Diagnostic Item 16: Diagnose CAN bus lines thoroughly <Vehicles for Hong Kong and Singapore>

TROUBLE JUDGMENT

COMMENTS ON TROUBLE SYMPTOM

POSSIBLE CAUSES

• Damaged harness wires and connectors
  
• Malfunction of the ETACS-ECU
  
• Malfunction of the combination meter
  
• Malfunction of the A/C-ECU
  
• Malfunction of the ABS-ECU
  
• Malfunction of the engine-A/T-ECU
  

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.

caution A digital multimeter should be used. For details refer to .

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

(1)Measure at the diagnosis connector wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-126 diagnosis connector terminal Nos.6 and 14 Q. How much resistance is measured? 2 Ω or less : Diagnose the lines between the CAN_L and H for short circuit. Refer to . No continuity : Diagnose the terminator resistors at both ends. Refer to . More than 2 Ω (i.e. continuity exists) : Go to Step 3.

note When checking A-07 joint connector (CAN1), disassemble and check the engine compartment relay box by referring to .

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 is not damaged. Q. Is the check result normal? Go to Step 4. Repair a defective connector or replace the joint connector (front wiring harness assembly).

(1)Disconnect the joint connector (CAN1), and check by using the M.U.T.-III.

(2)Check that the M.U.T.-III indications correspond to the illustration. Q. Is the check result normal? <M.U.T.-III indications correspond to the illustration> Go to Step 14. <M.U.T.-III indications do not correspond to the illustration> Go to Step 5.

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 is not damaged. Q. Is the check result normal? Go to Step 6. Repair a defective connector or replace the joint connector.

(1)Disconnect the combination meter connector, and diagnose by using the M.U.T.-III.

(2)Check that the M.U.T.-III indications correspond to the illustration. Q. Is the check result normal? <M.U.T.-III indications correspond to the illustration> Go to Step 7. <M.U.T.-III indications do not correspond to the illustration> 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 joint connector (CAN2) and the combination meter connector, and measure at the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-09 joint connector (CAN2) terminal No.6 and C-02 combination meter connector terminal No.24 OK: 2 Ω or less

(5)Continuity between C-09 joint connector (CAN2) terminal No.17 and C-02 combination meter connector terminal No.23 OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the resistances measure 2 Ω or less> Power supply to the combination meter may be suspected. Diagnose the combination meter. Refer to . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN2) and the combination meter 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 9. Repair the defective connector.

(1)Disconnect the A/C-ECU connector, and diagnose by using the M.U.T.-III.

(2)Check that the M.U.T.-III indications correspond to the illustration. Q. Is the check result normal? <M.U.T.-III indications correspond to the illustration> Go to Step 10. <M.U.T.-III indications do not correspond to the illustration> Go to Step 11.

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 (CAN2) and the A/C-ECU connector, and measure at the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-09 joint connector (CAN2) terminal No.8 and C-106 A/C-ECU connector terminal No.8 OK: 2 Ω or less

(5)Continuity between C-09 joint connector (CAN2) terminal No.19 and C-106 A/C-ECU connector terminal No.9 OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the resistances measure 2 Ω or less> Power supply to the A/C-ECU may be suspected. Diagnose the air conditioner system. Refer to . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between the joint connector (CAN2) and the A/C-ECU 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 12. Repair the defective connector.

(1)Disconnect the ETACS-ECU connector, and diagnose by using the M.U.T.-III.

(2)Check that the M.U.T.-III indications correspond to the illustration. Q. Is the check result normal? <M.U.T.-III indications correspond to the illustration> Go to Step 13. <M.U.T.-III indications do not correspond to the illustration> 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 the joint connector (CAN2) and the ETACS-ECU connector, and measure at the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-09 joint connector (CAN2) terminal No.5 and C-221 ETACS-ECU connector terminal No.72 OK: 2 Ω or less

(5)Continuity between C-09 joint connector (CAN2) terminal No.16 and C-221 ETACS-ECU connector terminal No.73 OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the resistances measure 2 Ω or less> Power supply to the ETACS-ECU may be suspected. Diagnose the SWS. Refer to . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between the joint connector (CAN2) and the ETACS-ECU 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 15. Repair the defective connector.

