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DTC B2101: IG SW start POS.circuit low
DTC B2102: IG SW start POS.circuit high
 
 
caution
  • If DTC 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.
 
 
 
 
DTC SET CONDITION
If the actual the engine switch status is different from the power supply mode of the engine switch status information received from ETACS-ECU via CAN, KOS-ECU stores DTC B2101 or B2102.
 
 
TECHNICAL DESCRIPTION (COMMENT)
If the difference in the power supply mode of the engine switch level shown below occurs consecutively 10 times with the power supply mode of the engine switch being the ON position or START position, when the CAN message (power supply mode of engine switch position information) from ETACS-ECU, KOS-ECU determines that there is a problem.
B2101
  • Engine switch power supply mode: OFF
  • Engine switch information from ETACS-ECU: ON
B2102
  • Engine switch power supply mode: ON
  • Engine switch information from ETACS-ECU: OFF
 
 
TROUBLESHOOTING HINTS
  • Malfunction of CAN bus line
  • Malfunction of the KOS-ECU
  • Malfunction of the OSS-ECU
  • Damaged wiring harness and connectors
  • Malfunction of ETACS-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the OFF position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect scan tool (M.U.T.-III) ."
(2) Turn the power supply mode of the engine switch to ON.
(3) Diagnose the CAN bus line.
(4) Turn the power supply mode of the engine switch to OFF.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Using scan tool (M.U.T.-III), read the other system diagnostic trouble code.
Check again if the DTC is set in the OSS-ECU.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the OFF position before connecting or disconnecting scan tool (M.U.T-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect scan tool (M.U.T.-III) ."
(2) Erase the DTC.
(3) Turn the power supply mode of the engine switch to ON.
(4) Check if DTC is set.
(5) Turn the power supply mode of the engine switch to OFF.
Is the DTC set?
Perform troubleshooting for the OSS-ECU (Refer to troubleshooting ). On completion, go to Step 3.
Go to Step 3.
 
STEP 3.Using scan tool (M.U.T.-III), check data list.
Use scan tool (M.U.T.-III) to check the ETACS-ECU service data. (Refer to GROUP 54A - ETACS-ECU, Service Data Reference List ).
  • Item 254: IG voltage
OK: The voltage should measure approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 4.
Perform troubleshooting for ETACS-ECU (Refer to GROUP 54A - ETACS-ECU - Troubleshooting ).
 
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set in the KOS-ECU.
(1) Erase the DTC.
(2) Turn the power supply mode of the engine switch from OFF to ON.
(3) Check if DTC is set.
(4) Turn the power supply mode of the engine switch to OFF.
Is the DTC set?
Replace KOS-ECU and register the ID codes (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).