Restore Peak Performance to Your GM Workhorse
As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Powertrain Control Module (PCM) can bring a reliable work van to a grinding halt. If your 1999-2002 Express 2500 Van is experiencing baffling issues like stalling, erratic shifting, or a persistent check engine light, the solution is often found in the vehicle’s electronic brain. This isn’t just a replacement part; it’s a direct-fit solution to restore your vehicle’s core functionality and get you back on the road with confidence.
This PCM, identified by part number 16263494, arrives at your door fully programmed with the latest GM software updates. We handle the critical flashing process for you—all we need is your vehicle’s VIN at checkout. This eliminates the need for expensive dealership programming or specialized scan tools, making it an ideal fix for both professional mechanics and dedicated DIYers. By replacing your faulty module, you’re not just clearing codes; you’re addressing the root cause of poor performance and potential no-start conditions that can cost you time and money.
From the Diagnostic Bay: The Work Van That Wouldn’t Start
A local contractor brought in his Express 2500, a van that was his mobile office. The complaint was intermittent no-starts and random stalling. He’d already replaced the battery and alternator. After connecting my scanner, I saw no communication with the PCM. A quick wiggle test of the harness connectors at the module caused the fuel pump relay to click on and off. While sometimes it’s a bad connection, in this case, the internal board of the PCM had developed micro-fractures from years of heat and vibration. Installing a pre-programmed 1999-2002 Express 2500 Van PCM solved all the issues instantly. It’s a classic failure mode for these hard-working vehicles, and a new module is the definitive fix.
Common Signs of a Failing PCM
A failing computer can mimic many other problems. Before you start replacing sensors and pumps, see if your vehicle is showing these classic symptoms of a bad PCM. In my shop, these are the tell-tale signs I look for:
- ✔ Check Engine Light is on with communication codes (like U0100) or internal processor fault codes (P0601, P0602, P0606).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling or rough idling, especially after the engine warms up.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Noticeable decrease in fuel economy.
- ✔ The vehicle fails to pass an emissions test.
- ✔ Other modules on the vehicle cannot communicate with the PCM.
A Straightforward Guide to PCM Installation
Replacing the PCM in your GM van or truck is a manageable job for anyone with basic tools. This module for the 1999-2002 Express 2500 Van PCM is designed for a direct swap. Follow these steps for a smooth installation:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes for the system capacitors to discharge.
- Locate the Old 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 typically on the driver’s side front, near the battery or airbox.
- Disconnect the Connectors: Carefully unclip the wiring harness connectors. These connectors have locking tabs that need to be released. Avoid pulling on the wires themselves.
- Remove the Module: Unbolt the old PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten it.
- Reconnect Everything: Plug the wiring harnesses back into the new module until they click firmly into place. Reconnect the negative battery terminal.
- Security Relearn (If Necessary): For many of these GM vehicles, 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 two more times. This allows the new PCM to sync with your vehicle’s anti-theft system.
Verified Vehicle Compatibility
This module is a direct replacement for part number 16263494 and is also compatible with 16265035, 8162634940, 218-11787, and 21811787. Please verify your vehicle is on the list below. Providing your VIN during checkout ensures we send you a perfectly matched and updated unit.
