Diagnosis Item 38: Diagnose when the M.U.T.-III cannot receive the data sent by camera-ECU. <Vehicles with multi around monitor>



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 camera-ECU" when the M.U.T.-III checks the periodically sent data from each ECU and cannot receive the camera-ECU data only.

TROUBLE JUDGEMENT CONDITIONS


M.U.T.-III judges the trouble when the periodically sent data from camera-ECU cannot be received.

PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Connector check: joint connector (CAN5) and camera-ECU 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 camera-ECU connector.


caution A digital multimeter should be used.
caution The test wiring harness should be used.
(1)Disconnect joint connector (CAN5) and the camera-ECU 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.4 and camera-ECU connector terminal No.1 <LHD>
OK: Continuity (2 Ω or less)
(5)Continuity between joint connector (CAN5) terminal No.15 and camera-ECU connector terminal No.21 <LHD>
OK: Continuity (2 Ω or less)
(6)Continuity between joint connector (CAN5) terminal No.2 and camera-ECU connector terminal No.1 <RHD>
OK: Continuity (2 Ω or less)
(7)Continuity between joint connector (CAN5) terminal No.13 and camera-ECU connector terminal No.21 <RHD>
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 camera-ECU connector.

STEP 3. Resistance measurement at camera-ECU connector.


caution A digital multimeter should be used.
(1)Remove the camera-ECU, and measure at the equipment side.
(2)Resistance between camera-ECU connector terminal Nos.1 and 21
OK: 1 kΩ or more

Q. Is the check result normal?

Power supply to the camera-ECU may be suspected. Diagnose the multi around monitor. Refer to GROUP 54A - Troubleshooting .
Replace the camera-ECU.