Code No.B2101 IG SW start POS.circuit low
Code No.B2102 IG SW start POS.circuit high



caution
  • If the diagnosis code No. B2101 or B2102 is set in KOS-ECU, always diagnose the CAN bus lines.
  • Before replacing the ECU, ensure that the communication circuit is normal.











TROUBLE JUDGMENT




JUDGEMENT CRITERIA



B2101
  • Status of ignition switch: ON position
  • Ignition switch position information: OFF
B2102
  • Status of ignition switch: OFF position
  • Ignition switch position information: ON

PROBABLE CAUSES



  • Malfunction of CAN bus line
  • Malfunction of the KOS-ECU
  • Malfunction of the ignition switch
  • Damaged wiring harness and connectors
  • Malfunction of ETACS-ECU

DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III CAN bus diagnostics


Use 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 2.

STEP 2. Connector check: C-317 ETACS-ECU connector, C-104 KOS-ECU connector


Q. Is the check result normal?

Go to Step 3.
Repair the defective connector.

STEP 3. Check the wiring harness between the C-317 ETACS-ECU connector terminal No. 5 and the C-104 KOS-ECU connector terminal No. 39.



  • Check the power supply line for open circuit.

Q. Is the check result normal?

Go to Step 4.
Repair the wiring harness.

STEP 4. M.U.T.-III other system data list


Use M.U.T.-III to check the ETACS service data. (Refer to GROUP 54A - ETACS, Service Data Reference List ).

  • Item 254: IG voltage
OK: Battery voltage

Q. Is the check result normal?

Go to Step 5.
Perform troubleshooting for ETACS (Refer to GROUP 54A - ETACS - Troubleshooting ).

STEP 5. Check whether the diagnosis code is reset.


(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace KOS-ECU and register the ID codes (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Deal with Intermittent Malfunction ).