Understanding The Ford PATS (Passive Anti-Theft System)

How The Ford PATS (Passive Anti-Theft System) System Works

Ford’s PATS Passive Antitheft System uses a key with a transponder in the head of the key. Each transponder is coded with a unique identifying code made from a possible 18 billion combinations. It’s a passive system because it doesn’t require any input from the driver. Ford has also referred to their PATS system as SecuriLock.

The second portion of the system is a PATS transceiver module. The PATS module generates an “exciter” field that powers the chip in the key, which then transmits encoded data back to the transceiver. The key contains a spool of wire that converts the “field” to power to run the chip, so the key never needs battery replacement. The transceiver then communicates with the PATS module.

Where Is The PATS module?

Over the years, Ford has located the PATS module in different places;

In some vehicles, it’s built into the instrument cluster
On some models it’s a separate module.
On some late model vehicles, the PATS module is located behind the steering column shroud and contains an antenna connected to a small electronics module.
In the

As you turn the key to the RUN or START position, the PATS control module initiates the key interrogation routine. The PATS transceiver is mounted on the ignition lock cylinder housing and is connected to the PATS control module. The transceiver energizes the transponder key electronics through the key’s circular antenna. The PATS transceiver receives data from the control module through the transmit Tx signal. The transceiver sends the key code to the control module through the receive Rx signal.

The key code data is stored in the PATS control module. The PATS control module compares the received key code and validates or rejects the key code. If the key code is correct, the PATS control module sends a signal to the PCM to enable the fuel pump and injectors.

During this period, the PATS security warning light is illuminated. If the key code does not prove out or there is a fault with the system, the PATS warning light will either stay light or flash.

These faults will disable the vehicle from starting

Incorrectly encoded ignition key
Damaged encoded ignition key
Unprogrammed key
Non-encoded key (key has no electronics)
Damaged wiring
Damaged transceiver
Damaged PCM

PATS Modules

PATS Variations

Like any electronic system, Ford has gone through several variations on the PATS system. There are five variations of PATS that are used on Ford vehicles. Systems are identified as types A, B, C, D, E, F and G.

PATS System A (1996-1998)

The PATS control is a stand-alone module. When you turn the key to RUN/START, the theft warning light turns on for 2-seconds. Only 1 key needs to be programmed for the system to work. Up to 16 keys can be programmed.

The transceiver sends the key code signal via a hardwired connection to the control module.

At each start sequence, the PCM powers the fuel pump and injectors until the engine runs for 1 second. Within that 1 second period, the PATS Control Module must determine if the key code is valid. If it is, the control module sends a validation signal to the PCM via the Vehicle Communication Network (SCP). The PCM then allow the fuel pump and injectors.

Some vehicles also include a starter relay. If the key code is valid, the PATS control module also grounds the control coil in the starter relay, which moves the contacts and sends power to the starter motor solenoid.

PATS System B (1998-2002)

Same as System A but:

Must have two programmed keys in the control module to allow vehicle starting. Only accepts 8 programmed keys.

PATS System C (1999-2013?)

Same as System B but:

The PATS control module is NOT a standalone module. It is built into the instrument cluster.

PATS System D (1997-1998)

Same as System A but:

The PATS control module is a standalone module located behind the dash on the left side.

PATS System E (2000-2007)

Same as System A but:

The PATS control module is built into the PCM.

The PATS control module in the PCM provides ground to the starter relay and enables the fuel pump and injectors.

PATS System F (2006-2010)

No information at this time.

PATS System G (2007-2010)

I haven’t been able to find anything on the System G except that it uses an Instrument Cluster Module (ICM). The 2007-2010 Ford Ranger, some 2008-2010 Ford F-350’s and some 2008-2010 Ford E-Series use this system.

PATS Activation Signs

PATS Symptoms (The PATS system isn’t working properly if):

You see a rapidly flashing theft indicator with the ignition on
No crank
Start and stall within 1 second
Cranks but won’t start

These are NOT symptoms of a PATS problem

If the vehicle runs for more than 1 second, then stalls, it is not a PATS issue. PATS cannot cause a running vehicle to stall.
Alarm goes off – PATS is completely independent from the perimeter alarm system.
Remote Keyless Entry – PATS is completely independent from the RKE system.
No-crank on a PTS vehicle without starter disable. Check the vehicle list for the presence of starter interrupt.
WARNING: Items such as foil stickers, brass key tags, other PATS keys, other transponders used to purchase gasoline or other metallic objects can cause interference with the PATS key.
Erasing and reprogramming ignition keys does not cure any known intermittent PATS no-start issues. Do not reprogram keys if a fault cannot be identified. Reprogramming the PCM does not have any impact on PATS operation.

