Code No.04 Communication Error with Sunroof-ECU <vehicles with sunroof>






















caution If diagnosis code No.04 is set in the ETACS-ECU, diagnose the CAN bus lines.
note When the diagnosis codes relating to the CAN communication error are set, make sure of the vehicle equipment. When the vehicle is not equipped with the system the SWS communicates to, the diagnosis code is always set. This is not abnormal.

TROUBLE JUDGMENT
The ETACS-ECU communicates with the sunroof motor assembly (sunroof-ECU) through the SWS communication line. If there is any trouble in that communication, diagnosis code No.04 will be set.
note For vehicles without sunroof, diagnosis code No.04 does not mean that there is a problem.

COMMENTS ON TROUBLE SYMPTOM
The sunroof motor assembly (sunroof-ECU), the ETACS-ECU, connector(s), or wiring harness between the two may be defective.

PROBABLE CAUSES

  • Malfunction of the sunroof motor assembly (sunroof-ECU)
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54D - Troubleshooting ).

STEP 2.Check whether the diagnosis code is reset.
Check again if the diagnosis code is set.
(1)Erase the diagnosis code.
(2)Ignition switch: LOCK (OFF) position to ON
(3)On completion, check that the diagnosis code is not reset.

Q. Is the diagnosis code set?
Go to Step 3.
If a trouble is solved, it is determined that there is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points ).

STEP 3. Connector check: E-03 sunroof motor assembly connector

Q. Is the check result normal?
Go to Step 4.
Repair the defective connector.

STEP 4. Voltage measurement at E-03 sunroof motor assembly connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Voltage between E-03 sunroof motor assembly connector terminal No.1 and body earth
(3)OK: System voltage

Q. Is the check result normal?
Go to Step 6.
Go to Step 5.

STEP 5. Check the wiring harness between E-03 sunroof motor assembly connector terminal No.1 and fusible link (4).
note Prior to the wiring harness inspection, check intermediate connectors D-130, D-238, and repair if necessary.

  • Check the power supply line for open circuit.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points ).
Repair the wiring harness.

STEP 6. Voltage measurement at E-03 sunroof motor assembly connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Turn the ignition switch to the ON position.
(3)Voltage between E-03 sunroof motor assembly connector terminal No.2 and body earth
OK: System voltage

Q. Is the check result normal?
Go to Step 8.
Go to Step 7.

STEP 7. Check the wiring harness between E-03 sunroof motor assembly connector terminal No.2 and ignition switch (IG2).
note Prior to the wiring harness inspection, check intermediate connector D-130, junction block connectors D-403 and D-410, and repair if necessary.

  • Check the power supply line to the ignition switch (IG2) for open circuit.

Q. Is the check result normal?
Refer to GROUP 54A - Ignition switch .
Repair the wiring harness.

STEP 8. Resistance measurement at E-03 sunroof motor assembly connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Continuity between E-03 sunroof motor assembly connector terminal No.5 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Go to Step 10.
Go to Step 9.

STEP 9. Check the wiring harness between E-03 sunroof motor assembly connector terminal No.5 and body earth.

  • Check the earth wires for open circuit.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use troubleshooting/Inspection Service Points ).
Repair the wiring harness.

STEP 10. Connector check: D-420 ETACS-ECU connector

Q. Is the check result normal?
Go to Step 11.
Repair the defective connector.

STEP 11. Check the wiring harness between E-03 sunroof motor assembly connector terminal No.10 and D-420 ETACS-ECU connector terminal No.59.
note Prior to the wiring harness inspection, check intermediate connector D-130, and repair if necessary.

  • Check the communication lines for open and short circuit.

Q. Is the check result normal?
Go to Step 12.
Repair the wiring harness.

STEP 12. Check whether the diagnosis code is reset.
Replace the sunroof motor assembly (sunroof-ECU), and then check that the diagnosis code is not reset to the ETACS-ECU.
(1)Replace the sunroof motor assembly (sunroof-ECU).
(2)Erase the diagnosis code.
(3)Ignition switch: LOCK (OFF) position to ON
(4)On completion, check that diagnosis code No.04 is not reset.

Q. Is diagnosis code No.04 set?
Replace the ETACS-ECU.
The procedure is complete.