Keyless Operation System (KOS)
DTC B1A35: Transponder Read ErrorCAUTION:
- When DTC B1A35 is set, be sure to diagnose the CAN bus line.
- When replacing the ECU, always check that the communication circuit is normal.
DTC SET CONDITION
If no transponder data can be received, KOS-ECU sets DTC B1A35.
TECHNICAL DESCRIPTION (COMMENT)
KOS-ECU determines that the abnormality is present, if it cannot receive the key ID for the keyless operation key when the ignition switch is turned ON.
TROUBLESHOOTING HINTS
- Insufficient inverse insertion of keyless operation key at the emergency operation
- Malfunction of CAN bus line
- Malfunction of the keyless operation key
- Interference of the key ID
- Malfunction of KOS-ECU
- Ignition switch ON by the emergency key only
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. Sufficiently insert the keyless operation key in the inverted direction at the emergency operation, and recheck the diagnostic trouble code.
With the emergency operation by the sufficient inverse insertion of keyless operation key, recheck if the DTC is set.
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. With the emergency operation by the sufficient inverse insertion of keyless operation key, turn the ignition switch from the LOCK (OFF) position to the ON position.
3. Check if DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 2.
NO : The procedure is complete.
STEP 2. Using scan tool MB991958, diagnose the CAN bus line.
1. Turn the ignition switch to the "ON" position.
2. Diagnose the CAN bus line.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?
YES : Go to Step 3.
NO : Repair the CAN bus line.
STEP 3. Check the emergency key and keyless operation key inserted in the key cylinder for interference.
Check if there are other keys or anything that interferes with the communication (things that generate radio waves such as magnets and an air-cleaning device that has a power plug) near the key inserted in the key cylinder.
Q: Are there other keys or anything that interferes with the communication?
YES : Move away or remove other keys or anything that interferes with the communication, and go to Step 4.
NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set to the KOS-ECU.
1. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
2. Check if DTC is set.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES : Go to Step 5.
NO : The trouble can be an intermittent malfunction.
STEP 5. Replace the keyless operation key and recheck the diagnostic trouble code.
Replace the keyless operation key for which the DTC is set with the other key, and check whether the DTC is reset.
1. Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
2. Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 6.
NO : Go to Step 7.
STEP 6. Register the key ID and recheck the diagnostic trouble code.
Register the key ID and keyless operation key ID of the keyless operation key by which the DTC is set, ID Codes Registration Judgement Table and recheck if the DTC is set.
1. Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
2. Check if the DTC is set.
Q: Is the DTC set?
YES : Go to Step 7.
NO : The procedure is complete.
STEP 7. Replace the keyless operation key and recheck the diagnostic trouble code.
Replace the keyless operation key for which the DTC is set with a new one, register the key ID and keyless operation key ID, and check whether the DTC is reset.
1. Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
2. Check if the DTC is set.
Q: Is the DTC set?
YES : Replace KOS-ECU and register the ID codes.
NO : The procedure is complete.