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DIAGNOSTIC ITEM 23: Short to power supply or ground, open circuit or line-to-line short in the CAN-B bus lines.
 
 
cautionWhen servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do so, a component connected to the CAN bus line may be damaged.

 
 
 
 
FUNCTION
If a short to power supply or ground, open circuit or line-to-line short is present at either CAN_H or CAN_L side on the CAN-B lines, this diagnosis result will be set.
 
 
TROUBLE JUDGMENT CONDITIONS
When CAN-B lines communication is normal, and diagnostic trouble code U0019 is set, the ETACS-ECU determines that there is a failure.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of the connector (short to power supply or ground in connector or improperly connected)
  • Malfunction of the wiring harness (short to power supply or ground, open circuit or line-to-line short in CAN bus lines)
  • Faulty ECU(s) (internal short to power supply or ground)
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Check the wiring harness between ETACS-ECU connector C-411 and body ground for a short to ground. Measure the resistance at ETACS-ECU connector C-411.
cautionDisconnect the negative battery terminal. For details refer to .
cautionA digital multimeter should be used. For details refer to .
cautionThe test wiring harness should be used. For details refer to .
(1) Disconnect ETACS-ECU connector C-411, and measure the voltage at the wiring harness side of ETACS-ECU connector.
(2) Measure the resistance between ETACS-ECU connector terminal 6 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between ETACS-ECU connector terminal 7 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
Go to Step 2.
Go to Step 10.
 
STEP 2. Check the wiring harness between joint connector (CAN1) C-05 and combination meter connector C-203 for a short to ground. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).
(2) Measure the resistance between joint connector (CAN1) terminal 7 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between joint connector (CAN1) terminal 18 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
(vehicles with KOS) : Go to Step 3.
(vehicles without KOS) : Go to Step 5.
Go to Step 36.
 
STEP 3. Check the wiring harness between joint connector (CAN1) C-05 and KOS-ECU connector C-10 for a short to ground. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).
(2) Measure the resistance between joint connector (CAN1) terminal 9 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between joint connector (CAN1) terminal 20 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
Go to Step 4.
Go to Step 37.
 
STEP 4. Check the wiring harness between joint connector (CAN1) C-05 and OSS-ECU connector C-14 for a short to ground. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).
(2) Measure the resistance between joint connector (CAN1) terminal 5 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between joint connector (CAN1) terminal 16 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
Go to Step 6.
Go to Step 38.
 
STEP 5. Check the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09 for a short to ground. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).
(2) Measure the resistance between joint connector (CAN1) terminal 9 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between joint connector (CAN1) terminal 20 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
Go to Step 6.
Go to Step 39.
 
STEP 6. Check the wiring harness between joint connector (CAN1) C-05 and SRS-ECU connector C-126 for a short to ground. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).
(2) Measure the resistance between joint connector (CAN1) terminal 10 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between joint connector (CAN1) terminal 21 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
Go to Step 7.
Go to Step 40.
 
STEP 7. Check the wiring harness between joint connector (CAN1) C-05 and occupant classification-ECU connector D-48-2 for a short to ground. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).
(2) Measure the resistance between joint connector (CAN1) terminal 4 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between joint connector (CAN1) terminal 15 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
Go to Step 8.
Go to Step 41.
 
STEP 8. Check the wiring harness between joint connector (CAN1) C-05 and A/C control panel connector C-216 for a short to ground. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the resistance at the wiring harness side of joint connector (CAN1).
(2) Measure the resistance between joint connector (CAN1) terminal 6 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between joint connector (CAN1) terminal 17 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
Go to Step 9.
Go to Step 42.
 
STEP 9. Check the wiring harness between joint connector (CAN1) C-05 and ETACS-ECU connector C-411 for a short to ground. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1) and ETACS-ECU connector C-411, and measure the resistance at the wiring harness side of joint connector (CAN1).
(2) Measure the resistance between joint connector (CAN1) terminal 11 and body ground.
OK: 1 kΩ or more
(3) Measure the resistance between joint connector (CAN1) terminal 22 and body ground.
OK: 1 kΩ or more
Do all the resistances measure 1 kΩ or more?
Go to Step 43.
Repair the wiring harness between joint connector (CAN1) C-103 and ETACS-ECU connector C-301.
 
