Keyless Operation System (KOS)

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.

KOS-ECU Communication Circuit:

DTC SET CONDITION
If the actual ignition switch status is different from the ignition switch status information received from ETACS-ECU via CAN, KOS-ECU sets diagnostic trouble code No.B2101 or B2102.

TECHNICAL DESCRIPTION (COMMENT)
If the difference in the ignition switch level shown below occurs consecutively 10 times with the ignition switch in the ON position or START position, when the CAN message (ignition switch position information) from ETACS-ECU, KOS-ECU determines that there is a problem.

B2101
- Status of ignition switch: OFF position
- Ignition switch position information: ON

B2102
- Status of ignition switch: ON position
- Ignition switch position information: OFF

TROUBLESHOOTING HINTS
- 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

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.







CAUTION: To prevent damage to scan tool (MB991958), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (MB991958).

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the CAN bus line found to be normal?

YES : Go to Step 2.

NO : Repair the CAN bus line.

STEP 2. Check ETACS-ECU connector C-317 and KOS-ECU connector C-05 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is ETACS-ECU connector C-317 and KOS-ECU connector C-05 in good condition?

YES : Go to Step 3.

NO : Repair the defective connector.

STEP 3. Check the wiring harness between KOS-ECU connector C-05 (terminal No.39) and ETACS-ECU connector C-317 (terminal No.5) for open circuit

1. Disconnect KOS-ECU connector C-05 and ETACS-ECU connector C-317, and check the wiring harness.







2. Check the wiring harness between KOS-ECU connector C-05 (terminal No.39) and ETACS-ECU connector C-317 (terminal No.5)

OK: Continuity exists (2 ohms or less)

Q: Is the wiring harness between KOS-ECU connector C-05 (terminal No.39) and ETACS-ECU connector C-317 (terminal No.5) in good condition?

YES : Go to Step 4.

NO : Repair the wiring harness between KOS-ECU connector C-05 (terminal No.39) and ETACS-ECU connector C-317 (terminal No.5).

STEP 4. Using scan tool MB991958, check data list.

Use the ETACS-ECU data list to check the signals related to the ignition voltage.

1. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.







Q: Does scan tool MB991958 display the item "IG voltage" as normal condition?

YES : Go to Step 5.

NO : Diagnose the ETACS-ECU (Refer to ETACS, Diagnosis). Diagnostic Trouble Code Descriptions

STEP 5. Recheck for diagnostic trouble code.

Check again if the DTC is set to the KOS-ECU.
1. Erase the DTC.
2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
3. Check if DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC set?

YES : Replace KOS-ECU and register the ID codes.

NO : The trouble can be an intermittent malfunction.