Some 2006 Ford Escape and Mariner vehicles built between 10-3-2005 and 11-2-2005 equipped with fender-mounted side turn signal lamps may experience fast-flashing (which normally indicates a burned out bulb) of either the left, right or both turn signals even though a turn signal lamp is not burned out.
In some cases, this fast-flashing is immediately noticeable when the turn signal is activated. In other cases, the bulb will flash normally for quite some time before flashing at a faster rate.
The cause of the issue is an improperly set current threshold within the smart junction box (SJB) associated with the addition of side markers. The threshold is set too close to the normal operating range which in some cases means that the SJB senses less current than expected, thereby fast flashing the turn signals.
Use the following service procedure to alter the programmable settings for the SJB using the worldwide diagnostic system (WDS) release B42.0 or higher to change the “turn signal side markers” customer preference from “equipped” to “not equipped.” This will not affect the proper operation of the turn signal side markers but will force the SJB to use a different threshold value that does not exhibit the fast flash issue.