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Diagnostic Item 3: Diagnose shorts in the ground to CAN bus line
 
 
cautionWhen servicing a CAN bus line, ground 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.
 
 
TROUBLE JUDGMENT CONDITIONS
The scan tool (scan tool (M.U.T.-III)) judges the trouble when it is impossible to receive the periodically sent data and the voltage of CAN_H or CAN_L line is less than 1.0 V.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the wiring harness
  • Malfunction of the connector
  • Malfunction of the ETACS-ECU
  • Malfunction of the combination meter
  • Malfunction of the SRS-ECU
  • Malfunction of the occupant classification-ECU
  • Malfunction of the KOS-ECU <Vehicles with KOS>
  • Malfunction of the OSS-ECU <Vehicles with KOS>
  • Malfunction of the auto A/C controller assembly (A/C-ECU) <Vehicles with automatic A/C>
  • Malfunction of the Steering wheel sensor
  • Malfunction of the EPS-ECU
  • Malfunction of the ASC-ECU
  • Malfunction of the transaxle control module (TCM) <CVT>
  • Malfunction of the engine control module (ECM)
  • Malfunction of the PTC heater control unit <ECU for signal reception only>
 
 
DIAGNOSIS
STEP 1. Check the CAN bus lines. Resistance measurement at data link connector.
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
noteThis inspection allows you to check that there is a short to ground in either CAN_H line or CAN_L line. Thus, in the following steps, check the CAN bus line that is defective.
(1) Disconnect engine control module (ECM) connector and ETACS-ECU connector, and measure the resistance at harness side of data link connector.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between data link connector terminal No.6 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between data link connector terminal No.14 (CAN_L) and body ground
OK: 1 kΩ or more
Is the check result normal?
<Both of the measurement results show 1 kΩ or more> Go to Step 39.
<Either of CAN_H line or CAN_L line the measurement results show less than 1 kΩ> Go to Step 2.
 
STEP 2. Check the CAN line. Resistance measurement at C-212 intermediate connector.
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect the C-212 intermediate connector, and measure at its female-side intermediate connector (at the front wiring harness side).
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between C-212 intermediate connector terminal No.17 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between C-212 intermediate connector terminal No.8 (CAN_L) and body ground
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Go to Step 16.
<Less than 1 kΩ > Go to Step 3.
 
STEP 3. Check the CAN line between joint connector (CAN2) and the engine control module (ECM). Resistance measurement at joint connector (CAN2).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN2) terminal No.11 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN2) terminal No.22 (CAN_L) and body ground
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Go to Step 4.
<Less than 1 kΩ > Repair the wiring harness between joint connector (CAN2) and the engine control module (ECM) connector.
 
STEP 4. Check the CAN line between joint connector (CAN2) and the transaxle control module (TCM). Resistance measurement at joint connector (CAN2).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN2) terminal No.7 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN2) terminal No.18 (CAN_L) and body ground
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Go to Step 7.
<Less than 1 kΩ > Go to Step 5.
 
STEP 5. scan tool (M.U.T.-III) CAN bus diagnostics [transaxle control module (TCM) connector disconnected]
(1) Disconnect transaxle control module (TCM) connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Check intermediate connector, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN2) and the transaxle control module (TCM) connector.
Check the transaxle control module (TCM) connector, and repair if necessary. If the transaxle control module (TCM) connector is in good condition, go to Step 6.
 
STEP 6. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the transaxle control module (TCM) connector, and repair if necessary. If the transaxle control module (TCM) connector is in good condition, replace the transaxle control module (TCM).
 
STEP 7. Check the CAN line between joint connector (CAN2) and the ASC-ECU. Resistance measurement at joint connector (CAN2).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN2) terminal No.9 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN2) terminal No.20 (CAN_L) and body ground
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Go to Step 10.
<Less than 1 kΩ > Go to Step 8.
 
STEP 8. scan tool (M.U.T.-III) CAN bus diagnostics [ASC-ECU connector disconnected]
(1) Disconnect ASC-ECU connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN2) and the ASC-ECU connector.
Check the ASC-ECU connector, and repair if necessary. If the ASC-ECU connector is in good condition, go to Step 9.
 
STEP 9. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the ASC-ECU connector, and repair if necessary. If the ASC-ECU connector is in good condition, replace the ASC-ECU.
 
