2002 mercury mountaineer stalled while in gear will not engage the starter coil pack all fuses relays dtr pcm starter pat ignition tumblers or ignition switch left to troubleshoot help please

The PATS anti-theft system will not let the starter engage an spin the engine around to start the vehicle if the theft deterrent module does not get correct coded value from the pats key. There is a transponder in the head of the key - when put into the lock cylinder a antenna behind the plastic steering column energizes the transponder which makes it send it's unique code to the computers on the vehicle. You have no clue what you're doing . Take it to a qualified repair shop .

You would need a factory scan tool to check for codes in the computers before just replacing parts. Changing the ignition ? lock & key assemble or the electrical part of ignition switch? If key an lock cylinder the key needs to be programmed into the control modules .

Anti-Theft NOTE: If the instrument cluster or the PCM (or both) is installed, the parameters must be reset in both modules or the vehicle will experience a passive anti-theft system (PATS) no-start. For additional information, refer to Passive Anti-Theft System (PATS) Parameter Reset in this section.
PATS consists of the following components:

• Anti-theft indicator (located in the autolamp/sunload sensor)
• Encoded (the key contains a transponder) ignition key
• PATS transceiver
• Instrument cluster
• Powertrain control module (PCM)

PATS uses radio frequency identification technology to deter a drive-away theft. Passive means that it does not require any activity by the user.
The vehicle is equipped with 2 PATS keys. A maximum of 8 PATS keys can be programmed to start the vehicle. If additional PATS keys are desired, refer to Spare Key Programming - Unlimited Key Mode in this section.

. quick flashing when ? when trying to start the vehicle ? If yes you need to have it checked for codes . Do you know what DTC'S - diagnostic trouble codes are . If that light is flashing while trying to start the vehicle codes are present in the module that controls PATS . Instead of guessing have towed to a qualified repair shop . Because you have no idea how to diagnose this system .

PATS uses a visual theft indicator. This indicator will prove out for three seconds when the ignition switch is turned to RUN or START under normal operation. If there is a PATS problem, this indicator will either flash rapidly or glow steadily when the ignition switch is turned to RUN or START. PATS also "blips" the theft indicator every two seconds at ignition OFF to act as a visual theft deterrent.

Awd merc 02 ????? Mercury what ? Transmission range switch is input to the PCM . If the PCM thinks it's in gear I would look at this part . Read input data from range switch to PCM on a scan tool that can do that . Transceiver for Pats is around the ignition lock cylinder behind plastic cover ,

If you want help you need to explain a little better . When you turn the key to start , the starter doesn't engage , correct ? On top of the instrument pane is there a little red light flashing when you try starting the vehicle ? Need to know model so I can look at wiring diagram .

10.55 volts is an indication of a flat battery as the voltage should be 12 volts. Have a load test done on the battery to check for failed cell

According with the manual, check in the Passenger compartment fuse panel; the fuse panel is located below and to the left of the steering wheel by the brake pedal. Remove the panel cover to access the fuses...



Position 10 with 20AAMP for PCM Relay, Ignition Coil, PATS, Radio

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Fuse/Relay Location Amp Rating


1 20A Moonroof, Adjustable pedals, DSM, Memory lumbar motor 2 5A Microcontroller power (SJB) 3 20A Radio 4 20A OBD II connector 5 5A Moonroof 6 20A Liftglass release motor, Door unlock/lock 7 15A Trailer stop/turn 8 15A Ignition switch power, PATS 9 2A 6R TCM/PCM (Ignition RUN/START), Fuel pump relay 10 5A Front wiper RUN/ACC relay in PDB 11 5A Radio start 12 5A Rear wiper motor RUN/ACC, Trailer battery charge relay in PDB, Radio 13 15A Heated mirror, Rear defrost indicator 14 20A Horn 15 10A Reverse lamps 16 10A Trailer reverse lamps 17 10A RCM, PAD lamp, OCS module 18 10A Reverse park aid, IVD switch, IVD, AWD module, Heated seat switches, Compass, Electrochromatic mirror, AUX climate control 19 - Not used 20 10A Manual climate, DEATC, Brake shift 21 - Not used 22 15A Brake switch, Stop lamps, Turn lamps 23 15A Power mirrors, Interior lamps, Puddle lamps, Battery saver, Instrument illumination, Homelink 24 2A Cluster, Theft LED 25 15A Trailer park, Trailer electronic brake module 26 15A License plate/rear park lamp, Front park lamps, Manual climate 27 15A Tricolor stop 28 10A Manual/DEATC CB1 25A Windows

When the anti-theft light is flashing rapidly then either it is not seeing the key,or the transciever module is not communicating with the PCM. It could be the transciever or it could be the PCM is not powering up for some reason. I would first try replacing the PCM relay in the underhood fuse panel.

The power distribution box is
located in the engine compartment.
The power distribution box contains
high-current fuses that protect your
vehicle’s main electrical systems
from overloads.
The starter relay is in position #56 of that box.