KEYLESS-GO IGNITION SWITCH WITH FAULT BACKUP

• US 20100188192A1
• Filed: 01/29/2009
• Published: 07/29/2010
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Lumley, Paul, Sanchez, Luis Fernando, Blossfeld, Mike
• Granted Patent: US 8,542,092 B2
• Time in Patent Office: Days
• US Class Current: 340/5.640
• CPC Class Codes: B60R 25/10 actuating a signalling device

Abstract

A vehicle ignition system includes a fob for transmitting an identification code. The fob includes a low frequency transceiver circuit and low frequency antenna. An ignition module is provided including, a housing, switch contacts and a push button slidably mounted in the housing and arranged so that pushing of said button closes said switch contacts. A LF coil is provided and is axially stationary within the housing and is located inside of the push button. An ignition module circuit provides power to the fob and establishes low frequency communications with the fob via the LF coil. An immobilizer circuit is operatively coupled to the ignition module for permitting or preventing actuation of the ignition system in response to the low frequency communications with the fob and the ignition module.

Claims

1. A vehicle ignition system comprising:

a fob including a low frequency transceiver;

an ignition module including a low frequency transceiver; and

control circuit associated with said ignition module for activating said low frequency transceiver of said ignition module to transmit a low frequency energy signal to said fob to energize said fob,

said fob low frequency transceiver, upon receiving the low frequency energy signal from said low frequency transceiver of said ignition module, transmitting a low frequency response signal,

said control circuit including a verification device to verify that said fob is a fob associated with that vehicle based on the low frequency response signal.

2. A vehicle ignition system comprising:

a fob for transmitting an identification code, said fob including a low frequency transceiver circuit and low frequency antenna;

an ignition module including,

(a) a housing;

(b) switch contacts;

(c) a push button slidably mounted in said housing and arranged so that pushing of said button closes said switch contacts;

(d) a LF coil axially stationary within said housing and located inside of said push button;

(e) an ignition module circuit to power said fob and to establishing low frequency communications with said fob via said LF coil; and

an immobilizer circuit operatively coupled to the ignition module for permitting or preventing actuation of said ignition system in response to the low frequency communications with said fob and said ignition module.

3. A vehicle ignition module comprising:

a fob having radio frequency transmitter and low frequency transceiver, said fob responding to a low frequency interrogation signal by transmitting a radio frequency response signal having a unique fob identification code and transmitting a low frequency response signal when placed in proximity to low frequency signal source;

an ignition module including a radio frequency receiver, a low frequency transmitter, and a low frequency transceiver, said ignition module,

(a) first generating a low frequency interrogation signal from the low frequency transmitter and monitoring for a radio frequency response signal using the radio frequency receiver, and

(b) if no radio frequency response signal is received by the radio frequency receiver, generating a low frequency interrogation signal from said low frequency transceiver and monitoring for a low frequency response signal by the low frequency transceiver,

said ignition module permitting engine start if either a radio frequency response signal is received or a low frequency response signal is received.

4. The vehicle ignition module of claim 3 a radio frequency response signal from said radio frequency receiver, and said low frequency response signal from said low frequency transceiver both include identification codes and wherein said ignition modules includes a circuit to compare the received identification codes against a predetermined code to determine if the fob is a fob associated with that vehicle.