DTC B1A25: Transponder ID unmatched: Diagnosis

WARNING: This page is about a different car, the 2014 Mitsubishi Outlander. However, it is still accessible from the selected car via links, so may be relevant.

STEP 1. All of the registered keyless operation keys should allow the engine switch to be turned from OFF to ACC, ON, START positions.
1. Prepare all of the registered keyless operation keys.
2. Remove the batteries from all of the keyless operation keys (Refer to KEYLESS OPERATION KEY ).
3. Insert one of the keyless operation keys into the key slot.
4. Check whether the engine switch can be turned from LOCK (OFF) to ACC, ON, START positions.
5. Turn the engine switch to LOCK (OFF) position again.
6. Repeat the same procedure for the other keyless operation keys.
7. Install the batteries to all the keyless operation keys.
Q: Is the check result normal?

The engine switch can be turned from LOCK (OFF) to ACC, ON, START positions by operating all of the keyless operation keys.: Check if the DTC is stored. If the DTC is erased, the diagnosis complete. If not, go to Step 3.

The engine switch cannot be turned from LOCK (OFF) to ACC, ON, START positions by operating all of the keyless operation keys.: Check whether DTC B2352 is stored. If DTC B2352 is stored, go to the troubleshooting (Refer to DTC B2352: ANTENNA FAIL ). Repeat Step 1. If DTC B2352 is not stored, go to Step 2.
STEP 2. Register the keyless operation key(s) which cannot activate the engine switch again.
Register the keyless operation key(s) which cannot activate the engine switch again (Refer to ON-VEHICLE SERVICE < KOS-ECU > ).

Q: Is the check result normal?

All of the keyless operation keys can be registered again.: Go to Step 3.

All of the keyless operation keys cannot be registered again.: The keyless operation key(s), which cannot be registered, is defective. Put it aside. Go to Step 3.
STEP 3. Register all of the keyless operation keys again.
1. Register all of the registered keyless operation keys again (Refer to ON-VEHICLE SERVICE < KOS-ECU > ).
  NOTE: Exclude the keyless operation key(s) which you put aside on Step 2.
2. Remove the batteries from all of the keyless operation keys (Refer to KEYLESS OPERATION KEY ).
3. Insert one of the keyless operation keys into the key slot.
4. Check whether the engine switch can be turned from LOCK (OFF) to ACC, ON, START positions.
5. Turn the engine switch to LOCK (OFF) position again.
6. Repeat the same procedure for the other keyless operation keys.
7. Install the batteries to all the keyless operation keys.
Q: Is the check result normal?

The engine switch can be turned from LOCK (OFF) to ACC, ON, START positions by operating all of the keyless operation keys.: Check if the DTC is stored. If the DTC is erased, the diagnosis is complete. If not, go to Step 5.

The engine switch cannot be turned from LOCK (OFF) to ACC, ON, START positions by operating all of the keyless operation keys.: Go to Step 4.
STEP 4. Replace the keyless operation key(s) which cannot activate the engine switch with a new one.
1. Replace the keyless operation key(s) which cannot activate the engine switch with a new one.
2. Register a new keyless operation key (Refer to ON-VEHICLE SERVICE < KOS-ECU > ).
3. Check that all of the registered keyless operation keys allow the engine switch to be turned from OFF to ACC, ON, START positions.
  1. Remove the batteries from all of the keyless operation keys (Refer to KEYLESS OPERATION KEY ).
  2. Insert one of the keyless operation keys into the key slot.
  3. Check whether the engine switch can be turned from LOCK (OFF) to ACC, ON, START positions.
  4. Turn the engine switch to LOCK (OFF) position again.
  5. Repeat the same procedure for the other keyless operation keys.
  6. Install the batteries to all the keyless operation keys.
Q: Is the check result normal?
1. YES: Go to Step 6.
2. NO: Replace KOS-ECU and register the ID codes (Refer to ON-VEHICLE SERVICE < KOS-ECU > ).
STEP 5. Replace the KOS-ECU, and then register all of the keyless operation keys again.
1. Replace KOS-ECU and register the ID codes (Refer to ON-VEHICLE SERVICE < KOS-ECU > ).
2. Register all of the keyless operation keys again (Refer to ON-VEHICLE SERVICE < KOS-ECU > ).
3. Check that all of the registered keyless operation keys allow the engine switch to be turned from OFF to ACC, ON, START positions.
  1. Remove the batteries from all of the keyless operation keys (Refer to KEYLESS OPERATION KEY ).
  2. Insert one of the keyless operation keys into the key slot.
  3. Check whether the engine switch can be turned from LOCK (OFF) to ACC, ON, START positions.
  4. Turn the engine switch to LOCK (OFF) position again.
  5. Repeat the same procedure for the other keyless operation keys.
  6. Install the batteries to all the keyless operation keys.
Q: Is the check result normal?
1. YES: Go to Step 6.
2. NO: Replace KOS-ECU and register the ID codes (Refer to ON-VEHICLE SERVICE < KOS-ECU > ).
STEP 6. Check whether the DTC is stored again.
Check again if the DTC is stored 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 the DTC is stored.
4. Turn the power supply mode of the engine switch to OFF.
Q: Is the DTC stored?
1. YES: Replace KOS-ECU and register the ID codes (Refer to ON-VEHICLE SERVICE < KOS-ECU > ).
2. NO: The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).