B1645 Code failures by brands


Description of DTC code B1645

The Remote Control System consists of a keyless transmitter. By performing a one-button operation all the doors can be locked or unlocked. This process can be done from the vehicle remotely. The keyless transmitter sends a corresponding switching signal to the Keyless Access Control Unit. This process occurs If the remote lock or unlock button is activated. By the time authentication is received at the control unit, the MICU via B-CAN receives the door lock signals.


The low-frequency (LF) antenna of the front interior, the middle interior, and the rear interior provide signals to the car interior remote control. The outside driver's door handle, outside front passenger's door handle, and the rear bumper LF antennas, send signals to the remote control outside the vehicle.

When the B1645 OBDII diagnostic code is stored, it means that a short was detected in the driver's door LF antenna circuit.

Symptoms of fault code B1645

  • Check Engine lamp illuminated.
  • Remote Control System operations cannot be performed.

Causes of OBD2 B1645

OBD2 fault code B1645 is set by the following:

  • Driver's door low frequency (LF) antenna circuit wiring may be deficient.
  • Electrical connections of the driver's door LF antenna circuit may have damage causing the short.
  • Driver's door LF antenna may be defective.
  • The Keyless Access Control Unit could be in poor condition.

Possible solutions of the DTC code B1645

To troubleshoot the DTC B1645 OBDII code, try this:

  • Consult the TSB (Technical Service Bulletins).
  • Check all the wiring in the low frequency (LF) antenna circuit in the driver's door. Look for shortages caused by corrosion or wear and tear and if such damage is found, make appropriate repairs.
  • Make electrical tests on the driver's door LF antenna circuit. Compare the voltages of this circuit to rule out poor connections causing the short. Fix if necessary.
  • Check the condition of the driver's door low frequency (LF) antenna. For this diagnosis, take into account the recommendations given by the manufacturer. Make adjustments as required.

Codes related to B1645

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