A Combination Meter - Troubleshooting.
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<Not within 120 ± 20 Ω> Replace the combination meter.
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