STEP 10. Check the wiring harness between ETACS-ECU connector C-411 and body ground for a short to power supply. Measure the voltage at ETACS-ECU connector C-411.
(1) Disconnect ETACS-ECU connector C-411, and measure the voltage at the wiring harness side of ETACS-ECU connector.
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between ETACS-ECU connector terminal 6 and body ground.
OK: 4.7 volts or less
(4) Measure the voltage between ETACS-ECU connector terminal 7 and body ground.
OK: 4.7 volts or less
Do all the voltages measure 4.7 volts or less?
Go to Step 19.
Go to Step 11.
 
STEP 11. Check the wiring harness between joint connector (CAN1) C-05 and combination meter connector C-203 for a short to power supply. Measure the voltage at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).
(2) Connect the negative battery terminal.
(3) Turn the ignition switch to the ON position.
(4) Measure the voltage between joint connector (CAN1) terminal 7 and body ground.
OK: 4.7 volts or less
(5) Measure the voltage between joint connector (CAN1) terminal 18 and body ground.
OK: 4.7 volts or less
Do all the voltages measure 4.7 volts or less?
(vehicles with KOS) : Go to Step 12.
(vehicles without KOS) : Go to Step 14.
Go to Step 36.
 
STEP 12. Check the wiring harness between joint connector (CAN1) C-05 and KOS-ECU connector C-10 for a short to power supply. Measure the voltage at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between joint connector (CAN1) terminal 9 and body ground.
OK: 4.7 volts or less
(4) Measure the voltage between joint connector (CAN1) terminal 20 and body ground.
OK: 4.7 volts or less
Do all the voltages measure 4.7 volts or less?
Go to Step 13.
Go to Step 37.
 
STEP 13. Check the wiring harness between joint connector (CAN1) C-05 and OSS-ECU connector C-14 for a short to power supply. Measure the voltage at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between joint connector (CAN1) terminal 5 and body ground.
OK: 4.7 volts or less
(4) Measure the voltage between joint connector (CAN1) terminal 16 and body ground.
OK: 4.7 volts or less
Do all the voltages measure 4.7 volts or less?
Go to Step 15.
Go to Step 38.
 
STEP 14. Check the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09 for a short to power supply. Measure the voltage at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between joint connector (CAN1) terminal 9 and body ground.
OK: 4.7 volts or less
(4) Measure the voltage between joint connector (CAN1) terminal 20 and body ground.
OK: 4.7 volts or less
Do all the voltages measure 4.7 volts or less?
Go to Step 15.
Go to Step 39.
 
STEP 15. Check the wiring harness between joint connector (CAN1) C-05 and SRS-ECU connector C-126 for a short to power supply. Measure the voltage at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between joint connector (CAN1) terminal 10 and body ground.
OK: 4.7 volts or less
(4) Measure the voltage between joint connector (CAN1) terminal 21 and body ground.
OK: 4.7 volts or less
Do all the voltages measure 4.7 volts or less?
Go to Step 16.
Go to Step 40.
 
STEP 16. Check the wiring harness between joint connector (CAN1) C-05 and occupant classification-ECU connector D-48-2 for a short to power supply. Measure the voltage at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between joint connector (CAN1) terminal 4 and body ground.
OK: 4.7 volts or less
(4) Measure the voltage between joint connector (CAN1) terminal 15 and body ground.
OK: 4.7 volts or less
Do all the voltages measure 4.7 volts or less?
Go to Step 17.
Go to Step 41.
 
STEP 17. Check the wiring harness between joint connector (CAN1) C-05 and A/C control panel connector C-216 for a short to power supply. Measure the voltage at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and measure the voltage at the wiring harness side of joint connector (CAN1).
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between joint connector (CAN1) terminal 6 and body ground.
OK: 4.7 volts or less
(4) Measure the voltage between joint connector (CAN1) terminal 17 and body ground.
OK: 4.7 volts or less
Do all the voltages measure 4.7 volts or less?
Go to Step 18.
Go to Step 42.
 
