Bring Your Workhorse Back to Life
There’s nothing more frustrating than a reliable work van that suddenly isn’t. When your Chevrolet Express 3500 starts acting up—stalling at intersections, hesitating on acceleration, or flashing that dreaded Check Engine Light—it can bring your entire day, or business, to a grinding halt. The Powertrain Control Module (PCM) is the central command center of your vehicle’s engine and transmission. When it fails, it can cause a cascade of confusing and costly problems. This isn’t just a part; it’s the solution to getting your dependable van back on the road and restoring your peace of mind.
Signs Your Engine’s Brain Needs Help
A failing PCM can manifest in various ways, often mimicking other component failures. If you’re experiencing any of the following, it’s a strong indicator that your module is the culprit:
- ✔ Check Engine Light: Often the first warning, with diagnostic trouble codes (DTCs) like P0601 (Internal Control Module Memory Check Sum Error) or other communication-related faults.
- ✔ No-Start or Hard Starting: The engine cranks but refuses to fire up, or takes an unusually long time to start.
- ✔ Erratic Performance: Unexplained stalling, rough idling, sudden jerking, or a noticeable loss of power can all point to a faulty PCM.
- ✔ Poor Fuel Economy: If you’re suddenly making more trips to the gas station, the PCM may not be managing the fuel mixture correctly.
- ✔ Failed Emissions Test: An improperly functioning module can lead to an automatic failure at the testing station.
A Mechanic’s Story: The Intermittent Gremlin
“I had a contractor, Dave, with a ’98 Express work van. He was losing jobs because his van would stall randomly, sometimes in the middle of traffic. He’d replaced the fuel pump, plugs, and wires, but the problem persisted. His scanner couldn’t even reliably communicate with the computer. We plugged in one of our pre-programmed modules, performed the security relearn, and the van fired up perfectly. The ‘gremlin’ was gone. Seeing the relief on his face, knowing he could trust his vehicle again—that’s the real payoff of a solid repair.”
The Perfect Fit: A Pre-Programmed 1998 Express 3500 PCM
Forget the hassle and expense of a dealership visit. We take the guesswork out of the equation. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) after your purchase, and we will flash this module with the latest, most stable GM software specific to your van. It arrives at your door ready for a straightforward installation, ensuring optimal performance and compatibility right out of the box.
Guided Installation to Restore Your Drive
Replacing your PCM is a manageable job for a confident DIYer. Follow these steps for a successful installation.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Old Module: On most 1998 Express vans, the PCM is located in the engine compartment, typically on the driver’s side fender well.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that may need to be gently pried. Once disconnected, unbolt the module from its mounting bracket.
- Install the New PCM: Mount your new, pre-programmed module in place and securely fasten the bolts. Reconnect the electrical harnesses, ensuring they click firmly into place.
- Reconnect the Battery: Attach the negative battery terminal.
- Perform Security Relearn (Crucial Step): Your vehicle’s anti-theft system needs to sync with the new PCM. This is simple:
- a. Turn the key to the “ON” position (do not start the engine).
- b. Observe the “Security” or “Theft” light on the dash. It will be on or flashing.
- c. Wait approximately 10-12 minutes, or until the light turns off.
- d. Turn the key to “OFF” for 10 seconds.
- e. Repeat steps a-d two more times for a total of three cycles.
- f. The vehicle should now start and run normally.
Tailored Fit for Your GM Truck or Van
This module is a direct replacement for part number 16250279 and is compatible with a wide range of GM vehicles from that era. Please verify your part number and check the list below to ensure a perfect match.
- Cadillac Escalade (1999)
- Chevrolet/GMC Pickups (1500/2500/3500) (1998-1999) with gasoline engines
- Chevrolet/GMC Suburban (1500/2500) (1998-1999) with gasoline engines
- Chevrolet Tahoe / GMC Yukon (1998-1999)
- Chevrolet Astro / GMC Safari (1998-1999)
- Chevrolet Express / GMC Savana (1500/2500/3500) (1998) with gasoline engines
- Chevrolet S10 / GMC Sonoma / Jimmy S15 (1998)
- Oldsmobile Bravada (1998)
- GMC Envoy (1998)
- Isuzu Hombre (1998)
Pro Tip: Check Your Grounds
Before installing your new PCM, take a moment to inspect and clean the main engine and chassis ground connections. A poor ground can cause erratic voltage, which is a common reason for original PCM failure. A few minutes with a wire brush can save you from future headaches and protect your investment.
Frequently Asked Questions
Do I need to do anything after installing this PCM?
Yes. After the physical installation, you must perform the vehicle’s security relearn procedure, also known as the Passlock or Passkey relearn. We provide simple, step-by-step instructions for this process, which takes about 30 minutes and requires no special tools.
How do I provide my VIN for programming?
After you complete your purchase, you can send us a message with your 17-digit VIN. We cannot ship your part until we have this information, as the programming is essential for the module to work with your specific vehicle.
Will this fix my specific problem?
This PCM is a direct solution for a failed module. While it resolves a wide range of performance and drivability issues, it’s always best to have a proper diagnosis performed to rule out other potential causes like faulty sensors or wiring.
Is this a used part?
This is a high-quality, professionally inspected and prepared component. Each module undergoes rigorous testing to ensure it meets or exceeds original equipment standards for performance and reliability before being programmed for your vehicle.
What if my original part number is different?
This module is compatible with several part numbers, including 09366810 and 09355699. As long as your vehicle is on the compatibility list and your original module is one of these numbers, this part will work perfectly.