P1696 Citroen Immobilizer – Key Mismatched

P1696 Citroen Immobilizer – Key Mismatched

Possible causes

– Faulty Smart key ECM

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1696 Citroen Description

Smart key System consists of transponder, which is in the FOB key head, and Smart key ECM. Smart Key System has FOB holder, which includes antenna coil, to communicate with transponder for immobilizer communication.

Smart Key ECM communicates with PDM via serial communication line so that Smart Key ECM sends signal to PDM.

FOB is requested authentication from Smart Key ECM by using the LF antenna with LF communication. And then, FOB sends authentication signal through the SRx with RF communication.

With this procedure, Smart Key ECM sends authentication signal to Engine ECM in order to allow the engine start.

Authentication for immobilizer is classified two different way. one is pre- authentication and the other is general authentication.

Regardless of success or failure, Pre-authentication makes Immoblizer lamp remains OFF. However, General authentication makes Immobilizer lamp is ON for 30 seconds If authentication is successful. However, if authentication is failed, Immobilizer lamp is OFF for 10 seconds.

Citroen Vehicle:2013 Citroen,2012 Citroen,2011 Citroen,2010 Citroen,2009 Citroen,2008 Citroen,2007 Citroen,2006 Citroen,2005 Citroen,2004 Citroen,2003 Citroen,2002 Citroen,2001 Citroen,2000 Citroen,1999 Citroen,1998 Citroen,1997 Citroen,1996 Citroen,