Honda 2004 Odyssey Service Manual page 1915

Immobilizer System
System Description
The vehicle is equipped with an immobilizer system that will disable the vehicle unless the proper ignition key is used.
This system consists of a transponder located in the ignition key, an immobilizer receiver unit, an indicator light, and
the PCM.
The vehicle has two kinds of keys.
• The black master key for:
– Ignition switch.
– Door locks.
– Tailgate lock.
– Glove box.
• The gray valet key for:
– Ignition switch.
– Door locks.
When the key is inserted in the ignition switch and turned to the (II) position, the immobilizer receiver unit sends
power to the transponder in the ignition key. The transponder then sends a coded signal back through the immobilizer
receiver unit to the PCM.
• The immobilizer system can store up to six key codes.
• If it is necessary to rewrite the PCM, the dealer needs the customer's vehicle, all its master keys and valet keys, and
the HDS. Any key that is not learned during rewriting will no longer start the engine.
• It is possible to add ONE new key without reprogramming all of the keys.
• If the customer has lost his key, and cannot start the engine, contact Honda Customer Relations.
IGNITION KEY
(Has built-in transponder)
22-236
IMMOBILIZER RECEIVER UNIT
KEY CYLINDER
FUEL SUPPLY
PCM
SYSTEM