In essence the transponder is the key and cylinder, the receiver is what you are referring too. They both work in harmony.

Like in my remote starter, the key is in a transponder and then the coil from that to the ignition switch tells the receiver it is the proper arrangement to start.

Sorry if my wording confused you. Here is a bit more on that

Is the PATS key programmmed for the truck? I believe a rapidly flashing indicates problem with the PATS system. It may indicate a the key is not programmed for the truck, or some other problem with the PATS system.

Here's some additional info on the PATS system:

DIAGNOSIS AND TESTING
Passive Anti-Theft System (PATS) —

Principles of Operation

The ignition key read process is initiated by turning the key to the ON or START position. When a valid PATS key is turned to the ON or RUN
position the PCM queries the PATS transceiver over circuit 1215 (WH/LG). The transceiver then reads the key code and sends the code to the PCM over circuit 1216 (GY/OG). The PCM then validates the read code against stored authorized keys. If the codes match, the PCM then enables the starter using circuit 1785 (LG/VT) and turns on the anti-theft indicator for 3 seconds by applying ground to
circuit 1269 (OG/RD). If the codes do not match, the starter remains disabled and the vehicle does not
start. The PCM then illuminates or rapidly flashes the anti-theft indicator by applying ground to circuit 1269 (OG/RD).

419-01-1 Anti-Theft 419-01-1
DIAGNOSIS AND TESTING
Passive Anti-Theft System (PATS) — Diagnostic Trouble Codes (DTC)

Descriptions
Expanded Diagnostic Trouble Codes (DTC) Descriptions

DTC Expanded Description

B1213 Less than 2 keys programmed to the PATS control. Erase the continuous codes, cycle
the ignition, then carry out the self-test again. If DTCs B1232, B1600, B1601, B1602,
or B1681 are present, they must be serviced first. If DTC B1213 is the only self-test
DTC, program the PATS keys.

B1600 No PATS key read by the PCM. This can be caused by the PATS key, the PATS
transceiver, the circuits between the PATS transceiver and the PCM, and/or the PCM.

B1601 Unprogrammed PATS key. There is no issue with the PATS key itself, but the key
must be programmed into the PATS memory (unless the maximum number of keys are
already programmed). Refer to Key Programming Using Two Programmed Keys in
this section. No parts need to be replaced for this DTC.

B1602 Partial PATS key was read. Make sure that an approved PATS key (Ford, Rotunda,
ILCO, Strattec, HUF, or Valeo) is being used. Large metal objects, additional PATS
keys, or devices used to purchase gasoline located on the customer’s key ring can
cause interference. Instruct the customer to keep such items from touching the ignition
key during engine start. It is not necessary to remove the objects from the customer’s
key ring. Remote starter equipment can also cause this DTC. Remove any remote
starter equipment close to the transceiver before conducting further diagnosis. This
DTC can be caused by the PATS key or the PATS transceiver.

B1681 PATS transceiver module signal is not received by the PCM. This DTC can be caused
by the circuits between the PATS transceiver and the PCM, the PATS transceiver, or
the PCM. Follow the pinpoint test for diagnosis. This can also be caused by using the
incorrect transceiver part number. Make sure that the correct transceiver part number is
being used.

B2103 Transceiver module antenna failure. Replace the transceiver module.

B2431 The ignition key was not programmed. Make sure that the correct key is being used.

 

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