Symptom hub
Security Light On and Car Won’t Start? Key, Immobilizer, or Wiring
A security or anti-theft light changes the whole diagnostic order. When the car cranks but will not start, starts and dies, or says the key is not recognized, treat immobilizer and key-programming faults as primary clues instead of fuel-pump guesses. P0513 points more toward a key that is being rejected right now, while P0633 points harder toward a programming or module-matching problem after key or PCM work.
Likely related codes
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U0140 — Lost Communication With Body Control Module P0615 — Starter Relay Circuit P0616 — Starter Relay Circuit Low P0617 — Starter Relay Circuit High P0512 — Starter Request Circuit P2534 — Ignition Switch Run/Start Position Circuit Low P2535 — Ignition Switch Run/Start Position Circuit High P2536 — Ignition Switch Accessory Position Circuit Low P2537 — Ignition Switch Accessory Position Circuit High P0513 — Incorrect Immobilizer Key P0633 — Immobilizer Key Not Programmed - ECM/PCM