Restore Peak Performance to Your GM Truck or Van
Is your trusty GMC 3500, Chevy Silverado, or Express van suddenly giving you headaches? Unexplained stalling, a persistent Check Engine Light, or erratic transmission shifts can be incredibly frustrating. As a technician with over two decades of experience, I’ve seen these symptoms countless times. More often than not, the root cause isn’t a dozen different failing sensors—it’s the vehicle’s brain, the Powertrain Control Module (PCM), that’s failing. This replacement PCM, part number 16265035, is the reliable, straightforward solution to get your vehicle running properly again.
The biggest hurdle in replacing a PCM has always been the expensive and time-consuming programming required at a dealership. We eliminate that step entirely. When you purchase this module, we flash it with the latest official GM software updates, specifically matched to your vehicle’s VIN. This means it arrives at your door ready for installation, saving you time, money, and the hassle of a tow. This isn’t just a replacement part; it’s a complete solution designed for both professional mechanics and determined DIYers.
From the Diagnostic Bay: The Ghost in the Machine
I remember a 2000 GMC 3500 work truck that came into my shop. The owner was at his wit’s end. He’d been to two other places for an intermittent no-start and a transmission that would randomly refuse to shift out of first gear. No codes were stored consistently. We checked the wiring, grounds, and power feeds to the PCM—all solid. On a hunch, I monitored the 5-volt reference signal from the PCM while tapping on the module case. Sure enough, the voltage would drop out sporadically. The internal circuits were failing under vibration and heat. We installed a VIN-programmed PCM just like this one, and the truck ran flawlessly. It’s a classic failure mode for these units, and a new module is the only correct fix.
Is Your Truck Exhibiting These Symptoms?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, this module is likely the solution you need:
- ✔ Persistent Check Engine Light with codes such as P0601, P0602, or P0605 (Internal Module Errors).
- ✔ Vehicle refuses to start or stalls intermittently.
- ✔ Harsh, erratic, or delayed transmission shifting.
- ✔ A noticeable decrease in fuel economy.
- ✔ Communication errors with your scan tool.
- ✔ Misfires or rough idling that can’t be traced to plugs, coils, or injectors.
A Straightforward Guide to Installation
Replacing the PCM on these GM trucks and vans is a job most people with basic tools can handle in under an hour. Our pre-programming makes it even simpler.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- Locate the PCM: On most trucks like the GMC 3500, you’ll find the PCM in the engine compartment on the driver’s side, near the firewall or battery. On vans like the Express/Savana, it’s often in the LH rear of the engine compartment.
- Disconnect the Old Module: Carefully unplug the electrical connectors. These usually have a locking tab or lever that needs to be released. Avoid pulling on the wires themselves.
- Remove the Module: Unbolt the old PCM from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed PCM into place and securely reconnect all electrical connectors. Ensure they click into place.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn (If Needed): In some cases, you may need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating a few times. Your vehicle’s service manual will have the exact steps.
Verified Vehicle Compatibility
This module, service number 16265035, is a direct replacement for part numbers 16263494, 8162634940, 218-11787, and 21811787. It fits a wide range of GM vehicles, including but not limited to:
- Cadillac: Escalade (1999-2000)
- Chevrolet: Astro Van (1999-2001), Blazer S10 (1998-2000), C/K 1500/2500/3500 Pickup (1999-2000), Express Van 1500/2500/3500 (1999-2002), S10 Pickup (1998-2000), Silverado 1500 (1999-2000), Suburban 1500/2500 (1999), Tahoe (1999-2000)
- GMC: C/K 1500/2500/3500 Pickup (1999-2000), Envoy (1998-2000), Jimmy S15 (1998-2000), Safari Van (1999-2001), Savana Van 1500/2500/3500 (1999-2002), Sierra 1500 (1999-2000), Sonoma S15 (1998-2000), Yukon & Yukon Denali (1999-2000)
- Isuzu: Hombre (1998-2000)
- Oldsmobile: Bravada (1998-2000)
Important: Please verify your original part number or send us your VIN to confirm compatibility before ordering.
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming for you before shipment. We flash the module with the latest GM software using the VIN you provide, so it’s ready to install right out of the box.
How do I provide my Vehicle Identification Number (VIN)?
After you complete your purchase, simply send us a message with your 17-digit VIN. We cannot ship your order until we receive this information, as it’s essential for correct programming.
Where is the PCM located on my 2000 GMC 3500 Pickup?
On the 1999-2000 GMC/Chevy 3500 gasoline pickups, the Electronic Control Module is located in the engine compartment on the driver’s side (LH side).
What is a security relearn procedure?
This is a simple, key-on/key-off sequence that syncs the new PCM with your vehicle’s anti-theft system. It doesn’t require any special tools and instructions can be easily found online or in your owner’s manual for your specific model.
Is this a reliable part?
Absolutely. We provide a dependable, tested module that is programmed to meet or exceed original factory specifications, ensuring a lasting repair for your vehicle.