Repairing a PATS system

Every day in every auto forum I see people asking how to bypass a Ford PATS system. I just shake my head because fixing a PATS system is NOT difficult and you’ll probably spend more on a bypass kit than it’ll cost to just fix it properly. There are only two parts to the system as shown above: transceiver and control module. A new transceiver costs about $50. If your control module is bad, you can buy a new one from Ford for about $175 or buy a rebuild unit for about $40. Yes, you’ll have to pay a shop to program but you’ve got a full fix for maybe $250 all in and you don’t have to jury rig it.

Start by reading the PATS trouble codes. Most of the PATS trouble codes are body “B” or data “U” type codes. You must have a code reader that can read these codes. Repairing a PATS system is NOT hard.

PATS Codes:

B1213 Less than 2 (or 3 if equipped w/Valet key) keys programmed to the system.

B1232/B2103 Transceiver internal antenna damaged. Replace transceiver.

B1342 ECU is defective (EEPROM in PCM is not working — replace PCM). PATS related when stored in PCM only.

B1600 Non-PATS Key or damaged key.

B1601 Unprogrammed encoded ignition key detected (leave ignition on for 20 seconds before trying a programmed key, in Anti-Scan Mode).

B1602 Partial detection of encoded ignition key.

B1681 Transceiver signal not detected.

B2141 Non-Volatile Memory (NVM) configuration failure — No PCM ID stored in PATS.

B2139/U2510 PCM ID does not match between the PCM and PATS control (PATS/ICM/VIC/HEC/SCIL).

B2431 Key program failure (defective key or transceiver).

U1147/U1262 Communications issue, SCP (J1850), between PCM and PATS control (PATS/ICM/VIC/HEC/SCIL).

U1900/U0100 Communications issue, CAN (J2284), between PCM and PATS control (ICM).

U2511/B2009/P1260 PCM disabled the vehicle because of a PATS concern. Retrieve DTCs from applicable PATS control function (PATS/ICM/VIC/HEC/SCIL).

PATS And The Ford Ranger

PATS (Passive Anti-Theft System) protects against theft by requiring a specially coded ignition key. The vehicle starts and operates only with the key that matches the sensor in the vehicle, thwarting attempts to hot-wire the ignition. An indicator lamp shows the system is working.

How it works: A miniature transponder with integrated circuit and antenna is embedded in the ignition key. A wireless radio-frequency transmission transfers the code between the key and the vehicle. If the codes match, the module sends a signal through the wiring system to the engine electronic control, allowing the engine to start. There are 72 million-billion possible codes, so every Ford sold worldwide for the next 10 billion years could have a unique code. New keys for replacements or spares can be encoded by dealerships.

Type B (1999-2000 Ranger & 1998-2001 Explorer): Under the type B system, the key sends a signal to the PATS transceiver, the transceiver then sends a signal to the PATS transponder (PATS module), and this then sends a signal to the PCM that tells it that its ok to run. For a type “B” system, if the PCM does not receive the “ok to run” signal from the PATS module, then it will still allow the motor to crank, but it will not send pulses to the injectors cutting all fuel.

Type E (2001-2006 Ranger): The type E PATS eliminates the PATS module (transponder) by integrating it into the PCM. Under a type E system, the coded keys send a signal to the PATS transceiver, the transceiver takes the signal and sends it to the PCM where it checks to make sure that the key code is correct and then allows the motor to run. If the PCM fails to detect the properly coded key it will do two things. First, it will not allow the injectors to provide fuel to the motor. Second, if it doesn’t receive the proper signal, it will not ground the starter solenoid and allow the starter to start the motor.

Type G (2007-2010 Ranger): I haven’t been able to find anything on the System G except that it uses an Instrument Cluster Module (ICM). The 2007-2010 Ford Ranger, some 2008-2010 Ford F-350’s and some 2008-2010 Ford E-Series use this system.