STEP 18. Check the wiring harness between joint connector (CAN1) C-05 and ETACS-ECU connector C-411 for a short to power supply. Measure the voltage at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1) and ETACS-ECU connector C-411, and measure the voltage at the wiring harness side of joint connector (CAN1).
(2) Turn the ignition switch to the ON position.
(3) Measure the voltage between joint connector (CAN1) terminal 11 and body ground.
OK: 1.0 volts or less
(4) Measure the voltage between joint connector (CAN1) terminal 22 and body ground.
OK: 1.0 volts or less
Do all the voltages measure 1.0 volts or less?
Go to Step 43.
Repair the wiring harness between joint connector (CAN1) C-103 and ETACS-ECU connector C-411.
 
STEP 19. Check the wiring harness for line-to-line short. Measure the resistance at ETACS-ECU connector C-411
cautionDisconnect the negative battery terminal. For details refer to .
(1) Disconnect ETACS-ECU connector C-411, and check that there is continuity at the harness side of ETACS-ECU.
(2) Check that there is continuity between ETACS-ECU connector terminals 6 and 7.
OK: No continuity
Is the check result normal?
Go to Step 28.
Go to Step 20.
 
STEP 20. Check the wiring harness between joint connector (CAN1) C-05 and combination meter connector C-203 for line-to-line short. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).
(2) Check that there is continuity between joint connector (CAN1) terminals 4 and 15.
OK: No continuity
Is the check result normal?
(vehicles with KOS) : Go to Step 21.
(vehicles without KOS) : Go to Step 23.
Go to Step 36.
 
STEP 21. Check the wiring harness between joint connector (CAN1) C-05 and KOS-ECU connector C-10 for line-to-line short. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).
(2) Check that there is continuity between joint connector (CAN1) terminals 9 and 20.
OK: No continuity
Is the check result normal?
Go to Step 22.
Go to Step 37.
 
STEP 22. Check the wiring harness between joint connector (CAN1) C-05 and OSS-ECU connector C-14 for line-to-line short. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).
(2) Check that there is continuity between joint connector (CAN1) terminals 5 and 16.
OK: No continuity
Is the check result normal?
Go to Step 24.
Go to Step 38.
 
STEP 23. Check the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09 for line-to-line short. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).
(2) Check that there is continuity between joint connector (CAN1) terminals 9 and 20.
OK: No continuity
Is the check result normal?
Go to Step 24.
Go to Step 39.
 
STEP 24. Check the wiring harness between joint connector (CAN1) C-05 and SRS-ECU connector C-126 for line-to-line short. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).
(2) Check that there is continuity between joint connector (CAN1) terminals 10 and 21.
OK: No continuity
Is the check result normal?
Go to Step 25.
Go to Step 40.
 
STEP 25. Check the wiring harness between joint connector (CAN1) C-05 and occupant classification-ECU connector D-48-2 for line-to-line short. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).
(2) Check that there is continuity between joint connector (CAN1) terminals 4 and 15.
OK: No continuity
Is the check result normal?
Go to Step 26.
Go to Step 41.
 
STEP 26. Check the wiring harness between joint connector (CAN1) C-05 and A/C control panel connector C-216 for line-to-line short. Measure the resistance at joint connector (CAN1) C-05.
(1) Disconnect joint connector (CAN1), and check that there is continuity at the harness side of joint connector (CAN1).
(2) Check that there is continuity between joint connector (CAN1) terminals 6 and 17.
OK: No continuity
Is the check result normal?
Go to Step 27.
Go to Step 42.
 
STEP 27. Check the wiring harness between joint connector (CAN1) C-05 and ETACS-ECU connector C-411 for line-to-line short. Measure the resistance at joint connector (CAN1) C-05.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) and ETACS-ECU connector C-411, and check that there is continuity at the harness side of joint connector (CAN1).
(2) Check that there is continuity between joint connector (CAN1) terminals 11 and 22.
OK: No continuity
Is the check result normal?
Go to Step 43.
Repair the wiring harness between joint connector (CAN1) C-05 and ETACS-ECU connector C-411.
 
