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B code body Medium severity

B1602 PATS Received Invalid Format Of Key-Code From Ignition Key Transponder

The OBD2 code B1602 indicates that the vehicle's Passive Anti-Theft System (PATS) has received an invalid key code format from the ignition key transponder, suggesting a potential issue with the key or the transponder...

Definition

The OBD2 code B1602 indicates that the vehicle's Passive Anti-Theft System (PATS) has received an invalid key code format from the ignition key transponder, suggesting a potential issue with the key or the transponder system

Common causes

  • Faulty ignition key transponder
  • Damaged or worn key
  • Malfunctioning ignition switch
  • Poor connection or wiring issues in the PATS system
  • Corrupted or faulty PATS module
  • Incorrectly programmed key
  • Interference from electronic devices
  • Low battery voltage in the key fob or vehicle battery

Common misdiagnoses

  • Faulty ignition switch
  • Defective key fob or transponder
  • Weak or dead key fob battery
  • Malfunctioning body control module (BCM)
  • Wiring issues or shorts in the ignition system
  • Incorrectly programmed key or transponder
  • Issues with the vehicle's anti-theft system
  • Faulty or damaged ignition lock cylinder

Troubleshooting steps

  1. 1. Check Key Condition

  2. 2. Inspect the ignition key for any physical damage, such as cracks or wear. A damaged key may not be recognized by the transponder system

  3. 3. Test Spare Key

  4. 4. If you have a spare key, try using it to see if the issue persists. If the spare key works, the original key may be faulty

  5. 5. Inspect Ignition Cylinder

  6. 6. Check the ignition cylinder for any signs of wear or damage. A malfunctioning ignition cylinder can prevent proper communication with the transponder

  7. 7. Check Battery Voltage

  8. 8. Ensure that the vehicle's battery is fully charged. Low voltage can affect the performance of the PATS system

  9. 9. Scan for Additional Codes

  10. 10. Use an OBD-II scanner to check for any additional trouble codes that may provide more context to the issue. Address any other codes that may be present

  11. 11. Inspect Wiring and Connectors

  12. 12. Check the wiring and connectors related to the PATS system for any signs of damage, corrosion, or loose connections

  13. 13. Reprogram Key

  14. 14. If the key is determined to be functional but still not recognized, it may need to be reprogrammed to the vehicle. This typically requires specialized equipment and may need to be done by a dealership or a qualified locksmith

  15. 15. Check for Software Updates

  16. 16. In some cases, the vehicle's software may need to be updated. Check with the manufacturer for any available updates related to the PATS system

  17. 17. Inspect the PATS Module

  18. 18. If all else fails, the issue may lie within the PATS module itself. Testing or replacing the module may be necessary, which usually requires professional assistance

  19. 19. Consult a Professional

  20. 20. If you are unable to resolve the issue after performing these steps, it may be best to consult a professional mechanic or a dealership that specializes in your vehicle make and model. Always remember to take proper safety precautions when working on your vehicle, and if you're unsure about any step, it's best to seek professional help