2015 Kenworth T680 Key Fob Programming Guide

Heavy-duty trucks require heavy-duty security. If you are an owner-operator or fleet manager running a 2015 Kenworth T680, dealing with a lost or damaged key fob can mean expensive downtime. As an ASE-certified electrical technician and locksmith, I’ve worked on numerous commercial systems. Unlike standard passenger vehicles, commercial trucks utilize specialized modules that require heavy-duty diagnostic software.

Here is everything you need to know about replacing, programming, and maintaining the key fob and ignition key for a 2015 Kenworth T680.

Quick reference

Item	Detail
FCC ID	Varies by specific build (Verify via VIN or original fob)
OEM Fob PN	PACCAR specific (Typically Q21-series, verify via VIN)
Aftermarket Options	Highly limited; OEM recommended
Battery Type	CR2032
Programmable On-Board?	No (Requires PACCAR ESA Software)
Cuts Required?	Yes, mechanical ignition key must be cut

Step-by-step on-board programming

Unlike many older passenger cars, the 2015 Kenworth T680 does not support DIY on-board programming for its remote keyless entry or immobilizer system.

Because commercial trucks are high-value assets carrying valuable cargo, PACCAR (the parent company of Kenworth) engineered the Body System Controller (BSC) and Cab Electronic Control Unit (CECU) to require secure, authorized software for key and remote pairing.

To program a new key or fob to your T680, you or a technician must use PACCAR ESA (Electronic Service Analyst) diagnostic software paired with a compatible heavy-duty Nexiq USB-Link or similar interface.

Here is the general procedure a certified technician will follow:

1. Connect the heavy-duty diagnostic interface (e.g., Nexiq) to the truck's 9-pin diagnostic port.
2. Launch the PACCAR ESA software and establish communication with the vehicle's CECU.
3. Navigate to the "Program Keys/Remotes" or "Security" module within the software.
4. Clear missing or lost keys from the system to prevent unauthorized access.
5. Follow the on-screen prompts to pair the new transponder key and/or remote fob to the truck's receiver.
6. Cycle the ignition as commanded by the software to finalize the pairing.
7. Test all buttons (Lock, Unlock, Panic) and verify that the truck starts without immobilizer faults.

If you do not have a $1,000+ heavy-duty diagnostic setup and a PACCAR software license, you cannot program this fob yourself.

Battery replacement

Even heavy-duty fobs rely on standard power sources. When your Kenworth remote's range drops or it stops working intermittently, the battery is likely the culprit.

1. Locate the small notch or seam on the side of the plastic key fob casing.
2. Insert a small flathead screwdriver or plastic pry tool into the notch and gently twist to separate the two halves of the shell.
3. Remove the internal circuit board to access the battery on the back, or lift the battery directly from its housing.
4. Remove the old battery and note its orientation.
5. Insert a fresh CR2032 3V lithium battery, ensuring the positive (+) side is facing the correct direction (usually face up).
6. Snap the two halves of the fob shell back together firmly.
7. Test the fob near your truck. Replacing the battery will not erase the fob's programming.

Where to buy a replacement fob

When procuring parts for a commercial truck, reliability is non-negotiable.

• Kenworth Dealer: This is the most reliable route. The dealership will match your VIN to ensure you get the exact PACCAR part number required for your specific build. Pros: Guaranteed compatibility and warranty. Cons: Most expensive option.
• Commercial Locksmiths: Locksmiths specializing in heavy-duty and fleet vehicles can source OEM remotes and cut the mechanical keys on-site. Pros: Mobile service saves you from towing the rig. Cons: Finding a locksmith with PACCAR software can take a few phone calls.
• Online/Amazon: While you might find heavy-duty remotes online, it is highly risky. Commercial truck electronics vary wildly based on the original fleet order. An incorrect aftermarket fob will not communicate with your truck’s CECU. Expect to pay around $100–$250 for the part itself, depending on whether it's a standalone remote or integrated transponder key.

If on-board programming isn't supported

Since the 2015 Kenworth T680 requires professional programming, you must budget for labor and service call fees.

If you drive the truck to a Kenworth dealership, expect to pay between $150 and $300 for an hour of diagnostic labor, plus the cost of the key and fob. If all keys are lost and the truck is stranded at a truck stop or yard, towing a commercial rig is incredibly expensive.

In a "lost all keys" scenario, your best bet is to call a mobile commercial locksmith. They can cut a new transponder key by decoding your door or ignition cylinder, plug into your 9-pin port, and program the immobilizer on the spot. Mobile commercial locksmith fees usually range from $250 to $500 depending on mileage and after-hours emergency rates, but this is far cheaper than a heavy-wrecker tow to the dealership.

Find a mobile locksmith or shop on Repairius.