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 JUDGEMENT


If the actual engine switch status is different from the engine switch status information received from ETACS-ECU via CAN, KOS-ECU sets the diagnosis code No. B2101 or B2102.

JUDGEMENT CRITERIA


If the engine switch status is infeasible consecutively ten times the KOS-ECU will judge that the system is defective.
B2101
B2102

PROBABLE CAUSES



DIAGNOSTIC 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. M.U.T.-III other system diagnosis code


Check if any diagnosis code is set to the OSS-ECU.

Q. Is the diagnosis code set?

Perform troubleshooting for the OSS-ECU (Refer to Troubleshooting ). On completion, go to Step 3.

Go to Step 3

STEP 3. M.U.T.-III other system data list


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

OK: System voltage

Q. Is the check result normal?

Go to Step 4

Perform troubleshooting for ETACS-ECU (Refer to GROUP 54A - ETACS-ECU - Troubleshooting ).

STEP 4. Check whether the diagnosis code is reset.


(1)Erase the diagnosis code.
(2)Turn the power supply mode of the engine switch from OFF to ON.
(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 Cope with Intermittent Malfunction ).