P1621 – Mazda DTC

Mazda DTC P1621 – lmmobilizer System Fault

DTC P1621 meaning on Mazda

DTC P1621 on a Mazda refers to an Immobilizer System Fault. This fault code indicates a problem with the vehicle’s immobilizer system, which is designed to prevent unauthorized access and theft.

Mazda DTC P1621 symptoms

Symptoms of DTC P1621 on a Mazda may include:

  • Engine not starting or cranking
  • Immobilizer warning light illuminated on the dashboard
  • Loss of communication with the key fob

Mazda DTC P1621 causes

Common causes of DTC P1621 on a Mazda include:

  • Issues with the immobilizer system antenna
  • Problems with the key fob or key transponder
  • Wiring or connection issues in the immobilizer system circuit

Mazda DTC P1621 seriousness

The seriousness of DTC P1621 on a Mazda lies in the potential security risk of unauthorized access to the vehicle. It is important to address this fault code promptly to ensure the proper functioning of the immobilizer system.

How to diagnose DTC P1621 on Mazda

To diagnose DTC P1621 on a Mazda, a mechanic may perform the following steps:

  1. Scan the vehicle’s onboard diagnostic system for fault codes
  2. Inspect the immobilizer system components for any visible damage or issues
  3. Test the key fob and transponder for proper functionality
  4. Check the wiring and connections in the immobilizer system circuit

How to fix DTC P1621 on Mazda

To fix DTC P1621 on a Mazda, the following steps may be taken:

  1. Repair or replace any damaged components in the immobilizer system
  2. Reprogram the key fob or key transponder if necessary
  3. Ensure proper wiring connections in the immobilizer system circuit
  4. Clear the fault code and reset the vehicle’s immobilizer system

How to erase DTC P1621 on Mazda

To erase DTC P1621 on a Mazda, the fault code can be cleared using a diagnostic scanner or tool that is capable of resetting the vehicle’s onboard computer. Once the fault code is cleared, the immobilizer system should be retested to ensure proper functionality.

Recommended tools for Mazda diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.