Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Immobilizer Systems: Operation
Immobilizer control unit receives battery voltage through fuse No. 6 at all times. When ignition switch is turned to ON position using proper key with a transponder, PGM-FI main relay coils are energized, closing contacts. With gear selector in Park or Neutral, immobilizer control unit receives an ignition on signal through fuse No. 6 and sends power to ignition key transponder through immobilizer receiver. A coded signal is sent back to immobilizer control unit through the immobilizer receiver. If signal is recognized by control unit, a fuel enable signal is sent to PCM and starter cut relay. Immobilizer indicator light will illuminate for 2 seconds indicating a correct key has been inserted. When ignition switch is turned off, immobilizer indicator light will flash for 5 seconds. If an unrecognized key (or other device) is used to turn ignition switch, engine starting circuit will be disabled. If immobilizer system does not recognize coded key, immobilizer indicator light will illuminate for 2 seconds and then flash continuously.
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Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.