STEP 10. Check the CAN line between joint connector (CAN2) and the EPS-ECU. Resistance measurement at joint connector (CAN2).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN2) terminal No.8 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN2) terminal No.19 (CAN_L) and body ground
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Go to Step 13.
<Less than 1 kΩ > Go to Step 11.
 
STEP 11. scan tool (M.U.T.-III) CAN bus diagnostics [EPS-ECU connector disconnected]
(1) Disconnect EPS-ECU connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN2) and the EPS-ECU connector.
Check the EPS-ECU connector, and repair if necessary. If the EPS-ECU connector is in good condition, go to Step 12.
 
STEP 12. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the EPS-ECU connector, and repair if necessary. If the EPS-ECU connector is in good condition, replace the EPS-ECU.
 
STEP 13. Check the CAN line between joint connector (CAN2) and the PTC heater control unit. Resistance measurement at joint connector (CAN2).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN2), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN2) terminal No.5 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN2) terminal No.16 (CAN_L) and body ground
OK: 1 kΩ or more
Is the check result normal?
<1 kΩ or more> Repair C-212 intermediate connector, or the wiring harness between joint connector (CAN2) and C-212 intermediate connector.
<Less than 1 kΩ > Go to Step 14.
 
STEP 14. scan tool (M.U.T.-III) CAN bus diagnostics [PTC heater control unit connector disconnected]
(1) Disconnect PTC heater control unit connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN2) and the PTC heater control unit connector.
Check the PTC heater control connector, and repair if necessary. If the PTC heater control connector is in good condition, go to Step 15.
 
STEP 15. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the PTC heater control connector, and repair if necessary. If the PTC heater control connector is in good condition, replace the PTC heater control.
 
STEP 16. Check CAN line between joint connector (CAN1) and the ETACS-ECU. Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.10 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.21 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Go to Step 17.
<Less than 1 kΩ > Repair the wiring harness between joint connector (CAN1) and the ETACS-ECU connector.
 
STEP 17. Check the CAN line between joint connector (CAN1) and the combination meter. Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.6 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.17 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Go to Step 20.
<Less than 1 kΩ > Go to Step 18.
 
STEP 18. scan tool (M.U.T.-III) CAN bus diagnostics [combination meter connector disconnected]
(1) Disconnect combination meter connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) and the combination meter connector.
Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, go to Step 19.
 
STEP 19. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, replace the combination meter.
 
STEP 20. Check the CAN line between joint connector (CAN1) and the SRS-ECU. Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.4 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.15 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Go to Step 23.
<Less than 1 kΩ > Go to Step 21.
 
STEP 21. scan tool (M.U.T.-III) CAN bus diagnostics [SRS-ECU connector disconnected]
(1) Disconnect SRS-ECU connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (scan tool (M.U.T.-III)) screen is as shown in the illustration.
Does scan tool (scan tool (M.U.T.-III)) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) and the SRS-ECU connector.
Check the SRS-ECU connector, and repair if necessary. If the SRS-ECU connector is in good condition, go to Step 22.
 
STEP 22. scan tool (scan tool (M.U.T.-III)) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (scan tool (M.U.T.-III)) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the SRS-ECU connector, and repair if necessary. If the SRS-ECU connector is in good condition, replace the SRS-ECU.
 
STEP 23. Check the CAN line between joint connector (CAN1) and the occupant classification-ECU. Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.1 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.12 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Go to Step 26.
<Less than 1 kΩ > Go to Step 24.
 
STEP 24. scan tool (M.U.T.-III) CAN bus diagnostics [occupant classification-ECU connector disconnected]
(1) Disconnect occupant classification-ECU connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) and the occupant classification-ECU connector.
Check the occupant classification-ECU connector, and repair if necessary. If the occupant classification-ECU connector is in good condition, go to Step 25.
 
STEP 25. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the occupant classification-ECU connector, and repair if necessary. If the occupant classification-ECU connector is in good condition, replace the occupant classification-ECU.
 
STEP 26. Check the CAN line between joint connector (CAN1) and the KOS-ECU. Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.11 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.22 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Go to Step 29.
<Less than 1 kΩ > Go to Step 27.
 
STEP 27. scan tool (M.U.T.-III) CAN bus diagnostics [KOS-ECU connector disconnected]
(1) Disconnect KOS-ECU connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) and the KOS-ECU connector.
Check the KOS-ECU connector, and repair if necessary. If the KOS-ECU connector is in good condition, go to Step 28.
 
