Mechanic Wiki: How to Program a 2005-2007 Chrysler 300 Transponder Key

Learn how to program a 2005-2007 Chrysler 300 transponder key with two working keys, or find locksmith and dealer alternatives. Troubleshoot common issues and FAQs.

Published: June 26, 2026

Quick Answer: How to Program a 2005-2007 Chrysler 300 Transponder Key

To program a new transponder key for a 2005-2007 Chrysler 300, you typically need at least two already-working keys. Insert the first working key, turn the ignition to ON (not start) for 3-5 seconds, then turn it OFF and remove it. Immediately insert the second working key and repeat. Finally, insert the new, unprogrammed key and turn it ON. The security light should turn off, indicating successful programming. If you have only one key or are starting from scratch, you must use a professional locksmith or a dealer-level diagnostic tool.

Understanding Your 2005-2007 Chrysler 300 Key System

Before you grab a new key and start twisting, it pays to understand what's happening under the dash. The 2005-2007 Chrysler 300 uses a Sentry Key Immobilizer System (SKIM) . This system relies on a small transponder chip embedded inside the key head. When you insert the key, the ignition ring antenna reads the chip's unique 49-bit code. If that code matches one stored in the SKIM module, the engine computer (PCM) allows the car to start. If not, the starter and fuel system remain disabled.

There are two main key styles for this generation:

Basic transponder key — a plain metal key with a plastic head containing the chip. No remote locking functions.
Fobik key — an integrated remote fob with a flip-out or separate key blade. It combines the transponder chip and the remote control circuitry in one unit.

The system can store up to eight different key IDs. That's handy if you have multiple drivers or keep a spare in the glovebox. However, the onboard programming method only works if you already have two working keys. Lose all your keys, and you lose the ability to add a new one without professional equipment.

A common mistake: People assume any Chrysler key from 2005-2010 will work. It won't. The 2005-2007 models use a 49-bit chip; later models (2008+) use a 100-bit chip. They are not interchangeable.

Prerequisites for Programming

Gather everything you need before starting. Nothing kills a programming session faster than a dead battery or a key that hasn't been cut yet.

At least two valid, working keys — one must start the car, and the second must at least be recognized by the immobilizer (it should turn the ignition and light up the dash).
A new, uncut, unprogrammed transponder key — the blade must be cut to match your door and ignition locks. Most locksmiths can cut it by code or by copying an existing key.
A fully charged battery in both the car and the key fob (if applicable). Voltage below 12.4V can cause the learning sequence to fail.
A quiet environment — avoid areas with strong radio interference from heavy machinery or power lines, which can disrupt the antenna ring signal.

Pro tip from the field: I always recommend having a third working key if possible. That way, if you make a mistake and lock yourself out of programming, you still have a backup to start the car and try again.

Method 1: Programming With a Working Spare Key

This is the most common and successful method. Follow the steps exactly, paying close attention to timing. The car's computer only enters the learning mode for a brief window after you remove the second key.

Insert the first working key into the ignition. Turn it to the ON position. Do not start the engine. The dashboard warning lights should come on.
Wait 3 to 5 seconds until the security indicator light (a flashing car with a key icon) turns off. This signals the car has recognized the key.
Turn the key to OFF and remove it from the ignition completely.
Immediately insert the second working key within 5 seconds of removing the first key. Turn it to the ON position.
Wait 10 seconds until the security light turns off again.
Turn the key to OFF and remove it.
Immediately insert the new, unprogrammed key within 5 seconds. Turn it to the ON position.
Wait for the security light to turn off (this may take up to 30 seconds). Once it goes out, the key has been learned.
Test the key: Remove it, wait 10 seconds, then insert it again and try to start the car. It should fire right up.

If the security light flashes rapidly or stays on solid during step 8, the learning attempt failed. Don't panic — you can repeat the entire sequence from step 1. The car won't be damaged by multiple attempts.

Timing is everything. I've seen many people fail because they hesitate between removing the second key and inserting the new one. Practice the motion a few times without inserting the new key to get the rhythm down.

Method 2: Programming From Scratch (No Working Keys)

If you've lost all your keys or only have one non-working key, the onboard method will not work. The car requires at least two previously learned keys to enter the programming mode. Without them, you have three options:

Option 1: Hire a Professional Locksmith

Most automotive locksmiths carry specialized tools like the Smart Pro, MVPI, or AutoProPad. These tools can communicate directly with the SKIM module to add a new key. The locksmith will need access to the vehicle's VIN and proof of ownership. Expect to pay between $80 and $150 for a basic transponder key. A fobik key with remote functions will run $150–$250.

Option 2: Visit a Dealership

A Chrysler dealership uses the DRB3 or WiTech diagnostic scanner to program keys. This method is more expensive — often $150–$300 including the key — but it guarantees success. They can also program the remote functions in the same visit.

Option 3: Replace the SKIM Module (Rare)

In extreme cases where the SKIM module itself is faulty (common after water damage or electrical surges), you must replace it. You cannot install a used SKIM from a salvage yard because it will be locked to that car's VIN. You need a new module, which must then be programmed to the PCM. This is a complex job requiring dealer-level tools. Most shops will quote between $400 and $800 for parts and labor.

Detailed Troubleshooting Steps

If your key wasn't programmed on the first attempt, work through these steps methodically. Don't just repeat the same sequence — you'll get the same result.

