Is Your Truck Running Rough? Restore Peak Performance.
If your 1999 or 2000 GMC Sierra 1500 is suffering from a persistent check engine light, erratic shifting, stalling, or a no-start condition, a failing Powertrain Control Module (PCM) is often the culprit. As the central computer for your truck’s engine and transmission, its proper function is critical. This direct-fit replacement PCM, part number 16265035, is the definitive solution to get your vehicle running reliably again. We take the guesswork and hassle out of the repair by programming the module specifically to your truck’s Vehicle Identification Number (VIN) before it ships. This ensures 100% compatibility and a true plug-and-play installation experience.
From the Diagnostic Bay
We had a 2000 Silverado come in that had its owner chasing ghosts for weeks. The truck would randomly stall at stoplights and had a check engine light with a handful of seemingly unrelated sensor codes. The owner had already replaced the throttle position sensor and a couple of O2 sensors with no luck. After hooking up our professional scan tool, we noticed the live data stream from the PCM was dropping out intermittently. This confirmed our suspicion: the computer itself was failing internally. We installed a VIN-programmed module just like this one, performed a quick security relearn, and the truck ran perfectly. It’s a classic case where throwing parts at the problem costs more than correctly diagnosing a faulty module first.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) that won’t clear or returns immediately.
- ✔ Engine stalling, stumbling, or misfiring for no apparent reason.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Complete no-start condition where the engine cranks but won’t fire up.
- ✔ Failure to communicate with diagnostic scan tools.
- ✔ Illumination of other warning lights on the instrument cluster.
The Importance of a VIN-Programmed 1999-2000 Sierra 1500 PCM
Unlike many other parts on your truck, a PCM is not a one-size-fits-all component. It must be programmed with the correct software for your vehicle’s specific engine, transmission, and options. Our process eliminates the need for an expensive trip to the dealership for programming. Simply provide us with your VIN during or after checkout, and our technicians will flash the module with the latest GM-certified software updates. This ensures your engine and transmission operate at optimal efficiency and performance, just as the factory intended. This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, and others, offering broad compatibility across many GM trucks and vans of the era.
Installation is straightforward for any DIY mechanic or professional technician. After disconnecting the battery, simply unbolt the old module, disconnect the wiring harnesses, and install the new one. In many cases, a simple security relearn procedure (often called a CASE relearn) may be required, which can be done without special tools. Getting this essential component for your 1999-2000 Sierra 1500 PCM is the most effective way to solve complex electronic issues and restore your truck’s dependability.
Frequently Asked Questions
Do I need to get this module programmed?
No. We handle all the programming for you before we ship the part. Just provide your vehicle’s VIN, and it will arrive ready to install with the latest GM software.
Where do I find my vehicle’s VIN?
Your 17-digit 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.
What is a security or CASE relearn procedure?
This is a simple procedure that syncs the new PCM with your vehicle’s anti-theft system and crankshaft position sensor. It typically involves a sequence of turning the key on and off and can be done in your driveway without any special tools. Instructions are widely available online for your specific model.
Is this a direct replacement for my original part?
Yes, this module is a direct-fit replacement for OEM part number 16265035 and other compatible part numbers listed. It will mount and connect just like your original factory unit.
What happens if I install it without programming?
An unprogrammed module will not work correctly. It will likely cause a no-start condition and set multiple trouble codes because it cannot communicate with the other systems in your vehicle. Our mandatory VIN programming service prevents this issue entirely.