Diagnosis Item 3: Diagnose shorts between CAN_H and L lines.

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 M.U.T.-III judges a short between CAN_H and CAN_L line when all data from ECU cannot be received while checking periodically sent data from each ECU even if the voltage is normal.

TROUBLE JUDGEMENT CONDITIONS

The M.U.T.-III judges the trouble when it is impossible to send and receive the all ECU periodically sent data and the voltage of CAN_H and CAN_L line is 4.0 volts or less and 1.0 volt or more.

TROUBLESHOOTING HINTS

Malfunction of the wiring harness

note

The M.U.T.-III cannot receive all the periodically sent data from each ECU by the open circuit of harness between the diagnosis connector, the joint connector (CAN1) and the joint connector (CAN2). In addition, the M.U.T.-III measures the voltage itself and shows 2.5 volts due to the open circuit of harness. Therefore, it is judged as a short between CAN_H and CAN_L line.

Malfunction of the connector
Malfunction of each ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: D-230 intermediate connector

caution

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

Q. Is the check result normal?

	Go to Step 2.

	Repair the defective connector.

STEP 2. Resistance measurement at D-230 intermediate connector.

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 its male-side intermediate connector (at the instrument panel 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 D-230 intermediate connector terminal Nos.12 and 13
OK: 120 ± 20 Ω

Q. Is the check result normal?

	<Within 120 ± 20 Ω> Go to Step 3.

	<Not within 120 ± 20 Ω> Go to Step 14.

STEP 3. Connector check: D-22 joint connector (CAN2)

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 4.

	Repair a defective connector or replace the joint connector.

STEP 4. Resistance measurement at D-22 joint connector (CAN2).

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 (CAN2), 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 D-22 joint connector (CAN2) terminal Nos.6 and 11
OK: 120 ± 20 Ω

caution

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

Q. Is the check result normal?

	YES <petrol powered vehicles without ASTC> : <Within 120 ± 20 Ω> Go to Step 10.

	YES <diesel powered vehicles without ASTC-M/T> : <Within 120 ± 20 Ω> Go to Step 10.

	YES <diesel powered vehicles without ASTC-A/T> : <Within 120 ± 20 Ω> Go to Step 8.

	YES <vehicles with ASTC> : <Within 120 ± 20 Ω> Go to Step 6.

	NO (the check result is not normal.) : <Not within 120 ± 20 Ω> Go to Step 5.

STEP 5. Resistance measurement at D-40 resistor connector <vehicles without ASTC> or D-223 ASTC-ECU connector <vehicles with ASTC>.

caution

A digital multimeter should be used. For details refer to

(1)Remove the resistor <vehicles without ASTC> or ASTC-ECU <vehicles with resistor>, and measure at the equipment side.

(2)Resistance at D-40 resistor connector terminal Nos.1 and 2 <vehicles without ASTC>
OK: 120 ± 20 Ω

(3)Resistance at D-223 ASTC-ECU connector terminal Nos.83 and 84 <vehicles with ASTC>
OK: 120 ± 20 Ω

Q. Is the check result normal?

	<Within 120 ± 20 Ω> Repair the wiring harness between joint connector (CAN2) and the resistor connector <vehicles without ASTC> or ASTC-ECU connector <vehicles with ASTC>.

	<Not within 120 ± 20 Ω> Check the resistor connector <vehicles without ASTC> or ASTC-ECU connector <vehicles with ASTC>, and repair if necessary. If the resistor connector <vehicles without ASTC> or ASTC-ECU connector <vehicles with ASTC> is in good condition, replace the resistor <vehicles without ASTC> or hydraulic unit assembly <vehicles with ASTC>.

STEP 6. Resistance measurement at D-22 joint connector (CAN2).

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 D-22 joint connector (CAN2) terminal Nos.1 and 4
OK: 1 kΩ or more

caution

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

Q. Is the check result normal?

	YES <petrol powred vehicles or diesel powered vehicles-M/T> : <1 kΩ or more> Go to Step 10.