CHEVROLET 2500 PICKUP 00 Electronic Control Module; gasoline (LH front engine compartment)
EXPRESS 1500 VAN 00 Electronic Control Module; (LH rear engine compartment)
EXPRESS 2500 VAN 00 Electronic Control Module; (LH rear engine compartment), gasoline
EXPRESS 3500 VAN 00 Electronic Control Module; (LH rear engine compartment), gasoline
SAVANA 1500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), ID 16263494
ASTRO 00-01 Electronic Control Module; (LH front by battery), ID 16263494
GMC 3500 PICKUP 00 Electronic Control Module; gasoline (LH front engine compartment)
EXPRESS 2500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
S10/S15/SONOMA 99-00 Electronic Control Module; (RH front engine compartment), 4.3L
SAVANA 1500 VAN 00 Electronic Control Module; (LH rear engine compartment)
ASTRO 99 Electronic Control Module; (LH front by battery), (4.3L), ID 16263494
ISUZU HOMBRE 99-00 Electronic Control Module; (RH front engine compartment), 4.3L (6 cylinder)
SAFARI (GMC) 99-01 Electronic Control Module; (LH front by battery), ID 16263494
SAVANA 3500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
EXPRESS 1500 VAN 99 Electronic Control Module; (LH rear engine compartment), ID 16263494
GMC 1500 PICKUP 99 Electronic Control Module; 5.0L, (LH engine compartment), ID 16263494
BLAZER S10/JIMMY S15 98 Electronic Control Module; (RH front engine compartment), w/build date opt ZN4
GMC 1500 PICKUP 99 Electronic Control Module; 5.7L, (LH engine compartment), ID 16263494
SAVANA 3500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
SAVANA 3500 VAN 00 Electronic Control Module; (LH rear engine compartment), gasoline
TAHOE 00 Electronic Control Module; Classic style (LH front engine compartment)
YUKON 99 Electronic Control Module; (LH engine compartment), ID 16263494
ESCALADE 99 Electronic Control Module; (LH front engine compartment), ID 16263494
ESCALADE 00 Electronic Control Module; (LH front under battery)
EXPRESS 2500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
S10/S15/SONOMA 98 Electronic Control Module; 6-262 (4.3L), w/build date opt ZN4
YUKON 00 Electronic Control Module; (LH front under battery), Denali
BRAVADA 98 Electronic Control Module; (6-262, 4.3L), w/build date opt ZN4
CHEVROLET 3500 PICKUP 00 Electronic Control Module; gasoline (LH front engine compartment)
ENVOY 99-00 Electronic Control Module; (RH front engine compartment)
EXPRESS 1500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), ID 16263494
EXPRESS 3500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
GMC 3500 PICKUP 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
ISUZU HOMBRE 98 Electronic Control Module; 4.3L (6 cylinder), w/extended build date opt ZN4
SIERRA 1500 PICKUP 99-00 Electronic Control Module; (LH front under battery), 6 cylinder
SAVANA 2500 VAN 00 Electronic Control Module; (LH rear engine compartment), gasoline
SUBURBAN 1500 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
CHEVROLET 1500 PICKUP 99 Electronic Control Module; 5.7L, (LH engine compartment), ID 16263494
EXPRESS 3500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
GMC 2500 PICKUP 00 Electronic Control Module; gasoline (LH front engine compartment)
SILVERADO 1500 PICKUP 99-00 Electronic Control Module; (LH front under battery), 6 cylinder
SUBURBAN 2500 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
BLAZER S10/JIMMY S15 99-00 Electronic Control Module; (RH front engine compartment)
CHEVROLET 3500 PICKUP 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
SAVANA 1500 VAN 99 Electronic Control Module; (LH rear engine compartment), ID 16263494
TAHOE 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
BRAVADA 99-00 Electronic Control Module; (RH front engine compartment)
CHEVROLET 1500 PICKUP 99 Electronic Control Module; 5.0L, (LH engine compartment), ID 16263494
SAVANA 2500 VAN 99 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
SAVANA 2500 VAN 01-02 Electronic Control Module; (LH rear engine compartment), gasoline, ID 16263494
ENVOY 98 Electronic Control Module; (RH front engine compartment), w/build date opt ZN4
GMC 2500 PICKUP 99 Electronic Control Module; gasoline (LH front engine compartment), ID 16263494
Frequently Asked Questions
What exactly is VIN programming?
VIN programming is the process of loading your vehicle’s specific Vehicle Identification Number (VIN) and factory software into the PCM. This ensures the module communicates correctly with your engine, transmission, and other systems, just like the original part from the factory.
Is this part ready to install out of the box?
Yes! Once we program the module with your VIN, it is ready for installation. In most cases, it’s a plug-and-play process, though some vehicles may require a simple key-cycle security relearn procedure as outlined in our installation guide.
Will this fix my specific problem?
This PCM is the solution for issues directly caused by a faulty module, such as internal processor errors, communication faults, and driver circuit failures. While it resolves many common symptoms, we always recommend proper vehicle diagnostics to confirm the PCM is the point of failure.
Do I need to send my old PCM (core) back?
No core charge or return is required for this purchase. You can recycle your old module locally.
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot ship your order until we receive and validate your VIN.