Theft light expedition

You need a good battery. It should read 12.6v while not running and 13.5v + while running. Sounds like a bad cell. Not curable.

Wel the first suspect is the battery, have it tested by a local auto parts store.

Look around the parking lot for another sable the same color... try your key in that one.

try disconnecting the battery negative with the key in the run position..this kills the computer..then shut the key off and reconnect the negative cable, turn the key to run position and listen for the fuel pump to come on 2-3 seconds try to start..repeat this 2-3 times if still an issue.. repost findings

Sounds as if the ignition cylinder is bad. You will have to replace it if the key is stuck. It is a lot easier to replace with the key in the on position as that will be required to remove the cylinder. If you get the key out and then the cylinder will not turn, replacement of the cylinder will be more complicated

I have a 98 Expedition an had the same problem try waiting for the theft light to stop blinking then give it a try it worked for me. Good Luck!!

Turn ignition to run not start,count to 5,turn off key. Repeat this three times. Try to start vehicle. If its starts you are done. If not you will need to repeat turn ignition on count to 5 then turn off, 3 more times On the fourth time leave key in the run position for 10 minutes. Then turn key off & start vehicle.

the light blinks when the system is armed. Normal.

Your key has to be able to communicate with the receiver in the ignition area. Does your other key work ok?

Anti-Theft 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 user.

• During each vehicle start sequence, the ignition key identification code is requested by the PATS module.
• If the key's ID code has been programmed into the system, the vehicle powertrain control module (PCM) (12A650) is allowed to operate; this allows the vehicle to start.
• If the key's ID code is not programmed into the PATS module, or if no encoded key is detected, then the vehicle PCM is disabled.

The PATS module, located under the driver side instrument panel, communicates the state of the security system to the PCM via the module communications network. The PCM, based on the communications from the PATS module, will determine if the vehicle's engine will be enabled to start. If the PCM prevents the vehicle from starting because of PATS, the PCM will store a DTC in memory.
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The anti-theft vehicle protection system utilizes the THEFT indicator, located in the instrument cluster (10849), when the ignition switch is turned to the RUN/START position. The indicator provides system prove out and operating status to the customer or technician.
Each PATS ignition key holds electronics that give each key a unique ID code.
The PATS will activate the indicator signal when the ignition switch is turned to the RUN/START position. The THEFT indicator will turn ON for two seconds, then turn OFF.
If the THEFT indicator flashes for one minute or more, this indicates that there was no key code received.
When the vehicle ignition switch is placed in either RUN or START, the PATS module requests the ignition key ID code. The PATS module requests the ignition key ID code by supplying power, ground, and the carrier signal to the transceiver to energize the ignition key. After the energize period, the key transmits its ID code to the transceiver module, which sends it to the PATS module.
The PATS module then compares the received KEY ID code to those stored in memory (16 maximum). If the ID matches, the PATS module sends an enable signal to the PCM over the module communication network.
The passive vehicle protection system utilizes the engine management capabilities of the PCM to enable or disable the vehicle engine. The module communication network is used to send and receive messages to and from the PCM.
Within one second after engine start, the PCM must receive an enable signal from the PATS module through the module communication network or the engine is disabled before the vehicle can be moved.
If the PATS module recognizes a stored ignition key code but there is a module communication network concern preventing the PCM from recognizing the start enable signal from the PATS module, the vehicle engine will be disabled. If this happens, the PATS module will flash the THEFT indicator for one minute, then flash diagnostic trouble code 16 ten times to indicate there is a problem with the module communication network circuits or the PCM is not responding properly.
The passive vehicle protection system will disable the vehicle from starting if there is a:

• Damaged encoded key.
• Unprogrammed key.
• Non-encoded key (key has no electronics).
• Wiring concern.
• Transceiver concern.
• Control module concern.
• Module communications network concern.
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Key Programming —Spare Key NOTE: Before starting this procedure, make sure the key(s) you want to program have the correct mechanical cut.
NOTE: Performing this procedure does not erase existing programmed keys.

1. Insert the programmed key in the ignition. Turn to RUN.

1. THEFT indicator proves out after two seconds.

1. Remove the programmed key.

1. Within 15 seconds, insert the new key in the ignition and turn to RUN.

1. THEFT indicator proves out after two seconds.

1. The extra key is now programmed.

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Key Programming —New Key (Without Diagnostic Tool) NOTE: Before starting this procedure, make sure the key(s) you want to program have the correct mechanical cut.

1. Insert the nonprogrammed key in the ignition and turn to RUN.

1. THEFT indicator flashes rapidly.

1. After 15 minutes of flashing, the THEFT indicator will stop flashing.

1. Within five minutes after the THEFT indicator has stopped flashing, turn the ignition key to OFF and back to RUN.

1. After 15 minutes of flashing, the THEFT indicator will stop flashing.

1. Within five minutes after the THEFT indicator has stopped flashing, turn the ignition key to OFF and back to RUN.

1. After 15 minutes of flashing, the THEFT indicator will stop flashing.

1. All originally programmed keys are now erased, and only the key in the ignition is programmed.

1. Additional keys may be programmed; refer to Key Programming—Spare Key .

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try locking and unlocking the drivers side door with the key

have to have the key reprogramed. you can try the 3 step cycle. turn the key to run for 10 mins than cycle to off and back on. you have to do 3 10 mins cycle