Passive Anti-Theft System (PATS) Function

WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, and 2011 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

The PATS function is controlled by the IPC. PATS uses the IPC to carry out all of the PATS functions such as receiving the ID code from the PATS key, issuing a signal to the TCM to control the starting and fuel injectors enable, and initiating the key interrogation sequence when the ignition key is turned to the ON or START position. Because of the interaction between the IPC and the TCM, there are parameters that must be set if the IPC and/or TCM are replaced. Refer to PASSIVE ANTI-THEFT SYSTEM (PATS) PARAMETER RESET in this service information. If the IPC must be replaced for any reason (PATS or IPC concerns), the PATS keys also must be programmed into the new IPC. Refer to INTEGRATED KEYHEAD TRANSMITTER (IKT) KEY PROGRAMMING USING DIAGNOSTIC EQUIPMENT in this service information. All elements of PATS must be functional before the vehicle starts. If any of the components are not working correctly, the vehicle does not start.

PATS is active only for a few seconds when the vehicle is starting. It is not a PATS concern if the vehicle stalls after it has been running for a minimum of 3 seconds. PATS cannot disable a running vehicle.

PATS can cause a vehicle no start due to either the TCM does not start the engine or the TCM does not move the vehicle electrically or both. Always check for PATS DTCs from the IPC and DTCs from the TCM when a no-crank or no-start condition exists.

If the anti-theft indicator does not prove out (it may be either flashing or glowing steadily) and one (or both) of the previous conditions (TCM does not start the engine or move the vehicle electrically) are present, it may be due to a PATS concern. If the anti-theft indicator proves out, it may not be a PATS concern. If the anti-theft indicator does not illuminate at all, it may be an IPC concern. Refer to the SYMPTOM CHART in this service information.

PATS is not compatible with non-Ford remote start systems, which allow the vehicle to be started from the exterior of the vehicle. These systems may reduce the security of the vehicle, and also may be the cause of no-start concerns. Remote start systems must be removed from the vehicle before any PATS-related no-start concerns are investigated.