Restore Your Van’s Heartbeat and Your Peace of Mind
Is your trusty 1998 Express 3500 letting you down? Erratic shifting, a stubborn check engine light, or a frustrating no-start condition can sideline your workhorse, costing you time, money, and confidence. The Powertrain Control Module (PCM) is the brain of your vehicle’s operation, and when it falters, the symptoms can be maddening. This isn’t just a part; it’s the solution to getting your reliable van back on the road, performing as it should. We provide a fully programmed PCM, flashed with the latest GM software specifically for your vehicle’s VIN, ensuring a seamless and effective repair.
From the Trenches: A Diagnostic Tale
I once had a customer with a ’99 Suburban—same platform as your van—that had a persistent, random misfire code (P0300) that no one could solve. He’d replaced plugs, wires, the coil, and even the fuel injectors. He was at his wit’s end. When he brought it to me, I scoped the injector driver circuits directly at the PCM connector. Sure enough, the signal for cylinder 3 would occasionally drop out. The problem wasn’t in the engine bay; it was a failing driver inside the original computer. A new, properly programmed PCM like this one solved the issue in under an hour. It’s a powerful reminder that the PCM is the central command, and its health is critical for everything else to function correctly.
Warning Signs Your PCM Needs Attention
A failing computer can manifest in numerous ways. If you’re experiencing any of the following, a faulty PCM is a likely culprit:
- ✔ Check Engine Light: Especially for internal module codes like P0601, P0603, P0605, or P0606.
- ✔ Poor Performance: Noticeable loss of power, hesitation during acceleration, or rough idling.
- ✔ Reduced Fuel Economy: The engine isn’t receiving the correct parameters for fuel delivery, causing it to run rich or lean.
- ✔ Transmission Problems: Harsh or delayed shifting, or getting stuck in one gear (limp mode).
- ✔ Intermittent Stalling or No-Start: The PCM may be failing to control the ignition or fuel systems properly.
- ✔ Communication Errors: Your scan tool is unable to connect with the vehicle’s computer.
Why Choose Our Pre-Flashed 1998 Express 3500 PCM?
Forget the hassle and expense of a dealership visit. The biggest hurdle in replacing a PCM is the programming. We take care of that for you. By flashing this module with the newest GM updates and coding it directly to your vehicle’s unique VIN, we deliver a component that is truly plug-and-play. This process ensures all factory settings, anti-theft systems (if applicable), and powertrain parameters are perfectly matched to your van, restoring original performance and reliability from the moment you install it.
Guided Installation to Restore Your Confidence
You don’t need to be a master mechanic to complete this job. Follow these simple steps to get your vehicle back in top shape.
- Safety First: Always disconnect the negative terminal of your vehicle’s battery and wait at least 10 minutes to allow the system to fully discharge.
- Locate the Old PCM: On most GM vans and trucks of this era, the PCM is located in the engine compartment, typically on the driver’s side fender or near the battery.
- Disconnect the Harnesses: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Inspect the connectors for any corrosion or damaged pins.
- Swap the Modules: Unbolt the old PCM from its mounting bracket and set it aside. Mount the new module securely in its place.
- Reconnect and Secure: Plug the electrical harnesses firmly into your new PCM. You should hear a click as they lock into place. Reconnect the negative battery terminal.
- Final Steps: In some cases, a security or crank-position sensor relearn procedure may be needed. This can often be done without special tools. We include simple instructions for any required procedures with your order.
Tailored Fit for Your Ride
This module is a direct replacement for service number 09366810 and is also compatible with 16250279 and 09355699. It fits a wide range of GM vehicles, ensuring a perfect match for your application. Please verify your part number or consult the list below:
- 1998-1999 Chevrolet & GMC C/K 1500/2500/3500 Pickups (Gasoline)
- 1998 Chevrolet Express & GMC Savana 1500/2500/3500 Vans (Gasoline)
- 1998-1999 Chevrolet Tahoe & GMC Yukon (Gasoline)
- 1998-1999 Chevrolet & GMC Suburban (Gasoline)
- 1999 Cadillac Escalade
- 1998-1999 Chevrolet Astro & GMC Safari
- 1998 Chevrolet S10 Blazer, GMC S15 Jimmy, Oldsmobile Bravada, GMC Sonoma, Isuzu Hombre (4.3L V6)
Frequently Asked Questions
How do I provide my VIN number?
After you complete your purchase, simply reply to your order confirmation email with your 17-digit Vehicle Identification Number (VIN). You can also add it to the ‘notes’ section during checkout. We cannot ship your part until we receive the VIN.
Is any additional programming required after installation?
No! This 1998 Express 3500 PCM arrives fully programmed to your VIN. In most cases, it is a simple plug-and-play installation. We will include instructions for a security relearn procedure if it is required for your specific vehicle, which can be done without special tools.
What if my original part number is slightly different?
This module replaces several part numbers, including 16250279 and 09355699. As long as your vehicle is on the compatibility list and you provide your VIN, we will ensure the programming is a perfect match for your application.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls the transmission’s shift points and line pressure. If your transmission issues are electronic in nature (caused by the computer), this part is the correct solution. It will not fix internal mechanical failures within the transmission.
Is this a used part?
This is a professionally inspected and verified OEM component that has been tested and flashed with the latest vehicle-specific software. It meets or exceeds original factory performance standards, providing a reliable and cost-effective solution.