WOMS
P code powertrain Medium severity

P1622 Immobilizer ID Does Not Match

The OBD2 code P1622 indicates that the immobilizer system has detected a mismatch between the vehicle's key or transponder ID and the stored ID in the engine control unit (ECU), preventing the engine from starting

Definition

The OBD2 code P1622 indicates that the immobilizer system has detected a mismatch between the vehicle's key or transponder ID and the stored ID in the engine control unit (ECU), preventing the engine from starting

Common causes

  • Incorrect key or key fob
  • Faulty ignition switch
  • Malfunctioning immobilizer system
  • Damaged or corroded wiring/connectors
  • Faulty engine control module (ECM)
  • Incorrectly programmed key
  • Issues with the vehicle's security system
  • Low battery voltage in the key fob or vehicle
  • Faulty transponder chip in the key

Common misdiagnoses

  • Faulty ignition switch
  • Bad key or key fob
  • Defective immobilizer module
  • Wiring issues or shorts
  • Faulty engine control unit (ECU)
  • Incorrectly programmed key
  • Malfunctioning transponder system
  • Battery issues or low voltage

Troubleshooting steps

  1. 1. Check the Key

  2. 2. Ensure that you are using the correct key for the vehicle. If you have a spare key, try using it to see if the issue persists

  3. 3. If the key has a transponder, check for any physical damage or wear

  4. 4. Inspect the Ignition System

  5. 5. Check the ignition switch and wiring for any signs of damage or corrosion

  6. 6. Ensure that the ignition system is functioning properly

  7. 7. Examine the Immobilizer System

  8. 8. Verify that the immobilizer system is functioning correctly. This may involve checking the immobilizer control unit and its connections

  9. 9. Look for any loose or damaged wiring in the immobilizer circuit

  10. 10. Scan for Additional Codes

  11. 11. Use an OBD-II scanner to check for any other related trouble codes that may provide more context to the issue

  12. 12. Address any other codes that may be present, as they could be contributing to the problem

  13. 13. Check the Vehicle's Battery

  14. 14. Ensure that the vehicle's battery is fully charged and in good condition. A weak battery can sometimes cause issues with the immobilizer system

  15. 15. Reprogram the Key/Transponder

  16. 16. If you have recently replaced the key or the immobilizer system, you may need to reprogram the key to match the vehicle's immobilizer

  17. 17. Follow the manufacturer's instructions for key programming, which may require specialized equipment

  18. 18. Inspect the ECU

  19. 19. Check the Engine Control Unit (ECU) for any signs of damage or malfunction. In some cases, the ECU may need to be reprogrammed or replaced

  20. 20. Consult the Vehicle Manual

  21. 21. Refer to the vehicle's service manual for specific troubleshooting steps related to the immobilizer system and P1622 code

  22. 22. Seek Professional Help

  23. 23. If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or dealership. They will have the tools and expertise to diagnose and repair complex issues related to the immobilizer system. By following these steps, you can systematically identify and resolve the issue associated with the P1622 code