	YES <diesel powered vehicles-A/T> : <1 kΩ or more> Go to Step 8.

	NO (the check result is not normal.) : <Less than 1 kΩ> Go to Step 7.

STEP 7. Resistance measurement at D-18 G and yaw rate sensor connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the G and yaw rate sensor, and measure at the equipment side.

(2)Resistance at D-18 G and yaw rate sensor connector terminal Nos.1 and 4
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN2) and the G and yaw rate sensor connector.

	<Less than 1 kΩ> Check the G and yaw rate sensor connector, and repair if necessary. If the G and yaw rate sensor connector is in good condition, replace the G and yaw rate sensor.

STEP 8. Resistance measurement at D-22 joint connector (CAN2).

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 (CAN2), 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 D-22 joint connector (CAN2) terminal Nos.8 and 10
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 D-39 A/T-ECU connector.

caution

A digital multimeter should be used. For details refer to

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

(2)Resistance at D-39 A/T-ECU connector terminal Nos.53 and 54
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN2) and the SRS-ECU connector.

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

STEP 10. Resistance measurement at D-22 joint connector (CAN2).

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 (CAN2), 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 D-22 joint connector (CAN2) terminal Nos.3 and 9
OK: 1 kΩ or more

caution

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

Q. Is the check result normal?

	YES <except 2800> : <1 kΩ or more> Go to Step 12.

	YES <2800> : <1 kΩ or more> Repair the wiring harness between joint connector (CAN2) and intermediate connector (D-230).

	NO (the check result is not normal.) : <Less than 1 kΩ> Go to Step 11.

STEP 11. Resistance measurement at D-24 SRS-ECU connector.

caution

A digital multimeter should be used. For details refer to

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

(2)Resistance at D-24 SRS-ECU connector terminal Nos.32 and 43
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN2) and the SRS-ECU connector.

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

STEP 12. Resistance measurement at D-22 joint connector (CAN2).

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 (CAN2), 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 D-22 joint connector (CAN2) terminal Nos.7 and 12
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 (CAN2) and intermediate connector (D-230).

	<Less than 1 kΩ> Go to Step 13.

STEP 13. Resistance measurement at D-215 <3200> or D-245 <3000-M/T, 3800-M/T> engine-ECU connector or D-216 engine-A/T-ECU connector <3000-A/T, 3800-A/T>.

caution

A digital multimeter should be used. For details refer to

(1)Remove the engine-ECU <3000-M/T, 3200, 3800-M/T> or engine-A/T-ECU <3000-A/T, 3800-A/T>, and measure at the equipment side.

(2)Resistance between D-245 engine-ECU connector terminal Nos.61 and 62 <3000-M/T, 3800-M/T>
OK: 1 kΩ or more

(3)Resistance between D-216 engine-A/T-ECU connector terminal Nos.61 and 62 <3000-A/T, 3800-A/T>
OK: 1 kΩ or more

(4)Resistance between D-215 engine-ECU connector terminal Nos.117 and 125 <3200>
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 (CAN2) and the engine-ECU <3000-M/T, 3200, 3800-M/T> or engine-A/T-ECU <3000-A/T, 3800-A/T>.

	<Less than 1 kΩ> Check the engine-ECU <3000-M/T, 3200, 3800-M/T> or engine-A/T-ECU <3000-A/T, 3800-A/T>, and repair if necessary. If the engine-ECU <3000-M/T, 3200, 3800-M/T> or engine-A/T-ECU <3000-A/T, 3800-A/T> is in good condition, replace the engine-ECU <3000-M/T, 3200, 3800-M/T> or engine-A/T-ECU <3000-A/T, 3800-A/T>.

STEP 14. Connector check: D-03 joint connector (CAN1)

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 15.

	Repair a defective connector or replace the joint connector.

STEP 15. Resistance measurement at D-03 joint connector (CAN1).

