Restore Peak Performance to Your GM Truck or Van
If you’re dealing with frustrating engine problems in your 1999-2002 Chevrolet Express 1500 Van, a failing Powertrain Control Module (PCM) is often the culprit. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a faulty PCM can cause a cascade of issues, from a simple check engine light to a vehicle that won’t start at all. This replacement PCM, part number 16263494, is the definitive solution to get your workhorse back on the road, running smoothly and reliably.
The PCM is the brain of your vehicle’s engine and transmission. It controls critical functions like fuel mixture, ignition timing, and transmission shift points. When it fails, performance suffers. Our process eliminates the guesswork and costly dealership visits. We flash this module with the latest official GM software updates, specifically programmed to your vehicle’s unique VIN. This isn’t a generic, one-size-fits-all part; it’s a tailored solution that ensures seamless communication between all your vehicle’s systems right out of the box.
A Technician’s Notebook: The Ghost in the Machine
I remember a 2001 Savana 2500 that came into my shop with a maddeningly intermittent no-start condition. The owner had already replaced the battery, alternator, and starter. It would run fine for days, then refuse to crank. After checking all the usual suspects, I hooked up my high-end scanner to monitor live data. I noticed the PCM wasn’t sending the ‘crank’ signal to the starter relay, even with the key turned. After a few more tests, it was clear: the PCM’s internal driver for that circuit was failing intermittently due to heat soak. We replaced it with a VIN-programmed module like this one, and the van never had the issue again. It’s a classic failure mode for these units after 20+ years of service.
Is Your Vehicle Showing These Symptoms?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is likely the solution you need. This is especially true if you see diagnostic trouble codes (DTCs) like P0601, P0605, or U-series communication codes.
- ✔ Check Engine Light is on with no clear cause.
- ✔ Vehicle fails to start or has intermittent starting issues.
- ✔ Poor fuel economy and engine performance.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine stalling, sputtering, or misfiring.
- ✔ Communication errors with scan tools.
A Straightforward Guide to Your Express 1500 Van PCM Installation
Installing your new PCM is a manageable job for a DIY enthusiast. The most important part is ensuring the battery is disconnected. Since this module comes pre-programmed, no special tools are required for software setup. A basic security relearn procedure may be necessary, which can typically be done without a scan tool.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- Locate the PCM: On most Express/Savana vans, the PCM is located in the engine compartment on the driver’s side, near the rear. On pickups and SUVs, it’s often on the driver’s side fender well or near the battery.
- Disconnect the Harnesses: Carefully unplug the electrical connectors from the old PCM. These connectors have locking tabs that must be released before pulling. Avoid forcing them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware, as you may need it for the new module.
- Install the New PCM: Mount the new module securely onto the bracket and reconnect the wiring harnesses. Ensure they click into place firmly.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn: You may need to perform a simple key-cycle security relearn. A common GM procedure is to turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 30 seconds, and repeat two more times before starting the engine. Instructions will be included.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It is guaranteed to fit a wide range of GM trucks and vans. Please verify your vehicle is on the list below. After purchase, simply provide us with your VIN to ensure perfect programming.
CHEVROLET EXPRESS 1500/2500/3500 VAN (99-02)
GMC 1500/2500/3500 PICKUP (99-00)
GMC SAVANA 1500/2500/3500 VAN (99-02)
CHEVROLET S10 / GMC SONOMA (98-00, 4.3L)
CHEVROLET BLAZER / GMC JIMMY (98-00)
CHEVROLET ASTRO / GMC SAFARI (99-01)
CHEVROLET TAHOE (99-00, Classic Style)
CHEVROLET SUBURBAN 1500/2500 (99)
GMC YUKON / YUKON DENALI (99-00)
CADILLAC ESCALADE (99-00)
OLDSMOBILE BRAVADA (98-00)
GMC ENVOY (98-00)
ISUZU HOMBRE (98-00, 4.3L)
Frequently Asked Questions
Do I need to do anything after installing this PCM?
Because we program the module to your VIN, it’s nearly a plug-and-play installation. In most cases, you will only need to perform a simple security relearn procedure, which involves a few key cycles. We include instructions for this easy process.
How do I provide my VIN number?
After you complete your purchase, you will receive an email with instructions on how to reply with your vehicle’s 17-digit VIN. We cannot ship the module until we receive this information, as the programming is specific to your vehicle.
Is this a reliable, long-term fix?
Absolutely. We use quality components and flash the module with the latest stable software from GM. This addresses many of the original factory software bugs and ensures dependable operation for years to come, restoring your vehicle’s original performance and reliability.
Will this fix my specific problem?
This PCM corrects issues directly caused by a faulty module, such as internal circuit failure (common DTC P0601), processing errors, and driver malfunctions. While it solves a wide range of symptoms, always ensure your vehicle’s wiring and sensors are in good condition. This part is often the final piece of the puzzle after other components have been checked.
What makes your programming service different?
Unlike sending a part to a local shop or the dealership, our process is streamlined for convenience. We handle the complex software flashing before the part even ships, using your VIN to load the exact calibration file your vehicle requires. This saves you time, towing fees, and expensive labor charges.