STEP 28. Check the wiring harness between joint connector (CAN1) C-05 and combination meter connector C-203 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and combination meter connector C-203, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.7) and combination meter connector C-203 (terminal No.14)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.18) and combination meter connector C-203 (terminal No.15)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and combination meter connector C-203 in good condition?
(vehicles with KOS) : Go to Step 29.
(vehicles without KOS) : Go to Step 31.
Repair the wiring harness between joint connector (CAN1) C-05 and combination meter connector C-203.
 
STEP 29. Check the wiring harness between joint connector (CAN1) C-05 and KOS-ECU connector C-10 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and KOS-ECU connector C-10, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.9) and KOS-ECU connector C-10 (terminal No.3)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.20) and KOS-ECU connector C-10 (terminal No.2)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and KOS-ECU connector C-10 in good condition?
Go to Step 30.
Repair the wiring harness between joint connector (CAN1) C-05 and KOS-ECU connector C-10.
 
STEP 30. Check the wiring harness between joint connector (CAN1) C-05 and OSS-ECU connector C-14 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and OSS-ECU connector C-14, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.5) and OSS-ECU connector C-14 (terminal No.1)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.16) and OSS-ECU connector C-14 (terminal No.14)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and OSS-ECU connector C-14 in good condition?
Go to Step 32.
Repair the wiring harness between joint connector (CAN1) C-05 and OSS-ECU connector C-14.
 
STEP 31. Check the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and WCM connector C-09, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.9) and WCM connector C-09 (terminal No.3)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.20) and WCM connector C-09 (terminal No.2)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09 in good condition?
Go to Step 32.
Repair the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09.
 
STEP 32. Check the wiring harness between joint connector (CAN1) C-05 and SRS-ECU connector C-126 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and SRS-ECU connector C-126, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.10) and SRS-ECU connector C-126 (terminal No.30)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.21) and SRS-ECU connector C-126 (terminal No.29)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and SRS-ECU connector C-126 in good condition?
Go to Step 33.
Repair the wiring harness between joint connector (CAN1) C-05 and SRS-ECU connector C-126.
 
STEP 33. Check the wiring harness between joint connector (CAN1) C-05 and occupant classification-ECU connector D-48-2 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and occupant classification-ECU connector D-48-2, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.4) and occupant classification-ECU connector D-48-2 (terminal No.24)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.15) and occupant classification-ECU connector D-48-2 (terminal No.25)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and occupant classification-ECU connector D-48-2 in good condition?
Go to Step 34.
Repair the wiring harness between joint connector (CAN1) C-05 and occupant classification-ECU connector D-48-2.
 
STEP 34. Check the wiring harness between joint connector (CAN1) C-05 and A/C control panel connector C-216 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and A/C-ECU connector C-210, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.6) and A/C control panel connector C-216 (terminal No.7)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.17) and A/C control panel connector C-216 (terminal No.8)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and A/C control panel connector C-216 in good condition?
Go to Step 35.
Repair the wiring harness between joint connector (CAN1) C-05 and A/C control panel connector C-216.
 
STEP 35. Check the wiring harness between joint connector (CAN1) C-05 and ETACS-ECU connector C-411 for open circuit.
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
(1) Disconnect joint connector (CAN1) C-05 and ETACS-ECU connector C-411, and check the wiring harness.
(2) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.11) and ETACS-ECU connector C-411 (terminal No.6)
OK: Continuity exists (2 ohms or less)
(3) Check the wiring harness between joint connector (CAN1) C-05 (terminal No.22) and ETACS-ECU connector C-411 (terminal No.7)
OK: Continuity exists (2 ohms or less)
Is the wiring harness between joint connector (CAN1) C-05 and ETACS-ECU connector C-411 in good condition?
Go to Step 43.
Repair the wiring harness between joint connector (CAN1) C-05 and ETACS-ECU connector C-411.
 
STEP 36. Using scan tool MB991958, diagnose the CAN bus line. (checking the combination meter for internal failure)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Disconnect combination meter connector C-203.
(2) Connect scan tool MB991958 to the data link connector. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(3) Turn the ignition switch to the "ON" position.
(4) Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
OK: The display of the scan tool MB991958 is as shown in the figure.
Does scan tool MB991958 screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) C-05 and combination meter connector C-203.
Check combination meter connector C-203, and repair if necessary. If the combination meter connector is in good condition, replace the combination meter.
 
