Is Your Sierra Running Rough? Restore Its Power and Reliability.
If your 1999-2000 GMC Sierra 2500 is suffering from perplexing issues like stalling, poor fuel economy, erratic shifting, or a persistent Check Engine Light, the culprit is often a failing Powertrain Control Module (PCM). As the central computer for your truck’s engine and transmission, a faulty PCM can create a cascade of problems that are frustrating to diagnose and can leave you stranded. Don’t let a bad computer sideline your workhorse. This direct-fit replacement PCM is the definitive solution to get your truck back to factory-spec performance and dependability.
This isn’t just a generic, off-the-shelf part. We take the guesswork and hassle out of the replacement process. Upon purchase, you will provide us with your vehicle’s VIN. Our technicians will then program the module with the latest, most stable GM factory software specific to your truck’s configuration. This ensures that when the part arrives, it’s ready for a straightforward installation, communicating perfectly with all your vehicle’s systems right out of the box. This critical programming step prevents the compatibility issues and costly trips to the dealership that are common with un-programmed modules.
From the Diagnostic Bay
We had a 2000 Silverado 2500 (which uses the same PCM) come into the shop with a ghost of a problem. The owner complained of random stalling at traffic lights, but it would always start right back up. There were no consistent trouble codes, just a few random communication errors. We checked fuel pressure, ignition components, and sensors—all tested fine. After hours of diagnostics, we monitored the PCM’s internal temperature data and noticed it would spike just before a stall. A failing processor on the main board was overheating under load. We installed a VIN-programmed 1999-2000 Sierra 2500 PCM, performed the security relearn, and the truck ran flawlessly. It’s a classic example of how a failing computer can mimic a dozen other mechanical issues.
Symptoms of a Failing Powertrain Control Module
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indication that your engine computer needs attention:
- ✔ Unexplained Check Engine Light illumination.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Rough or inconsistent idling.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass emissions testing.
- ✔ Complete no-start condition where the engine cranks but won’t fire.
- ✔ Intermittent loss of power to fuel injectors or spark plugs.
Why Choose a VIN-Programmed Module?
The 1999-2000 Sierra 2500 PCM is the nerve center of your vehicle. It controls everything from the air-fuel ratio and ignition timing to transmission shift points and torque converter lockup. For these systems to function correctly, the computer must have the exact software and calibration for your truck’s specific engine, transmission, and emissions equipment. Our VIN programming service guarantees this compatibility, loading the correct GM-certified calibrations to restore original performance and efficiency. This process is essential for a successful repair and long-term reliability.
This module is a direct replacement for original equipment part numbers 9354896, 09354896, and 19109040. It is also compatible with a wide range of GM vehicles from the same era, including the Silverado, Tahoe, Suburban, Yukon, Camaro, Firebird, and Corvette. Please verify your part number and check the detailed fitment list to ensure this is the correct component for your vehicle.
Installation is typically straightforward. On most 1999-2000 GM trucks, the PCM is located in the engine bay, on the driver’s side, under or near the battery tray. After swapping the hardware, you may need to perform a simple security relearn procedure (often called a CASE relearn) to sync the new PCM with your vehicle’s anti-theft system. This procedure can usually be done without special tools and instructions are widely available.
Frequently Asked Questions
What exactly does the PCM do?
The Powertrain Control Module (PCM) is your vehicle’s main computer. It reads data from dozens of sensors around the engine and transmission to control critical functions like fuel injection, ignition timing, emissions systems, and automatic transmission shifting to ensure optimal performance, fuel economy, and low emissions.
Is programming really necessary for this 1999-2000 Sierra 2500 PCM?
Yes, absolutely. Every vehicle has a unique Vehicle Identification Number (VIN) that corresponds to a specific factory calibration. Programming the PCM with your VIN ensures it has the correct software for your engine, transmission, and options. An un-programmed module will not function correctly and may prevent the vehicle from starting.
Where is this module located on my truck?
On most 1999-2000 Sierra and Silverado 2500 pickups, the PCM is located in the engine compartment on the driver’s side (LH side), typically mounted to a bracket underneath the battery tray.
What is a “security relearn” or “CASE relearn”?
After installing the new PCM, you may need to perform a security relearn procedure. This syncs the new computer with your vehicle’s anti-theft system, allowing the engine to start. A Crankshaft Variation Relearn (CASE) may also be required to calibrate the crank sensor signal for optimal performance and to clear certain trouble codes. The security relearn can often be done by the owner, while the CASE relearn typically requires a capable scan tool.
How do I provide my VIN for programming?
After you complete your purchase, we will contact you for your 17-digit VIN. You can also add it as a note during the checkout process. We cannot ship your part until we have the VIN to program it.