[54B] SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR <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 power window main switch
  • Malfunction of the sunroof assembly
  • Malfunction of the ETACS-ECU
  • Damaged harness wires and connectors
DIAGNOSIS PROCEDURE
Step 1. Connector check: A-12X front-ECU connector, C-310 column switch connector, C-219 ETACS-ECU connector, E-05 power window main switch connector, and D-09 sunroof motor assembly connector
Q: Is the check result normal?
YES:  Go to Step 2.
NO:  Repair the 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, E-05 power window main switch connector terminal No.4 and D-09 sunroof motor assembly connector terminal No.10 to C-219 ETACS-ECU connector terminal No.59.
NOTE: Prior to the wiring harness inspection, check joint connector C-02, intermediate connectors C-30, C-116, C-218 and E-29 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:  Go to Step 5.
NO:  Replace the front-ECU.
Step 5. 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:  Go to Step 6.
NO:  Replace the power window main switch.
Step 6. Check whether the diagnosis code is reset.
When D-09 sunroof motor assembly connector is disconnected, check that diagnosis code No.21 is not reset.
Q: Is diagnosis code No.21 set?
YES:  Go to Step 7.
NO:  Replace the sunroof motor assembly.
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 "Trouble related to the Column switch or improper connection with the ETACS-ECU ."
NO:  Refer to inspection procedure A-2 "Check the battery power supply circuit to the ETACS-ECU ."
[54B] SMART WIRING SYSTEM (SWS) NOT USING SWS MONITOR <Hong Kong spec.> - - DIAGNOSTIC TROUBLE CODE PROCEDURES - Diagnosis code 21: Short circuit in SWS communication linePRINT PAGE / INDEX / PRIOR / NEXT
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