If your Chevy Express or GMC Savana is giving you headaches with a persistent check engine light, erratic shifting, or a frustrating no-start condition, you’ve likely traced the problem to a failing Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen how a faulty PCM can create a cascade of baffling electronic issues. This isn’t just a component; it’s the brain of your vehicle, and when it fails, your work van or truck is dead in the water. This is the reliable, straightforward solution you need.
This is a direct-fit replacement PCM, meticulously programmed with the latest GM software updates specifically for your vehicle. The process is simple: after your purchase, you provide us with your Vehicle Identification Number (VIN), and we handle all the programming before it even leaves our facility. This means no expensive trips to the dealership and no special scan tools required for installation. You get a part that is truly plug-and-play, designed to restore your vehicle’s performance and reliability from the moment you install it. This is the definitive fix for your 1999-2002 Express 3500 Van PCM and many other GM models.
Case Study: A Tricky Diagnosis
I remember a 2001 Express 3500 work van that came into the shop with an intermittent no-start and a random stalling problem that two other shops couldn’t solve. The driver was losing money every day the van was down. We scanned it and found a P0601 code (Internal Control Module Memory Check Sum Error). After verifying the power and ground circuits to the PCM were solid, we knew the module itself was the culprit. Instead of a costly dealer replacement and programming fee, the owner opted for one of our pre-programmed units. The swap took less than 30 minutes in the parking lot. The van fired right up, the code was gone, and it never came back. That’s the power of a reliable, correctly programmed part.
Is Your GM Truck or Van Showing These Signs?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Check Engine Light is illuminated with codes like P0601, P0602, P0604, or P0606.
- ✔ Vehicle refuses to start or has a hard starting condition.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ A significant drop in fuel economy.
- ✔ Engine stalling, sputtering, or misfiring for no apparent reason.
- ✔ Failure to communicate with a diagnostic scan tool.
A Straightforward Guide to Installation
Installing your new 1999-2002 Express 3500 Van PCM is a job most DIYers can handle with basic tools. Follow these steps to get back on the road quickly.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- 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 Connectors: Carefully unclip the wiring harness connectors from the old PCM. These connectors have locking tabs that need to be released before you can pull them off. Avoid forcing them.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you will need it for the new module.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely fasten it.
- Reconnect Everything: Plug the wiring harnesses firmly into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Necessary): On some GM vehicles, you may need to perform a simple security relearn procedure. This usually involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. Your vehicle’s service manual will have the exact procedure.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It is guaranteed to fit the following vehicles:
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
EXPRESS 3500 VAN 01-02 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
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
How do I provide my VIN for programming?
After you complete your purchase, you will receive instructions on how to send us your 17-digit VIN. You can typically reply to your order confirmation email or use a contact form on our website. We cannot ship your module until we receive your VIN.
Is this a new or used part?
This is a high-quality, inspected, and tested replacement component that is guaranteed to meet or exceed original equipment performance. It is programmed with the latest software from GM for optimal function.
Will I need to do anything else after installation?
In most cases, no. The module is programmed to be plug-and-play. However, some GM vehicles with Passlock or other anti-theft systems may require a simple security relearn procedure, which can be done without any special tools. We provide instructions for this common procedure.
How do I know if the PCM is really the problem?
While the symptoms listed are strong indicators, a proper diagnosis is always recommended. Common PCM failure codes (like P0601) are a definitive sign. Also, ensure your battery, alternator, and main ground connections are in good condition, as voltage issues can sometimes mimic PCM failure.
What if my part number is not listed but my vehicle is?
Please contact us with your VIN and original part number. The listed part numbers (16263494, 16265035, 8162634940, etc.) cover a wide range, but there can be variations. We can verify compatibility for you to ensure you get the correct part.