Diagnosis Item
18: Diagnose when the M.U.T.-III cannot receive the data sent by electric parking brake ECU <Vehicles
with electric parking brake system>.
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 electric parking brake-ECU" when the M.U.T.-III checks the periodically sent data from each
ECU and cannot receive the electric parking brake ECU data only.
TROUBLE JUDGEMENT CONDITIONS
M.U.T.-III judges the trouble when the periodically sent data from electric parking brake
ECU cannot be received.
PROBABLE CAUSES
- Damaged harness wires and connectors
- Power supply circuit malfunction of the electric parking brake ECU
- Malfunction of the electric parking brake ECU
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STEP 1. Connector check: joint connector (CAN1) and electric
parking brake ECU 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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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 (CAN1) and electric
parking brake ECU 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 joint connector (CAN1) and the electric parking brake-ECU 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 (CAN1) terminal No.2 and electric parking brake
ECU connector terminal No.26 OK: Continuity (2 Ω or less)
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(5)Continuity between joint connector (CAN1) terminal No.13 and electric parking brake
ECU connector terminal No.18 OK: Continuity (2 Ω or less)
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Q.
Is the check result normal?
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<All the resistances measure 2 Ω or less> Power supply
to the electric parking brake ECU may be suspected. Diagnose the electric parking brake system
(Refer to GROUP 36 - Troubleshooting ).
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NO : <Either or all of the resistances measure more than 2 Ω> Check
the intermediate connector, and repair if necessary. If the intermediate connector is in good condition,
repair the wiring harness between joint connector (CAN1) and the electric parking brake ECU connector.
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