Ranger & Explorer PATS Compatibility

The 1999-2001 Explorer PATS is 100% compatible with a 1999-2000 V6 Ranger. If the Explorer PATS module and keys are also transplanted to the Ranger, they should work immediately with the Explorer PCM. If the original Ranger PATS module and keys are reused with the Explorer PCM, a dealer would have to “introduce” the new parts to each other before the engine could start.

If you wanted to install an Explorer 5.0L in to a 1998 Ranger you would have to either incorporate the PATS from the Explorer or use a 1996-1997 Explorer 5.0L and adjust for the fuel rail differences noted above under Fuel System.

The 1996-1997 Explorer 5.0L does not have PATS. The 1998-2004 4-cylinder and 1998 and older Rangers do not have PATS.

PATS Parts needed for swapping an Explorer 5.0L PATS type B in to a Ranger PATS type E:

1. Grab the module behind the passenger air bag
2. Grab the transceiver around the ignition lock
3. Get all the wiring that you can reach between the two

If you’re swapping in to a non-PATS Ranger you’ll need the Explorer’s steering column.

Explorer PATS Module

Vehicles With PATS	Vehicles Without Pats
1999-2000 6-cylinder Ranger —— Type B 1998-2001 Explorer/Mountaineer –Type B 2002-2005 Explorer ——————- Type E 2001-2004 4 & 6-cylinder Ranger –Type E 2006 6-cylinder Ranger ————– Type E 2007-2010 4 & 6-cylinder Ranger – Type G	1996-1997 (1997 & Older) Explorer/Mountaineer 1998-2000 4-cylinder Ranger 1998 & Older Ranger

PATS Bypass

I get lots of requests for instruction on how to do a PATS Bypass. Let’s get right to the point; if you have a problem with the transceiver or key, it’s easier and cheaper to replace those parts than to pursue a PATS bypass. Yes, you might need some reprogramming, but most shops and auto locksmiths can do that kind of work these days.

The real problem come in when the PATS module has failed, and you can’t find replacement parts. Then you have two options:

Send the PATS module in to a rebuilder
Pay a company to perform a PATS delete. In that case you most likely have to send your PCM into the company to have them alter the software so it no longer looks for a PATS signal.

Keep Alive Memory (KAM) Reset

The 1999-2000 Ranger 3.0L (only) requires a “Keep Alive Memory (KAM) Reset” after performing the “Parameter Reset” but before programming keys.

Resetting the KAM returns the powertrain control module (PCM) memory to its default setting. Adaptive learning contents such as idle speed, refueling event, and fuel trim are included. Clear the continuous diagnostic trouble codes (DTCs) in the PCM and reset the emission monitors information, is part of a KAM reset. After the KAM has been reset, the vehicle may exhibit certain drivability concerns. It is necessary to drive the vehicle to allow the PCM to learn the values for optimum drivability and performance. This function may not be supported by all scan tools. Refer to the scan tool manufacturer’s instruction manual. If an error message is received or the scan tool does not support this function, disconnecting the battery ground cable for a minimum of 5 minutes may be used as an alternative procedure.

Programing A Blank Key

Following are the instructions for programming a blank key (you must have at least one working key for this procedure).

The PAT

Make sure you have both keys.
Turn on car but don’t start. Watch “theft” indicator until it goes out.
Turn off and repeat procedure with second key.
After “theft light goes out, insert new key and turn on.
Wait until the theft indicator goes off and then turn off switch.
Wait thirty seconds. New key is now programmed into security module. Repeat for any other keys.

Erase any old codes by entering the factory code. (buttons will light up)
Press 1/2 button within 5 seconds.
Press 7/8 and 9/0 buttons at the same time within 5 seconds.

To Set New Code:

Enter factory code (numbers will light up)
Press 1/2 button within 5 seconds.
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.

Enter 5-digit code
While holding 7/8 button in, press and release the 3/4 button.
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 [1] through [5] (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.

Turn the ignition key to ON.
Press the power door UNLOCK control THREE times.
Turn the ignition key from ON to OFF.
Press the power door UNLOCK control THREE times.
Turn the ignition key back to ON. The doors should lock and unlock.
Press the power door UNLOCK control. The horn should chirp ONCE to confirm successful switching of the autolock system

Troubleshooting:

The engine does not start, and LED remains off.

Check PATS system fuses
If alarm is fitted check if LED functions for alarm: if not check cigar lighter fuse (also used for LED)
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:

Code flashes:

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 .