STEP 28. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the KOS-ECU connector, and repair if necessary. If the KOS-ECU connector is in good condition, replace the KOS-ECU.
 
STEP 29. Check the CAN line between joint connector (CAN1) and the OSS-ECU. Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.5 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.16 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Go to Step 32.
<Less than 1 kΩ > Go to Step 30.
 
STEP 30. scan tool (M.U.T.-III) CAN bus diagnostics [OSS-ECU connector disconnected]
(1) Disconnect OSS-ECU connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) and the OSS-ECU connector.
Check the OSS-ECU connector, and repair if necessary. If the OSS-ECU connector is in good condition, go to Step 31.
 
STEP 31. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the OSS-ECU connector, and repair if necessary. If the OSS-ECU connector is in good condition, replace the OSS-ECU.
 
STEP 32. Check the CAN line between joint connector (CAN1) and the auto A/C controller assembly (A/C-ECU). Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.7 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.18 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Go to Step 35.
<Less than 1 kΩ > Go to Step 33.
 
STEP 33. scan tool (M.U.T.-III) CAN bus diagnostics [auto A/C controller assembly (A/C-ECU) connector disconnected]
(1) Disconnect auto A/C controller assembly (A/C-ECU) connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) and the auto A/C controller assembly (A/C-ECU) connector.
Check the auto A/C controller assembly (A/C-ECU) connector, and repair if necessary. If the auto A/C controller assembly (A/C-ECU) connector is in good condition, go to Step 34.
 
STEP 34. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the auto A/C controller assembly (A/C-ECU) connector, and repair if necessary. If the auto A/C controller assembly (A/C-ECU) connector is in good condition, replace the auto A/C controller assembly (A/C-ECU).
 
STEP 35. Check the CAN line between joint connector (CAN1) and the steering wheel sensor. Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.3 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.14 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Go to Step 38.
<Less than 1 kΩ > Go to Step 36.
 
STEP 36. scan tool (M.U.T.-III) CAN bus diagnostics [steering wheel sensor connector disconnected]
(1) Disconnect steering wheel sensor connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) and the steering wheel sensor connector.
Check the steering wheel sensor connector, and repair if necessary. If the steering wheel sensor connector is in good condition, go to Step 37.
 
STEP 37. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
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 38. Check the CAN line between joint connector (CAN1) and the data link connector. Resistance measurement at joint connector (CAN1).
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect joint connector (CAN1), and measure at the wiring harness side.
(2)
cautionWhen measuring the resistance, disconnect the negative battery terminal. For details refer to .
Ensure that the negative battery terminal is disconnected.
(3) Resistance between joint connector (CAN1) terminal No.8 (CAN_H) and body ground
OK: 1 kΩ or more
(4) Resistance between joint connector (CAN1) terminal No.19 (CAN_L) and body ground
OK: 1 kΩ or more
(5)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
Is the check result normal?
<1 kΩ or more> Repair the C-212 intermediate connector, or the wiring harness between joint connector (CAN1) and the C-212 intermediate connector.
<Less than 1 kΩ > Repair the data link connector, or the wiring harness between joint connector (CAN1) and the data link connector.
 
STEP 39. scan tool (M.U.T.-III) CAN bus diagnostics [engine control module (ECM) connector disconnected]
(1) Disconnect engine control module (ECM) connector and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
Go to Step 41.
Check the engine control module (ECM) connector, and repair if necessary. If the engine control module (ECM) connector is in good condition, go to Step 40.
 
STEP 40. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the engine control module (ECM) connector, and repair if necessary. If the engine control module (ECM) connector is in good condition, replace the engine control module (ECM).
 
STEP 41. scan tool (M.U.T.-III) CAN bus diagnostics [ETACS-ECU connector disconnected]
(1) Disconnect ETACS-ECU connector, and diagnose by using the scan tool (M.U.T.-III).
(2) Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen is as shown in the illustration.
Does scan tool (M.U.T.-III) screen correspond to the illustration?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, go to Step 42.
 
STEP 42. scan tool (M.U.T.-III) CAN bus diagnostics (retest the system)
Diagnose CAN bus lines, and check if scan tool (M.U.T.-III) screen shows normal state.
Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, replace the ETACS-ECU.