What causes a P0633 code?

Common causes: New key not programmed; Failed transponder; Failed immobilizer module.

What are the symptoms of a P0633 code?

Typical symptoms: Engine cranks but won't start; Security light.

No — this code can cause damage if you keep driving. Get it diagnosed before continuing. Estimated repair: $100-$500.

OBD-II Code · Powertrain

Immobilizer Key Not Programmed

high severityDo not drive$100-$500

PCM does not recognize the immobilizer key.

Common symptoms

Likely causes

Where to start

Try the cheapest cause first. Start by checking: new key not programmed.
Cost & scope. $100-$500
If the code returns after the fix: escalate to a shop or scanner with live-data and freeze-frame. A code that re-sets means the underlying fault is still there. Don't keep driving with this one active — risk of damage.

Look up another code

More free tools