Restore Peak Performance to Your GM Van or Truck
Is your Chevrolet Express or GMC Savana suffering from frustrating, hard-to-diagnose issues? Stalling at intersections, erratic shifting, a persistent Check Engine Light, or a no-start condition can bring your work or travels to a grinding halt. As a technician with over two decades of experience, I’ve seen these symptoms countless times, and they often point to one component: a failing Powertrain Control Module (PCM), the computer brain of your vehicle.
This isn’t just a replacement part; it’s a complete, reliable solution. We provide a high-quality Powertrain Control Module specifically programmed to your vehicle’s unique Vehicle Identification Number (VIN). This critical step ensures all communications between the engine, transmission, and other systems are restored to factory specifications. We install the latest GM-authorized software updates, which can often resolve performance issues the original programming had. This is the same service a dealership provides, but without the high cost and scheduling headaches.
A Technician’s Notebook
I remember a 2001 Express 2500 work van that came into my bay with the most bizarre, intermittent problems. The owner, a plumber, said it would run fine for days, then suddenly start misfiring and lose power, only to correct itself an hour later. He’d already replaced plugs, wires, and a coil pack with no luck. We hooked up the scanner and found no hard codes, just some strange communication history. On a hunch, we monitored the PCM’s power and ground feeds while tapping on the module. Sure enough, the data stream would flicker. A hairline crack in the circuit board, likely from years of heat cycles and vibration, was the culprit. A new, properly programmed PCM like this one had his van back on the road reliably the same day, saving him from losing more business.
The Core of Your Vehicle’s Operation
The PCM is the central command for your entire powertrain. It takes data from dozens of sensors—like the crankshaft position, oxygen sensors, and throttle position—and makes thousands of calculations per second to manage fuel injection, ignition timing, and transmission shift points. When it fails, the symptoms can be widespread and confusing. Installing our pre-programmed 1999-2002 Express 2500 PCM is a direct and effective way to fix these root-cause electrical problems and restore the dependable performance your vehicle was built for.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
- ✔ Locate the PCM: On most Express/Savana vans, the PCM is located in the engine compartment on the driver’s side, near the firewall or battery. On other GM models, it may be on the passenger side or under the battery tray. Check your specific model’s layout.
- ✔ Disconnect the Harnesses: Carefully unclip and disconnect the large electrical wiring harnesses from the old PCM. These connectors have locking tabs that must be released before pulling. Do not force them.
- ✔ Remove the Old Module: Unbolt the PCM from its mounting bracket. There are typically a few bolts or nuts holding it in place.
- ✔ Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it with the original bolts.
- ✔ Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect your vehicle’s negative battery terminal.
- ✔ Perform Security Relearn (If Necessary): In many cases, you will need to perform a simple security relearn procedure to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Instructions are readily available online for your specific model.
Is Your GM Truck or Van Showing These Symptoms?
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Intermittent stalling or rough idling for no apparent reason.
- ✔ The vehicle fails to communicate with a diagnostic scan tool.
Verified Vehicle Compatibility
This module is a direct-fit replacement for a wide range of GM trucks and vans. It is compatible with part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. Please verify your vehicle is on the list below. Providing your VIN during checkout is essential for us to ensure perfect programming and compatibility.
Fitment includes, but is not limited to: Chevrolet Express 1500/2500/3500, GMC Savana 1500/2500/3500, Chevrolet Silverado, GMC Sierra, Tahoe, Yukon, Suburban, S10, Blazer, Astro, Safari, and more from approximately 1998-2002. Match your part number or contact us with your VIN.
Frequently Asked Questions
Do I need to do anything after I install this PCM?
After installation, you will likely need to perform a simple security relearn procedure, also known as a “CASE learn” or “Passlock relearn.” This syncs the new module to your vehicle’s anti-theft system and can typically be done in your driveway in about 30 minutes with just your ignition key. Specific instructions for your model are widely available online.
How do I provide my VIN for programming?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot ship your part until we receive this information, as the programming is essential for the module to function in your vehicle.
Is this a guaranteed fix for my vehicle’s problems?
While this 1999-2002 Express 2500 PCM resolves the vast majority of issues listed, proper vehicle diagnostics are always recommended. A PCM is often the cause of these symptoms, but you should ensure other components like wiring, sensors, and power/ground connections have been checked by you or your mechanic.
What if my original part number is slightly different?
This module replaces several part numbers, including 16263494 and 16265035. As long as your vehicle is on the compatibility list and you provide a valid VIN, we will program it to function correctly for your specific application.
Will this fix my poor gas mileage?
In many cases, yes. A failing PCM can cause poor fuel mixture and timing calculations, leading to reduced efficiency. By installing a module with the latest software and correct parameters, you restore the engine’s ability to run as efficiently as designed.