Inspection procedure 14: The seat belt warning lamp does not illuminate or flash.


caution Whenever the ECU is replaced, ensure that the input and output signal circuits are normal.


COMMENTS ON TROUBLE SYMPTOM




  • Ignition switch (IG1)
  • Driver’s seat belt switch
  • Passenger’s seat belt switch
  • Vehicle speed signal

PROBABLE CAUSES



  • Malfunction of the seat belt switch (RH)
  • Malfunction of the seat belt switch (LH)
  • 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 54C - Troubleshooting ). On completion, go to Step 5.

STEP 2. Check the diagnosis code of the engine-ECU.
Check if the diagnosis code is set in either of the engine-ECU.

Q. Is the diagnosis code set?
Diagnose the engine-ECU (Refer to GROUP 13A - Troubleshooting . On completion, go to Step 4.
Go to Step 3.

STEP 3. M.U.T.-III data list
Check the input signals below, which are related to the seat belt warning lamp function.

  • Turn the ignition switch to the "ON" position.
  • Remove the each inserted seatbelt.
Item No.
 Item name
 Normal condition
30
 Ignition switch(IG1)
 ON
50
 Driver’s seatbelt(Buckle SW)
 Being turned ON from OFF
51
 Passenger seatbelt(Buckle SW)
OK: Normal conditions are displayed for all the items.

Q. Is the check result normal?
YES <All the signals are received normally.> : Go to Step 4.
NO <The seat belt switch signal is not received.> : Refer to inspection procedure C-6 "The seat belt switch signal is not received <L.H. drive vehicles> or <R.H. drive vehicles>."
NO <The ignition switch (IG1) signal is not received.> : Refer to inspection procedure C-3 "The ignition switch (IG1) signal is not received ."

STEP 4. Check the combination meter

Q. Does the combination meter work?
Go to Step 5.
Refer to symptom procedure 1 "Power supply circuit system check ."

STEP 5. Connector check: C-113 combination meter connector and C-219 ETACS-ECU connector




Q. Is the check result normal?

Go to Step 6.

Repair the defective connector.

STEP 6. Check the wiring harness from C-113 combination meter connector terminal No.9 to C-219 ETACS-ECU connector terminal No.73.





  • Check the output lines for open circuit.

Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness.

STEP 7. Retest the system.
The door-ajar warning lamp function should work normally.

Q. 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 ).
Replace the ETACS-ECU and register the ID codes (Refer to ).