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 (CAN1), 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 D-03 joint connector (CAN1) terminal Nos.3 and 14 <LH drive vehicles>
OK: 1 kΩ or more

(5)Resistance between D-03 joint connector (CAN1) terminal Nos.1 and 12 <RH drive vehicles>
OK: 1 kΩ or more

caution

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

Q. Is the check result normal?

	YES <except vehicles for South Africa-3200> : <Within 120 ± 20 Ω> Go to Step 19.

	YES <vehicles for South Africa-3200> : <Within 120 ± 20 Ω> Go to Step 17.

	NO (the check result is not normal.) : <Not within 120 ± 20 Ω> Go to Step 16.

STEP 16. Resistance measurement at D-04 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 between D-04 combination meter connector terminal Nos.23 and 24
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 (CAN1) 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.

STEP 17. Resistance measurement at D-03 joint connector (CAN1).

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 (CAN1), 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 D-03 joint connector (CAN1) 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 19.

	<Less than 1 kΩ> Go to Step 18.

STEP 18. Resistance measurement at D-126 immobilizer-ECU connector.

caution

A digital multimeter should be used. For details refer to

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

(2)Resistance at D-126 immobilizer-ECU connector terminal Nos.3 and 4
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN1) and the immobilizer-ECU connector.

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

STEP 19. Resistance measurement at D-03 joint connector (CAN1).

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 (CAN1), 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 D-03 joint connector (CAN1) 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?

	YES <vehicles without centre display and ASTC> : <1 kΩ or more> Go to Step 25.

	YES <vehicles without centre display and without ASTC> : <1 kΩ or more> Go to Step 23.

	YES <vehicles with centre display> : <1 kΩ or more> Go to Step 21.

	NO (the check result is not normal.) : <Less than 1 kΩ> Go to Step 20.

STEP 20. Resistance measurement at D-420 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 at D-420 ETACS-ECU connector terminal Nos.72 and 73
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN1) and the ETACS-ECU connector.

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

STEP 21. Resistance measurement at D-03 joint connector (CAN1).

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 (CAN1), 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 D-03 joint connector (CAN1) 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?

	YES <vehicles without ASTC> : <1 kΩ or more> Go to Step 25.

	YES <vehicles with ASTC> : <1 kΩ or more> Go to Step 23.

	NO (the check result is not normal.) : <Less than 1 kΩ> Go to Step 22.

STEP 22. Resistance measurement at D-106 centre display connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the centre display, and measure at the equipment side.

(2)Resistance at D-106 centre display connector terminal Nos.6 and 7
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN1) and the centre display connector.

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

STEP 23. Resistance measurement at D-03 joint connector (CAN1).

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 (CAN1), 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 D-03 joint connector (CAN1) terminal Nos.2 and 13
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 25.

	<Less than 1 kΩ> Go to Step 24.

STEP 24. Resistance measurement at D-308 steering wheel sensor connector.

caution

A digital multimeter should be used. For details refer to

(1)Remove the steering wheel sensor, and measure at the equipment side.

(2)Resistance at D-308 steering wheel sensor connector terminal Nos.3 and 4
OK: 1 kΩ or more

Q. Is the check result normal?

	<1 kΩ or more> Repair the wiring harness between joint connector (CAN1) and the steering wheel sensor connector.

	<Less than 1 kΩ> Check the steering wheel sensor connector, and repair if necessary. If the steering wheel sensor connector is in good condition, replace the steering wheel sensor.

STEP 25. Resistance measurement at D-03 joint connector (CAN1).

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 joint connector (CAN1), 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 D-03 joint connector (CAN1) terminal Nos.3 and 14
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 (CAN1) and intermediate connector (D-230).

	<Less than 1 kΩ> Check the diagnosis connector, and repair if necessary. If the diagnosis connector is in good condition, repair the wiring harness between joint connector (CAN1) and the diagnosis connector.