Is your 1998 or 1999 GM truck, van, or SUV running rough, stalling, or showing a persistent check engine light? These are classic signs of a failing Powertrain Control Module (PCM). The PCM is the brain of your vehicle, controlling everything from fuel mixture and ignition timing to transmission shifting. When it fails, it can cause a cascade of frustrating and hard-to-diagnose issues. This isn’t just an inconvenience; a faulty PCM can lead to poor fuel economy, failed emissions tests, and even leave you stranded. Don’t keep throwing parts at the problem. Get the direct-fit, reliable solution with our VIN-programmed engine computer.
Diagnosing Your 1998-1999 GM Truck PCM
A failing engine computer can mimic many other problems, making diagnosis tricky. If you’ve already checked your sensors and wiring, the module itself is the likely culprit. This replacement PCM is the definitive solution for restoring your vehicle’s original performance and reliability. We take the guesswork out of the repair by programming the unit specifically for your vehicle using your VIN, ensuring a seamless installation process.
From the Diagnostic Bay
We had a 1999 Chevy Suburban come in that the owner had spent a fortune on. It had a random misfire code (P0300) that just wouldn’t go away. He had replaced the plugs, wires, cap, rotor, and even the fuel spider injector assembly. The truck ran okay for a bit, then the light would come back. After hooking up our professional scan tool and monitoring the live data, we noticed the ignition control signals from the PCM were erratic. We swapped in one of our pre-programmed modules, performed the security relearn, and the truck ran perfectly. The customer was thrilled to finally have a reliable vehicle again. It’s a common story: sometimes the simplest-looking component is the root of the most complex problems.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light is on with various, often inconsistent, trouble codes.
- ✔ Engine stalling or shutting off unexpectedly while driving.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Failure to pass state emissions inspection.
- ✔ Communication errors with diagnostic scan tools.
The Plug-and-Play Solution
Why choose our PCM? Because we handle the most critical step for you. Dealerships and many repair shops will charge you a significant fee to program a replacement computer. We flash this used, fully tested module with the latest official GM software updates tailored to your vehicle’s VIN before it ever leaves our facility. This means that for most vehicles, the installation is straightforward. Simply disconnect the battery, swap the modules, reconnect the battery, and perform the security relearn procedure. You’ll restore factory performance without the high cost and hassle of a dealership visit.
This unit is a genuine used part sourced from a salvaged vehicle, ensuring OEM quality and fitment. It is a direct replacement for multiple part numbers, including 09355699, 16266645, 16250279, 16258815, and 09366810. Please verify your part number and consult the extensive fitment list to ensure compatibility with your specific make, model, and engine.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential because it allows us to program the PCM with the exact software calibration your vehicle requires. This includes information about the engine, transmission, emissions equipment, and other factory options. Without the correct VIN-specific program, the module will not function correctly.
Is this a new part?
No, this is a high-quality, tested used PCM that has been sourced from a salvaged vehicle. Each unit is inspected and verified to be fully functional before being programmed and shipped. This provides an affordable and reliable alternative to a costly new module.
Will I need to do anything after installing this PCM?
Yes, after installing the module, you will need to perform a security relearn procedure, often called a “CASE Relearn” or “Passlock Relearn.” This syncs the new computer with your vehicle’s anti-theft system. The procedure is simple and can typically be done without special tools. Instructions can be easily found online for your specific model.
What is the difference between a PCM, ECM, and ECU?
The terms are often used interchangeably. ECM (Engine Control Module) typically controls only engine functions. A PCM (Powertrain Control Module) is more integrated and controls both the engine and the transmission. For most GM vehicles of this era, the correct term is PCM. ECU (Electronic Control Unit) is a more generic term for any computer in a vehicle.
How do I find my VIN?
Your 17-digit VIN can be found on your vehicle’s registration, insurance card, or on the vehicle itself. Look for a small metal plate on the driver’s side of the dashboard, visible through the windshield, or on the sticker inside the driver’s side door jamb.