[54D] SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR <Except for Hong Kong spec.> - - DIAGNOSTIC TROUBLE CODE PROCEDURES - Diagnosis code 21: Short circuit in SWS communication linePRINT PAGE / INDEX / PRIOR / NEXT
Diagnosis code 21: Short circuit in SWS communication line
 CAUTION
 Whenever the ECU is replaced, ensure that the communication circuit is normal.
COMMENTS ON TROUBLE SYMPTOM
If the SWS communication line voltage is kept at low level for 0.3 second, the diagnosis code will be set. If the ETACS-ECU data line voltage is kept at high level for 0.3 second, or the ETACS-ECU has received normal signal from the other ECUs or switches, the ETACS-ECU will stop sending the diagnosis code. While this code is set, the other codes will not be set.
POSSIBLE CAUSES
  • Malfunction of the column switch
  • Malfunction of the front-ECU
  • Malfunction of the sunroof motor assembly
  • Malfunction of the power window main switch <vehicles for Argentina>
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
Step 1. Connector check: A-11X front-ECU connector, C-203 column switch connector, C-228 ETACS-ECU connector, D-09 sunroof motor assembly connector, and E-05 power window main switch connector <vehicles for Argentina>
Q: Is the check result normal?
YES:  Go to Step 2.
NO:  Repair the defective connector.
Step 2. Check the wiring harness from each of A-12X front-ECU connector terminal No.30, C-310 column switch connector terminal No.3, D-09 sunroof motor assembly connector terminal No.10 and E-05 power window main switch connector terminal No.4 <vehicles for Argentina> to C-219 ETACS-ECU connector terminal No.59.
NOTE: Prior to the wiring harness inspection, check joint connector C-02, intermediate connectors C-116, C-118 <vehicles for Argentina>, C-218 and E-12 <vehicles for Argentina>, and repair if necessary.
  • Check the communication lines for open circuit.
Q: Is the check result normal?
YES:  Go to Step 3.
NO:  Repair the wiring harness.
Step 3. Check the wiring harness between C-310 column switch connector terminal No.2 and C-219 ETACS-ECU connector terminal No.68.
  • Check the communication lines for open circuit.
Q: Is the check result normal?
YES:  Go to Step 4.
NO:  Repair the wiring harness.
Step 4. Check whether the diagnosis code is reset.
When A-11X front-ECU connector is disconnected, check that diagnosis code No.21 is not reset. However, diagnosis code No.13 will be set at this time.
Q: Is diagnosis code No.21 set?
YES:  Replace the front-ECU.
NO:  Go to Step 5.
Step 5. Check whether the diagnosis code is reset.
When D-25 sunroof motor assembly connector is disconnected, check that diagnosis code No.21 is not reset.
Q: Is diagnosis code No.21 set?
YES (no DTCs are set):  Replace the sunroof motor assembly.
NO (except for Argentina):  Go to Step 7.
NO (vehicles for Argentina):  Go to Step 6.
Step 6. Check whether the diagnosis code is reset.
When E-05 power window main switch connector is disconnected, check that diagnosis code No.21 is not reset.
Q: Is diagnosis code No.21 set?
YES:  Replace the power window main switch.
NO:  Go to Step 7.
Step 7. Check that the hazard warning lamps illuminate.
When the ignition switch is turned to the LOCK (OFF) position, check if the hazard warning lamps illuminate.
Q: Is the check result normal?
YES:  Refer to diagnosis code No.12 "Column switch fault or improper connection ."
NO:  Refer to Inspection Procedure A-2 "Check the ETACS-ECU battery power supply circuit ."
[54D] SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR <Except for Hong Kong spec.> - - DIAGNOSTIC TROUBLE CODE PROCEDURES - Diagnosis code 21: Short circuit in SWS communication linePRINT PAGE / INDEX / PRIOR / NEXT
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