Code No.B120B Security alarm sensor error
caution |
- Before replacing the ECU or sensor, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
- When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in Immobilizer System - How to Register Key ID
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DIAGNOSTIC FUNCTION
The security alarm sensor communicates with the ETACS-ECU via the LIN bus line. If the diagnosis code No. B120B is stored, the security alarm sensor itself may be defective.
note |
- Diagnosis code No.B120B may be stored when the security alarm sensor cover is improperly installed or is removed. Check if the security alarm sensor cover is properly installed.
- Diagnosis code No.B120B is stored when the ultrasonic wave transmission/reception part of the security alarm sensor is covered. Check if the ultrasonic wave transmission/reception part of the security alarm sensor was covered.
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PROBABLE CAUSES
Malfunction of the security alarm sensor
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STEP 1. M.U.T.-III diagnosis code.
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Check if diagnosis code is stored in the ETACS-ECU.
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Q.
Is the diagnosis code stored?
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Diagnose the ETACS-ECU. Refer to GROUP 54A, Diagnosis .
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Go to Step 2.
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STEP 2. Security alarm sensor operation check
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Ultrasonic wave sensor check
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- With the windows of the vehicle opened, set the security alarm to the "Ready to be triggered" condition.
- Put the arm from the outside to the inside of the vehicle.
- Check that the security alarm siren sounds.
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- Set the security alarm to the "Ready to be triggered" condition.
- Raise the front wheels or rear wheels.
- Check that the security alarm siren sounds.
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Q.
Is the check result normal?
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
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Go to Step 3.
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STEP 3. M.U.T.-III diagnosis code.
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Check if diagnosis code No. B120A is stored to the ETACS-ECU.
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Q.
Is diagnosis code No. B120A stored?
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Perform the troubleshooting of diagnosis code No.B120A. (Refer to .)
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NO <The ultrasonic wave sensor is defective, or the ultrasonic wave sensor and the inclination sensor are defective> : Go to Step 4
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NO <Only the inclination sensor is defective> : Go to Step 5.
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STEP 4. Check the customise function.
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Check if the ultrasonic wave sensor of the security alarm senor operates when the sensitivity of the security alarm senor is set to "Level 1".
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Q.
Is the check result normal?
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
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Go to Step 5
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STEP 5. Replace the security alarm sensor temporarily, and check whether the diagnosis code is stored.
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Check again if the diagnosis code is stored in the ETACS-ECU.
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(1)Erase the diagnosis code.
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(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
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(3)Check if diagnosis code is stored.
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Q.
Is the diagnosis code stored?
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Replace the ETACS-ECU.
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Replace the security alarm sensor.
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