Antitheft and Alarm Systems: Description and Operation
The passive anti-theft system (PATS) uses radio frequency identification technology
to deter a driveaway theft. Passive means that it does not require any activity from
The PATS uses a specially encoded ignition key. Each encoded ignition key contains a
permanently installed electronic device called a transponder. Each transponder
contains a unique electronic identification code, with over 72 million billion
Each encoded ignition key must be programmed into the vehicle powertrain control
module (PCM) before it can be used to start the engine. There are special diagnostic
procedures that must be carried out if new encoded ignition keys are to be
The encoded key is larger than a traditional ignition key. The key does not require
batteries and should last the life of the vehicle.
The transceiver module communicates with the encoded ignition key. This module is
located behind the steering column shroud and contains an antenna connected to a
small electronic module. During each vehicle start sequence, the transceiver module
reads the encoded ignition key identification code and sends the data to the PCM.
The control functions are contained in the PCM. This module carries out all of the
PATS functions such as receiving the identification code from the encoded ignition
key and controlling engine enable. The PCM initiates the key interrogation sequence
when the vehicle ignition switch is turned to ON or START.
The PATS function uses the PCM to enable or disable the engine. All elements of PATS
must be functional before the engine is allowed to start. If any of the components
are not working correctly, the vehicle will not start.
PATS uses a visual theft indicator located on top of the instrument panel. This
indicator will prove out for three seconds when the ignition switch is turned to ON
or START under normal operation. If there is a PATS problem, this indicator will
either flash rapidly or glow steadily (for more than three seconds) when the ignition
switch is turned to ON or START. PATS also "flashes" the theft indicator every two
seconds at ignition OFF to act as a visual theft deterrent.
The PATS is not compatible with aftermarket remote start systems, which allow the
vehicle to be started from outside the vehicle. These systems may reduce the vehicle
security level, and also may cause no-start issues. Remote start systems must be
removed before investigation of PATS-related no-start issues.
The PATs key is used on the following Ford family trucks and suvs:
FORD: 1996-2001 MUSTANG, TAURUS
1998-2001 CROWN VICTORIA
1999 F-250 LD
1999-2001 F-150, RANGER, WINDSTAR
LINCOLN: 1997-1998 MARK VIII
1998-2001 CONTINENTAL, TOWN CAR
MERCURY: 1996-2001 SABLE
1998-2001 GRAND MARQUIS
Additionally, PATs can be found on the follow Ford family cars and mini-vans:
1997-up Crown Victoria
1996-up Mustang and Taurus
1998-up 2000-up Lincoln LS
1998-up Lincoln Mark VIII, Lincoln Continental and Lincoln Town Car
1997-up Mercury Grand Marquis
1998-up Mercury Mystique
1996-up Mercury Sable
Following are the instructions for programming a blank key (you must have at least one working key for this procedure).
1. Make sure you have both keys.
2. Turn on car but don't start. Watch "theft" indicator untils it goes out.
3. Turn off and repeat procedure with second key.
4. After "theft light goes out, insert new key and turn on.
5. Wait until the theft indicator goes off and then turn off switch.
6. Wait thirty seconds. New key is now programmed into security module. Repeat for any other keys.
1. Erase any old codes by entering the factory code.(buttons will light up)
2. Press 1/2 button within 5 seconds.
3. Press 7/8 and 9/0 buttons at the same time within 5 seconds.
To set new code:
1. Enter factory code (numbers will light up)
2. Press 1/2 button within 5 seconds.
3. Enter personal 5 digit code(decide beforehand) within 5 seconds of each previous one.
To unlock all the doors,press the 3/4 button within 5 seconds of the driver door unlocking.
To lock all doors and set alarm system,press 7/8 and 9/0 at the same time.
To disarm or reset a triggered alarm,just enter personal or factory code.
Do not set a code with five of the same consecutive numbers. It's too easy for thieves to figure out.
Deactivating and Activating Autolock
To deactivate the "autolock":
With all doors and tailgate closed but NOT locked,and ignition OFF.
1. Enter 5 digit code
2. While holding 7/8 button in, press and release the 3/4 button.
3. Release 7/8 button
The horn will chirp once if the "autolock" was deactivated
or two times if "autolock" was activated.
To reactivate the system,repeat steps 1 thru 3
Alternate Method To Deactivate And Activate Autolock
Do steps  through  (below) within 30 seconds or you'll have to do it over. If you have to do it over, wait 30 seconds between attempts.
Close all doors securely.
1.Turn the ignition key to ON.
2.Press the power door UNLOCK control THREE times.
3.Turn the ignition key from ON to OFF.
4.Press the power door UNLOCK control THREE times.
5.Turn the ignition key back to ON .The doors should lock and unlock.
6.Press the power door UNLOCK control. The horn should chirp ONCE to confirm successful switching of the autolock system
The engine does not start and LED remains off.
1. Check PATS system fuses
2. If alarm is fitted check if LED functions for alarm: if not check cigar lighter fuse (also used for LED)
3. If not go to main dealer
Engine does not start: LED flashes rapidly Leave ignition on until the LED starts to flash a 2 digit code: (sequence- pause-sequence)
Check the following codes:
1:3 Key code not received. Is key screened by other keys or objects? Try different key: if okay then first key is faulty. If not go to main dealer
1:4 Partial code only received. Try again. If not okay use different key. If not go to main dealer
1:5 Key not programmed into PATS. Program key as above using master
1:6 Faulty link between PATS module and EECV Go to dealer .
For more information and troubleshooting tips:
so I can get an 97 and mount to my truck without any fuel line/pressure issues and may possibly bypass the whole pats system?
I have been having issues with my pats as well. Have poured money into new jgnition and keys, locksmith, having it reprogrammed, and even have tried to shut it off. It still is causing me problems. Ive been following this thread and am considering trying the pcm swap from a older donor to my 2000 Ford Ranger Xlt 3.0L 4x4, w/ 5 spd manual. My question is would a '97 work to switch out, or if not, which one would? I have a few donors that are pre-'98 already at my disposal. I just want to make sure which one would be a good fit, s o i can eliminate pats altogether and have a running truck again.
Sounds like a winner!
It sounds like I won't want the fuel system on a 99 unless I convert it over. What years explorer/mountaineer would I want to look at using? 96,97? to 98?