Diagnosis Item 8: Diagnose shorts between CAN_H and L lines (CAN-C-Mid).

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.
When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in GROUP 54A, Immobilizer System - How to Register Key ID .)

TROUBLE JUDGEMENT

When all of the following conditions are met, the M.U.T.-III determines that a short circuit is present between CAN_L and CAN_H lines.

The M.U.T.-III cannot receive the periodic transmission data from any ECUs.
The voltage between CAN-C-Mid (CAN_L and CAN_H lines) is 1.0 V or more, 4.0 V or less.
The resistance at CAN-C-Mid (CAN_L and CAN_H lines) is 2 Ω or less.

TROUBLESHOOTING HINTS

Malfunction of the wiring harness
Malfunction of the connector
Malfunction of the ETACS-ECU
Malfunction of the A/C-ECU
Malfunction of the KOS-ECU <Vehicles with KOS>
Malfunction of the OSS-ECU <Vehicles with OSS>
Malfunction of the CAN box unit <vehicles with MMCS>
Malfunction of the radio and CD player <vehicles with radio and CD player>
Malfunction of the corner sensor/back sensor-ECU <vehicles with reversing sensor system>
Malfunction of the electric tailgate control unit <vehicles with electric tailgate>
Malfunction of the combination meter

DIAGNOSIS PROCEDURE

STEP 1. Connector check: joint connector (CAN5)

caution

The strand end of the twist wire should be within 10 cm from the connector. For details refer to

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 a defective connector or replace the joint connector.

STEP 2. Resistance measurement at joint connector (CAN5).

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect the 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.11 and 22
OK: 120 ± 20 Ω

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<Within 120 ± 20 Ω> Go to Step 4.

	NO : <Not within 120 ± 20 Ω> Go to Step 3.

STEP 3. Resistance measurement at ETACS-ECU connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the ETACS-ECU, and measure at the equipment side.

(2)Resistance between ETACS-ECU connector terminal Nos.16 and 17
OK: 120 ± 20 Ω

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<Within 120 ± 20 Ω> Repair the wiring harness between joint connector (CAN5) and the ETACS-ECU connector.

	<Not within 120 ± 20 Ω> Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, replace the ETACS-ECU.

STEP 4. Resistance measurement at joint connector (CAN5).

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect the 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.6 and 17
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 6.

	<Less than 1 kΩ> Go to Step 5.

STEP 5. Resistance measurement at A/C-ECU connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the A/C-ECU, and measure at the equipment side.

(2)Resistance between A/C-ECU connector terminal Nos.31 and 32
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN5) and the A/C-ECU connector.

	<Less than 1 kΩ> Check the A/C-ECU connector, and repair if necessary. If the A/C-ECU connector is in good condition, replace the A/C-ECU.

STEP 6. Resistance measurement at joint connector (CAN5).

note

Steps 6 and 7 are only for vehicles with electric tailgate. On vehicles without it, go to Step 8

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect the 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.8 and 19
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 8.

	<Less than 1 kΩ> Go to Step 7.

STEP 7. Resistance measurement at electric tailgate control unit connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the electric tailgate control unit, and measure at the equipment side.

(2)Resistance between electric tailgate control unit connector terminal Nos.7 and 8
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Check the intermediate connector, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN5) and the electric tailgate control unit connector.

	<Less than 1 kΩ> Check the electric tailgate control unit connector, and repair if necessary. If the electric tailgate control unit connector is in good condition, replace the electric tailgate control unit.

STEP 8. Resistance measurement at joint connector (CAN5).

note

Steps 8 and 9 are only for vehicles with reversing sensor system. On vehicles without it, go to Step 10

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect the 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.4 and 15
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 10.

	<Less than 1 kΩ> Go to Step 9.

STEP 9. Resistance measurement at corner sensor/back sensor-ECU connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the corner sensor/back sensor-ECU, and measure at the equipment side.

(2)Resistance between corner sensor/back sensor-ECU connector terminal Nos.19 and 20
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN5) and the corner sensor/back sensor-ECU connector.

	<Less than 1 kΩ> Check the corner sensor/back sensor-ECU connector, and repair if necessary. If the corner sensor/back sensor-ECU connector is in good condition, replace the corner sensor/back sensor-ECU.

