Restore Peak Performance to Your GM Truck or Van
Is your trusty GMC 3500, Chevy Silverado, or Express van suddenly giving you headaches? If you’re dealing with a persistent Check Engine light, erratic engine behavior, stalling, or a complete no-start condition, the Powertrain Control Module (PCM) is a likely culprit. As the central computer of your vehicle, when it fails, it can cause a host of frustrating and hard-to-diagnose problems. This isn’t just a replacement part; it’s a direct solution to get your workhorse running reliably again.
We take the guesswork and hassle out of the repair. Unlike a generic module from a parts store or salvage yard, this PCM is professionally flashed with the latest official GM software updates. All we need is your vehicle’s VIN. This ensures that when the module arrives at your door, it’s a true plug-and-play component, perfectly matched to your truck’s specific configuration. You get improved performance and reliability without the expensive trip to a dealership for programming. This is the definitive fix for a failing 1999-2000 GMC 3500 PCM and many other compatible GM vehicles.
From the Diagnostic Bay
I remember a 2000 Chevy 2500 that came into my shop on a tow truck. The owner had already replaced the fuel pump and crankshaft position sensor trying to solve an intermittent stalling issue that finally became a permanent no-start. The scanner couldn’t even communicate with the PCM—a dead giveaway. These older PCMs are prone to internal solder joint failure from years of heat cycles and vibration. We installed one of our pre-programmed modules, and the truck fired up on the first try and ran smoother than it had in years. The owner saved hundreds by avoiding a dealership and the ‘parts cannon’ approach.
Is Your GM Truck or Van Showing These Signs?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, this module is the likely solution your vehicle needs:
- ✔ Check Engine Light is on with communication error codes (e.g., U0100) or internal processor fault codes (P0601, P0602, P0606).
- ✔ The engine cranks but will not start.
- ✔ Rough or unpredictable idling and stalling.
- ✔ A noticeable drop in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass an emissions inspection.
- ✔ Intermittent issues that seem to have no other cause.
A Straightforward Guide to Installation
For most DIYers with basic tools, this is a very manageable job. Getting your 1999-2000 GMC 3500 PCM replaced can take less than an hour.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most trucks like the GMC 3500 or Silverado, the PCM is located in the engine compartment on the driver’s side, near the firewall or inner fender. On vans like the Express or Savana, it’s often in the LH rear of the engine compartment.
- Disconnect the Connectors: Carefully unclip the wiring harness connectors from the old PCM. There are typically multiple color-coded connectors with locking tabs. Be gentle to avoid damaging the pins or clips.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware as you will reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely re-fasten the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the correct slots on the new module. You’ll hear a click as they lock into place. Reconnect the negative battery terminal.
- Final Step (If Needed): In some cases, a Crankshaft Position System Variation (CASE) relearn procedure is required to clear a P1336 code. This can be done with many professional-grade scan tools and ensures the engine runs its absolute best.
Verified Vehicle Compatibility
This module is a direct replacement for part number 16263494 and is also compatible with part numbers 16265035, 8162634940, 218-11787, and 21811787. It fits a wide range of GM vehicles, including but not limited to:
- Chevrolet/GMC C/K 1500, 2500, 3500 Pickups (1999-2000)
- Chevrolet Silverado & GMC Sierra 1500 (1999-2000, 4.3L V6)
- Chevrolet Tahoe & GMC Yukon (1999-2000)
- Cadillac Escalade (1999-2000)
- Chevrolet Suburban 1500 & 2500 (1999)
- Chevrolet Express & GMC Savana Vans 1500, 2500, 3500 (1999-2002)
- Chevrolet Astro & GMC Safari Vans (1999-2001)
- Chevy S10, GMC Sonoma, Jimmy, Blazer, Olds Bravada, Isuzu Hombre (1998-2000, 4.3L)
Please verify your original part number or contact us with your VIN to ensure perfect fitment for your specific model and options. This is the correct solution for your 1999-2000 GMC 3500 PCM repair.
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming before we ship the module. It will arrive ready to install, flashed to your vehicle’s specific VIN with the latest GM software.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to access the exact factory calibration file for your truck’s engine, transmission, and emissions equipment. This ensures perfect compatibility and performance.
Is this a simple plug-and-play installation?
Yes, for most vehicles. After installation, the security system may need to complete a simple key relearn procedure, which typically involves cycling the key. In some cases, a CASE relearn with a scan tool is recommended for optimal performance.
How do I find my original part number?
The part number is printed on a sticker on the case of your current PCM. It will typically be a large, bold number like 16263494.
Will this fix my P0601 error code?
Yes. A code P0601 (Internal Control Module Memory Check Sum Error) is a definitive sign of internal PCM failure. Replacing the module with this pre-programmed unit is the correct repair for this code.