STEP 37. Using scan tool MB991958, diagnose the CAN bus line. (checking the KOS-ECU for internal failure)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Disconnect KOS-ECU connector C-10.
(2) Connect scan tool MB991958 to the data link connector. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(3) Turn the ignition switch to the "ON" position.
(4) Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
OK: The display of the scan tool MB991958 is as shown in the figure.
Does scan tool MB991958 screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) C-05 and KOS-ECU connector C-10.
Check KOS-ECU connector C-10, and repair if necessary. If the KOS-ECU connector is in good condition, replace the KOS-ECU.
 
STEP 38. Using scan tool MB991958, diagnose the CAN bus line. (checking the OSS-ECU for internal failure)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Disconnect OSS-ECU connector C-14.
(2) Connect scan tool MB991958 to the data link connector. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(3) Turn the ignition switch to the "ON" position.
(4) Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
OK: The display of the scan tool MB991958 is as shown in the figure.
Does scan tool MB991958 screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) C-05 and OSS-ECU connector C-14.
Check OSS-ECU connector C-14, and repair if necessary. If the OSS-ECU connector is in good condition, replace the OSS-ECU.
 
STEP 39. Using scan tool MB991958, diagnose the CAN bus line. (checking the WCM for internal failure)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Disconnect WCM connector C-09.
(2) Connect scan tool MB991958 to the data link connector. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(3) Turn the ignition switch to the "ON" position.
(4) Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
OK: The display of the scan tool MB991958 is as shown in the figure.
Does scan tool MB991958 screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) C-05 and WCM connector C-09.
Check WCM connector C-09, and repair if necessary. If the WCM connector is in good condition, replace the WCM.
 
STEP 40. Using scan tool MB991958, diagnose the CAN bus line. (checking the SRS-ECU for internal failure)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Disconnect SRS-ECU connector C-126.
(2) Connect scan tool MB991958 to the data link connector. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(3) Turn the ignition switch to the "ON" position.
(4) Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
OK: The display of the scan tool MB991958 is as shown in the figure.
Does scan tool MB991958 screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) C-05 and SRS-ECU connector C-126.
Check SRS-ECU connector C-126, and repair if necessary. If the SRS-ECU connector is in good condition, replace the SRS-ECU.
 
STEP 41. Using scan tool MB991958, diagnose the CAN bus line. (checking the occupant classification-ECU for internal failure)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Disconnect occupant classification-ECU connector D-48-2.
(2) Connect scan tool MB991958 to the data link connector. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(3) Turn the ignition switch to the "ON" position.
(4) Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
OK: The display of the scan tool MB991958 is as shown in the figure.
Does scan tool MB991958 screen correspond to the illustration?
Check intermediate connectors C-17, and repair if necessary. If the intermediate connector is in good condition, repair the wiring harness between joint connector (CAN1) C-05 and occupant classification-ECU connector D-48-2.
Check occupant classification-ECU connector D-48-2, and repair if necessary. If the occupant classification-ECU connector is in good condition, replace the occupant classification-ECU.
 
STEP 42. Using scan tool MB991958, diagnose the CAN bus line. (checking the A/C control panel for internal failure)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Disconnect A/C control panel connector C-216.
(2) Connect scan tool MB991958 to the data link connector. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(3) Turn the ignition switch to the "ON" position.
(4) Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
OK: The display of the scan tool MB991958 is as shown in the figure.
Does scan tool MB991958 screen correspond to the illustration?
Repair the wiring harness between joint connector (CAN1) C-05 and A/C control panel connector C-216.
Check A/C control panel connector C-216, and repair if necessary. If the A/C control panel connector is in good condition, replace the A/C control panel.
 
STEP 43. Using scan tool MB991958, diagnose the CAN bus line. (trouble symptom check)
cautionStrictly observe the specified wiring harness repair procedure. For details refer to .
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose CAN bus lines, and check if the scan tool MB991958 screen is as shown in the figure.
OK: The display of the scan tool MB991958 is as shown in the figure.
Does scan tool MB991958 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 C-411, and repair if necessary. If the ETACS-ECU connector is in good condition, replace the ETACS-ECU.