Step 1: Verify Key Compatibility

Is the chip generation correct? The 2005-2007 Chrysler 300 uses a 49-bit transponder (PATS style). A key from a 2010 Chrylser 300 (100-bit) will not program.
Is the key truly new? A used key from a salvage yard may have its code locked to another car's memory. Even a blank cut key with a previously programmed chip usually can't be overwritten. Buy from a reputable locksmith who provides virgin chips.
Is the blade cut correctly? If the key won't physically turn to ON, you can't even attempt programming. The blade must match your car's lock cylinders.

Step 2: Examine the Security Light Behavior

The security light tells you exactly what's wrong if you know how to read it.

Light Behavior	Meaning	What to Do
Stays on solid	Communication error or low voltage	Check battery voltage. Charge or jump the car.
Flashes rapidly	Chip not being read	Antenna ring may be failing. Clean the ignition cylinder area.
No light at all	SKIM module dead, or key has no chip	Test with a known working key. If still no light, SKIM may need replacement.
Light turns off but car won't start	Key learned, but PCM not communicating	This is rare — may require PCM reflash at dealer.

Step 3: Reset the System

Disconnect the battery for 10–15 minutes. This clears temporary glitches in the SKIM module.
Reconnect and check voltage. Anything below 12.4V is too low. Charge the battery or use a jump pack.
Try the programming sequence again from the beginning.

Step 4: Tighten the "Two Key" Timing

The second key must be inserted and turned to ON within 5 seconds of removing the first key. If you are slow, the car's ECU exits the learning mode. To practice:

Hold the first working key in your right hand, the second in your left.
Remove the first key, immediately grab the second with your right hand, insert, and twist.
Don't worry about the new key yet — practice the exchange three or four times until it feels smooth.

Step 5: Program the Remote Functions Separately

If the key starts the car but the lock/unlock buttons don't work, the transponder chip and the remote are separate circuits. The transponder is learned through the ignition procedure above. The remote must be programmed separately using this method:

Close all doors.
Insert a working key into the ignition and turn to ON.
Turn the key to OFF and remove it.
Press and hold the UNLOCK button on the driver's door panel.
While holding the door switch, press the LOCK and UNLOCK buttons on the new key fob simultaneously for 1 second.
Release the door switch. The door locks should cycle to confirm.
Repeat for each additional fob. The system remembers up to four remote fobs.

Frequently Asked Questions (FAQ)

Q: Can I program a key without any working keys?

A: No. The car requires at least one, and usually two, working keys to enter the learning mode. Without them, you must use a professional locksmith or dealer tool. There is no secret button combination to bypass this requirement.

Q: How much does a locksmith charge to program a Chrysler 300 key?

A: Expect to pay between $80 and $150 for a basic transponder key. A fobik key (with integrated remote) will run $150–$250. This typically includes the cost of the key blank.

Q: My key cuts but won't turn in the ignition. Why?

A: The new key's blade must be cut to match your car's lock cylinders. If it's not cut correctly, it won't turn. This is common when ordering keys online by VIN alone — the dealer or locksmith needs to physically cut it by code. Take it to a local locksmith for precision cutting.

Q: How many keys can I program?

A: The system can store up to eight different key IDs. After eight, you must replace the SKIM module or use a professional tool to erase and re-add keys.

Q: Will replacing the car battery reset the key programming?

A: No. The key programming is stored in non-volatile memory inside the SKIM module. A battery change will not erase the learned keys. The only way to remove a key from memory is to replace the SKIM or use a dealer-level tool.

Q: What does the flashing yellow security light mean?

A: A steady flash (once per second) usually indicates the system is armed and waiting for a valid key. A rapid flash (several times per second) means the system is detecting an invalid key — the chip is not recognized, or the antenna ring is faulty.

Q: My remote works but the car won't start. Is it the key?

A: Yes. The remote function is entirely separate from the immobilizer. If the car won't start, the transponder chip inside the key is likely not communicating, or the chip itself is damaged. The remote could be from a different key or a non-transponder key fob that happens to have a compatible RF frequency.

About the Author: Erwin Salarda is an Automotive Service Equipment Technician based in the Philippines, specializing in computerized automotive diagnostic equipment such as OBD scanners and wheel alignment systems. Since 2012, he has been actively providing technical support, equipment installation, troubleshooting, after-sales service, and hands-on training for automotive service equipment used by workshops and automotive professionals.

He has received specialized training from international suppliers and manufacturers, including Launch X431 in Shenzhen, China, Lawrence Engineering Company in Guangzhou, China, and 3Excel Wheel Alignment Company in Shenzhen, China. Through these trainings, he developed advanced expertise in automotive diagnostics, calibration, wheel alignment systems, and computerized automotive service technologies.

Erwin Salarda provides professional after-sales support and technical training for automotive diagnostic and wheel alignment equipment, helping clients maximize the performance and proper use of their tools and systems. His experience covers equipment setup, software updates, calibration procedures, troubleshooting, and operational guidance for automotive workshops and service centers.

With more than a decade of experience in the automotive equipment industry, Erwin Salarda continues to support automotive businesses by delivering reliable technical expertise and practical training solutions.

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How to Program a 2005-2007 Chrysler 300 Transponder Key | Step-by-Step Guide