B1602
DTC B1602 - INVALID KEY CODE FORMAT FROM ENCODED IGNITION KEY TRANSPONDER (PARTIAL KEY READ)Step 1 - 3:
NOTE: Large metallic objects, electronic devices on the key chain that can be used to purchase gasoline or similar items, or a second key on the same key ring as the PATS ignition key may cause vehicle starting problems and record DTCs under certain conditions. If a fault cannot be identified, examine the customer's key ring for such objects or devices. If present, inform the customer that they need to keep these objects from touching the PATS ignition key while starting the engine.
These objects and devices cannot damage the PATS ignition key, but can cause a momentary concern if they are too close to the key during engine start. If a concern occurs, turn ignition OFF and restart the engine with all other objects on the key ring held away from the ignition key. Check to make sure the encoded ignition key used by the customer is a Mazda approved encoded ignition key (Mazda is the only approved encoded ignition key).