Restore Peak Performance to Your GM Truck or Van
Is your 1999-2000 Silverado 1500 running rough, shifting erratically, or showing a persistent Check Engine Light? You’re not just dealing with an annoyance; you’re facing a failure of the vehicle’s central command center. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can create a cascade of frustrating and hard-to-diagnose issues. This isn’t just a part; it’s the brain of your engine and transmission, and when it falters, your truck’s reliability and efficiency go with it.
This replacement PCM, part number 16263494, is the definitive solution. We take the guesswork and dealership hassle out of the equation. Before this module ships, our experts will program it with the latest official GM software updates, specifically matched to your vehicle’s VIN. This ensures that all factory parameters for fuel delivery, ignition timing, and transmission shifting are perfectly restored. You’re not just getting a replacement; you’re getting a component that’s ready to install right out of the box, solving complex electronic problems without requiring an expensive trip to the dealer for programming.
A Technician’s Notebook: The Ghost in the Machine
I remember a 2000 GMC Sierra that came into my bay with a no-start condition that had stumped two other shops. The owner had already replaced the fuel pump and crank sensor. All the basics checked out—fuel pressure was good, spark was present, but it just wouldn’t fire. After hooking up my high-level scanner, I noticed erratic data from multiple sensors, but no specific codes pointing to a single component. This is a classic sign. The PCM itself was corrupt, sending out garbage signals. We installed a VIN-programmed 1999-2000 Silverado 1500 PCM (the same family as this unit), and the truck fired up on the first turn of the key. It’s a powerful reminder that the PCM is the foundation of your engine’s operation.
Is Your Truck Showing These Symptoms?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your module may need replacement. Catching it early can prevent further damage to other components like your catalytic converter.
- ✔ Check Engine Light is illuminated with codes like P0601 (Internal Memory Error) or P0606 (PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or delayed automatic transmission shifts.
- ✔ The engine stalls intermittently or idles erratically.
- ✔ Failure to pass state emissions testing.
- ✔ Communication errors with diagnostic scan tools.
A Straightforward Guide to Installation
Replacing the 1999-2000 Silverado 1500 PCM is a job most DIYers can handle in their own driveway. Since we program it for you, no special electronic tools are needed for the installation itself.
- Safety First: Disconnect the negative terminal from your truck’s battery to prevent any electrical shorts.
- Locate the PCM: On most 1999-2000 Silverado/Sierra 1500 models with the 6-cylinder engine, the PCM is located in the engine compartment on the driver’s side, often under or near the battery tray.
- Disconnect Wiring: Carefully unclip and remove the electrical harness connectors from the old PCM. These connectors have locking tabs; be gentle to avoid breaking them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need it for the new module.
- Install the New PCM: Mount your new, pre-programmed module in place and securely tighten the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new PCM until they click into place. Reconnect the negative battery terminal.
- Final Steps: Some vehicles may require a security relearn procedure, which typically involves turning the key to the ‘On’ position for 10-15 minutes. Consult your vehicle’s service information for specific steps if needed. Start the engine and verify the Check Engine Light is off and the truck runs smoothly.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It is guaranteed to fit a wide range of GM trucks and vans. While we’ve targeted the 1999-2000 Silverado 1500 PCM, please check the extensive list below to confirm fitment for your specific vehicle and engine configuration. Matching the part number on your original module is the best way to ensure compatibility.
Fitment includes, but is not limited to:
- Silverado/Sierra 1500 (99-00, 6-Cyl)
- S10/S15/Sonoma/Hombre (98-00, 4.3L)
- Blazer/Jimmy/Bravada/Envoy (98-00)
- Astro/Safari Van (99-01)
- Express/Savana Van 1500/2500/3500 (99-02)
- Tahoe/Yukon/Escalade (99-00)
- And various other GM pickups. Please verify your part number.
Frequently Asked Questions
Do I need to do any programming after I receive this PCM?
No. We program the module to your specific VIN before shipping. It arrives ready for installation, saving you a trip to the dealership.
Where do I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on a metal plate on the driver’s side of the dashboard, visible through the windshield.
Is this a simple plug-and-play installation?
Yes, for the most part. After physically installing the module, some vehicles may require a simple security or CASE relearn procedure, which can often be done without special tools. The core engine and transmission functions will work immediately.
Will this fix my transmission shifting problems?
If the shifting issues are caused by faulty electronic commands from a failing PCM, then yes. The PCM controls shift points and line pressure. A new, correctly programmed module restores these functions to factory specifications.
What is the difference between a PCM, ECM, and ECU?
The terms are often used interchangeably. ECM (Engine Control Module) typically just controls the engine. PCM (Powertrain Control Module) controls both the engine and the transmission. ECU (Electronic Control Unit) is a more generic term. For this generation of GM trucks, PCM is the most accurate term.