(1)Disconnect the engine-A/T-ECU connector, and diagnose by using the M.U.T.-III.

(2)Check that the M.U.T.-III indications correspond to the illustration. Q. Is the check result normal? <M.U.T.-III indications correspond to the illustration> Go to Step 16. <M.U.T.-III indications do not correspond to the illustration> Go to Step 19.

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 17. Repair the defective connector.

note When checking A-07 joint connector (CAN1), disassemble and check the engine compartment relay box by referring to .

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 the intermediate connector, and measure at the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between A-16 intermediate connector terminal No.6 and A-07 joint connector (CAN1) terminal No.6 OK: 2 Ω or less

(5)Continuity between A-16 intermediate connector terminal No.12 and A-07 joint connector (CAN1) terminal No.3 OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the voltages measure 2 Ω or less> Go to Step 18 . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN1) and the 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 engine-A/T-ECU connector and the intermediate connector, and measure at the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between A-16 intermediate connector terminal No.6 and C-112 engine-A/T-ECU connector terminal No.61. OK: 2 Ω or less

(5)Continuity between A-16 intermediate connector terminal No.12 and C-112 engine-A/T-ECU connector terminal No.62. OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the resistances measure 2 Ω or less> Power supply to the engine-A/T-ECU may be suspected. Diagnose the engine control system. Refer to . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between the engine-A/T-ECU connector and the joint connector (CAN1).

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 20. Repair the defective connector.

(1)Disconnect the ABS-ECU connector, and diagnose by using the M.U.T.-III.

(2)Check that the M.U.T.-III indications correspond to the illustration. Q. Is the check result normal? <M.U.T.-III indications correspond to the illustration> Go to Step 21. <M.U.T.-III indications do not correspond to the illustration> Go to Step 22.

note When checking A-07 joint connector (CAN1), disassemble and check the engine compartment relay box by referring to .

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 the ABS-ECU connector, and measure at the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between A-07 joint connector (CAN1) terminal No.2 and A-03 ABS-ECU connector terminal No.21 OK: 2 Ω or less

(5)Continuity between A-07 joint connector (CAN1) terminal No.5 and A-03 ABS-ECU connector terminal No.23 OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the resistances measure 2 Ω or less> Power supply to the ABS-ECU may be suspected. Diagnose the ABS system. Refer to . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between the joint connector (CAN1) and the ABS-ECU connector.

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 is not damaged. Q. Is the check result normal? Go to Step 23. Repair a defective connector or replace the joint 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 24. Repair the defective connector.

note When checking A-07 joint connector (CAN1), disassemble and check the engine compartment relay box by referring to .

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 the intermediate connector, and measure at the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-125 intermediate connector terminal No.26 and A-07 joint connector (CAN1) terminal No.4 OK: 2 Ω or less

(5)Continuity between C-125 intermediate connector terminal No.27 and A-07 joint connector (CAN1) terminal No.1 OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the voltages measure 2 Ω or less> Go to Step 25 . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN1) and the 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 joint connector (CAN2) and the intermediate connector, and measure at the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-125 intermediate connector terminal No.26 and C-09 joint connector (CAN2) terminal No.11 OK: 2 Ω or less

(5)Continuity between C-125 intermediate connector terminal No.27 and C-09 joint connector (CAN2) terminal No.22 OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the voltages measure 2 Ω or less> Go to Step 26 . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN2) and the 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 the wiring harness side. (2)Ignition switch: OFF (LOCK) (3) caution When measuring the resistance, disconnect the negative battery terminal. For details refer to . Ensure that the negative battery terminal is disconnected.

(4)Continuity between C-09 joint connector (CAN2) terminal No.7 and C-126 diagnosis connector terminal No.6 OK: 2 Ω or less

(5)Continuity between C-09 joint connector (CAN2) terminal No.18 and C-126 diagnosis connector terminal No.14 OK: 2 Ω or less caution Strictly observe the specified wiring harness repair procedure. For details refer to . Q. Are the check results normal? <All the resistances measure 2 Ω or less> Diagnostics item 9: Diagnose shorts between CAN_L and CAN_H lines. Refer to . <Either or all of the resistances measure more than 2 Ω> Repair the wiring harness between joint connector (CAN1) and the diagnosis connector.