Diagnosis Item 35: Diagnose when the M.U.T.-III cannot receive the data sent by 1CD player. <Vehicles with 1CD audio>



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.

FUNCTION


The diagnostic result demonstrates that "the M.U.T.-III cannot receive the sent data from the 1CD audio" when the M.U.T.-III checks the periodically sent data from each ECU and cannot receive the radio and 1CD audio data only.

TROUBLE JUDGEMENT CONDITIONS


M.U.T.-III judges the trouble when the periodically sent data from 1CD audio cannot be received.

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Connector check: joint connector (CAN5) and radio and CD player connector


caution The strand end of the twist wire should be within 10 cm from the connector.
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 (CAN5) and radio and CD player connector.


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN5) and the radio and CD player connector, 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)Continuity between joint connector (CAN5) terminal No.7 and radio and CD player connector terminal No.3
OK: Continuity (2 Ω or less)
(5)Continuity between joint connector (CAN5) terminal No.18 and radio and CD player connector terminal No.13
OK: Continuity (2 Ω or less)
caution Strictly observe the specified wiring harness repair procedure.

Q. Is the check result normal?

<All the resistances measure 2 Ω or less> Go to Step 3.
NO : <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN5) and the radio and CD player connector.

STEP 3. Resistance measurement at radio and CD player connector.


caution A digital multimeter should be used.
(1)Remove the radio and CD player, and measure at the equipment side.
(2)Resistance between radio and CD player connector terminal Nos.3 and 13
OK: 1 kΩ or more

Q. Is the check result normal?

Power supply to the radio and CD player may be suspected. Diagnose the 1CD audio. Refer to GROUP 54A - Troubleshooting.
Replace the radio and CD player.