Restore Peak Performance to Your GM Truck or Van
Is your Chevrolet, GMC, or Cadillac suffering from frustrating issues like a persistent check engine light, erratic transmission shifting, poor fuel mileage, or a no-start condition? These are classic signs of a failing Powertrain Control Module (PCM), the central computer of your vehicle. As an experienced technician, I’ve seen firsthand how a faulty PCM can cause a cascade of problems that are difficult to diagnose. This module is the direct-fit, reliable solution to get your vehicle running smoothly again, without an expensive trip to the dealership for programming.
This isn’t just a replacement part; it’s a complete solution. We flash this PCM with the latest official GM software updates, tailored specifically to your vehicle’s Vehicle Identification Number (VIN). This ensures perfect communication between your engine, transmission, and other onboard systems, restoring the original performance and efficiency you expect from your truck. By providing your VIN at checkout, you receive a module that is truly plug-and-play, eliminating one of the biggest headaches in modern auto repair.
A Technician’s Notebook: The Intermittent No-Start Nightmare
I remember a 2000 GMC Sierra that came into my shop with a maddeningly intermittent no-start problem. The owner had already replaced the battery, starter, and fuel pump. It would start fine for a week, then leave him stranded. After hooking up my scan tool during one of its ‘bad’ moments, I saw no communication with the PCM. A wiggle test on the PCM connectors didn’t change anything. We tested power and grounds to the module—all perfect. The culprit was internal to the 1999-2000 Chevrolet 2500 PCM itself; thermal stress had caused a hairline crack in a circuit board that only opened up when the module was hot. A replacement, pre-programmed PCM like this one solved the problem permanently. It’s a reminder that sometimes the ‘brain’ is the source of the most elusive issues.
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. Look out for these signs and associated Diagnostic Trouble Codes (DTCs):
- ✔ Check Engine Light is illuminated with codes like P0601, P0604, or P0606 (Internal Module Failure).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine stalling or misfiring randomly.
- ✔ Failure to pass state emissions testing.
- ✔ Loss of communication with the scan tool.
A Straightforward Guide to Installation
Installing your new 1999-2000 Chevrolet 2500 PCM is a manageable job for a DIYer with basic tools. Following these steps will ensure a smooth process.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect the Connectors: Carefully unclip and remove the large electrical harness connectors from the old PCM. These connectors have locking tabs that need to be released before pulling.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely re-fasten the bolts.
- Reconnect Everything: Firmly plug the electrical connectors into the new module until they click into place. Reconnect your battery’s negative terminal.
- Perform Security Relearn: For many GM vehicles of this era, a security relearn (often called a Passlock relearn) is necessary. The typical procedure is: Turn the key to ‘ON’ for 10-15 minutes, then ‘OFF’ for 10 seconds. Repeat this cycle 3 times. The vehicle should then start.
Verified Vehicle Compatibility
This module is a direct replacement for service number 16265035 and is also compatible with part numbers 16263494, 8162634940, 218-11787, and 21811787. It is guaranteed to fit the following gasoline-engine GM models:
GMC: 1500/2500/3500 Pickups (99-00), Sierra 1500 (99-00), Sonoma (98-00), Jimmy (98-00), Safari Van (99-01), Savana Van 1500/2500/3500 (99-02), Yukon/Yukon Denali (99-00)
Cadillac: Escalade (99-00)
Oldsmobile: Bravada (98-00)
Isuzu: Hombre (98-00)
GMC/Chevrolet Medium Duty: Envoy (98-00)
Note: Please verify your specific model options and part number ID against this list. The correct 1999-2000 Chevrolet 2500 PCM is critical for proper function.
Frequently Asked Questions
How does the VIN programming work?
After you place your order, you simply provide us with your 17-digit VIN. Our technicians use this number to access the latest GM software for your exact vehicle configuration and flash it onto the module before shipping. This ensures it works correctly right out of the box.
Do I need any special tools for installation?
No special tools are required. Basic hand tools like a socket set and ratchet are all you need to physically swap the module. The only other procedure is the key-cycle security relearn, which requires no tools at all.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls the transmission’s shift points and line pressure. If the module is failing, it can cause hard shifts, delayed shifting, or hunting for gears. A new, correctly programmed PCM often resolves these issues.
Is this a used part?
This is a high-quality, inspected, and tested component that has been verified to meet or exceed original equipment specifications. It is then loaded with fresh, vehicle-specific software.
What if I have questions during installation?
We’re here to help. Our team of experienced professionals can provide guidance to ensure you get your vehicle back on the road. Customer support information is included with your order.