STEP 10. Resistance measurement at joint connector (CAN5).

note

Steps 10 and 11 are only for vehicles with radio and CD player system. On vehicles without it, go to Step 12

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect joint connector (CAN5), 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.7 and 18
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 12.

	<Less than 1 kΩ> Go to Step 11.

STEP 11. Resistance measurement at radio and CD player connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the radio and CD player, and measure at the equipment side.

(2)Resistance at radio and CD player connector terminal Nos.3 and 13
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN5) and the radio and CD player connector.

	<Less than 1 kΩ> Check the radio and CD player connector, and repair if necessary. If the radio and CD player connector is in good condition, replace the radio and CD player.

STEP 12. Resistance measurement at joint connector (CAN5).

note

Steps 12 and 13 are only for vehicles with MMCS. On vehicles without it, go to Step 14

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect joint connector (CAN5), 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.3 and 14 <CAN box unit>
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

(5)Resistance between joint connector (CAN5) terminal Nos.14 and 13 <multivision display>
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 14.

	<Less than 1 kΩ> Go to Step 13.

STEP 13. Resistance measurement at CAN box unit connector and multivision display connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the CAN box unit and multivision display, and measure at the equipment side.

(2)Resistance at CAN box unit connector terminal Nos.13 and 14 <CAN box unit>
OK: 1 kΩ or more

(3)Resistance at multivision display connector terminal Nos.14 and 13 <multivision display>
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN5) and the CAN box unit connector and multivision display connector.

	<Less than 1 kΩ> Check the CAN box unit connector and multivision display connector, and repair if necessary. If the CAN box unit connector and multivision display connector is in good condition, replace the CAN box unit and multivision display.

STEP 14. Resistance measurement at joint connector (CAN5).

note

Steps 14 and 15 are only for vehicles with OSS. On vehicles without it, go to Step 16

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect joint connector (CAN5), 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.10 and 21
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 16.

	<Less than 1 kΩ> Go to Step 15.

STEP 15. Resistance measurement at OSS-ECU connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the OSS-ECU, and measure at the equipment side.

(2)Resistance at OSS-ECU connector terminal Nos.1 and 14
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN5) and the OSS-ECU connector.

	<Less than 1 kΩ> Check the OSS-ECU connector, and repair if necessary. If the OSS-ECU connector is in good condition, replace the OSS-ECU.

STEP 16. Resistance measurement at joint connector (CAN5).

note

Steps 16 and 17 are only for vehicles with KOS. On vehicles without it, go to Step 18

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect joint connector (CAN5), 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.5 and 16
OK: 1 kΩ or more

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<1 kΩ or more> Go to Step 18.

	<Less than 1 kΩ> Go to Step 17.

STEP 17. Resistance measurement at KOS-ECU connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the KOS-ECU, and measure at the equipment side.

(2)Resistance at KOS-ECU connector terminal Nos.2 and 3
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN5) and the KOS-ECU connector.

	<Less than 1 kΩ> Check the KOS-ECU connector, and repair if necessary. If the KOS-ECU connector is in good condition, replace the KOS-ECU.

STEP 18. Resistance measurement at joint connector (CAN5).

caution

A digital multimeter should be used. For details refer to

caution

The test wiring harness should be used. For details refer to

(1)Disconnect joint connector (CAN5), 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. For details refer to

Ensure that the negative battery terminal is disconnected.

(4)Resistance between joint connector (CAN5) terminal Nos.9 and 20
OK: 120 ± 20 Ω

caution

Strictly observe the specified wiring harness repair procedure. For details refer to

Q. Is the check result normal?

	<Within 120 ± 20 Ω> The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).

	<Not within 120 ± 20 Ω> Go to Step 19.

STEP 19. Resistance measurement at combination meter connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the combination meter, and measure at the equipment side.

(2)Resistance at combination meter connector terminal Nos.14 and 15
OK: 120 ± 20 Ω

Q. Is the check result normal?

	<Within 120 ± 20 Ω> Repair the wiring harness between joint connector (CAN5) and the combination meter connector.

	<Not within 120 ± 20 Ω> Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, replace the combination meter.