Is your late-90s GM truck, van, or SUV running poorly? Experiencing frustrating issues like stalling, a no-start condition, or a persistent check engine light? The Powertrain Control Module (PCM), the central computer for your engine and transmission, is often the culprit. This vital component manages everything from fuel delivery and ignition timing to transmission shift points. When it fails, it can cause a cascade of problems that are difficult to diagnose. This listing offers a direct, reliable solution: a genuine used GM PCM, part number 09355699, professionally programmed to your vehicle’s specific VIN.
From the Diagnostic Bay
We had a 1999 Chevy Tahoe come into the shop that was driving its owner crazy. It would randomly stall at stoplights and sometimes refuse to start for 10-15 minutes, then fire right up as if nothing was wrong. The owner had already replaced the fuel pump and ignition control module with no luck. After hooking up our professional scan tool, we noticed intermittent communication loss with the PCM. A detailed wiring check showed no faults. We suspected an internal failure in the module itself, a common issue on these GMT400 platforms due to heat and vibration. We installed one of these VIN-programmed PCMs, performed the quick security relearn procedure, and the Tahoe ran perfectly. The customer called a week later to say the ghost was gone for good. It’s a classic case where shotgunning parts doesn’t work, but replacing the core problem does.
Common Symptoms of a Faulty 1998-1999 GM PCM
A failing engine computer can manifest in numerous ways, often mimicking other sensor or component failures. If your vehicle is exhibiting several of the following symptoms, a faulty PCM is a likely cause. This module is the solution for restoring proper function and communication between your vehicle’s critical systems.
Key Indicators of PCM Failure
- ✔ Check Engine Light: Your check engine light is illuminated with PCM-specific codes, such as P0601, P0604, or P0606, indicating internal module errors.
- ✔ No-Start or Intermittent Stalling: The engine cranks but won’t start, or it stalls unexpectedly while driving or at idle.
- ✔ Poor Engine Performance: You may experience reduced power, hesitation on acceleration, rough idling, or a significant decrease in fuel economy.
- ✔ Harsh or Erratic Shifting: The transmission may shift hard, slip between gears, or get stuck in one gear (limp mode).
- ✔ Communication Errors: A scan tool cannot communicate with the PCM, making diagnosis of other issues impossible.
- ✔ Failed Emissions Test: The vehicle cannot pass an emissions test due to readiness monitors not setting or persistent fault codes.
The VIN Programming Advantage
You cannot simply take a PCM from another vehicle and install it in yours. The module is programmed with specific software and calibrations for the original vehicle’s engine size, transmission type, emissions equipment, and other options. Our service eliminates the guesswork and the need for an expensive trip to the dealership. Simply provide us with your 17-digit VIN during checkout, and our technicians will flash this module with the latest GM-certified software for your exact vehicle. This ensures it works seamlessly with your existing components right out of the box after a simple security relearn.
This 1998-1999 GM PCM is a direct replacement for multiple part numbers, ensuring wide compatibility. Please verify that your original module carries one of the following numbers:
- 09355699
- 16266645
- 9355699
- 16250279
- 16258815
- 09366810
- 9366810
Frequently Asked Questions
Do I need to program this computer?
No. This PCM comes fully programmed to your vehicle’s specific VIN before it is shipped. You just need to provide your VIN to us after purchase.
Is this part difficult to install?
Physically, the installation is straightforward. It typically involves disconnecting the battery, unplugging the electrical connectors, and unbolting the old module. However, after installation, you will likely need to perform a security relearn procedure (such as a Passlock or CASE relearn) which can usually be done without special tools. Instructions can be readily found online for your specific model.
Where is the PCM located on my vehicle?
On most 1998-1999 GM trucks, vans, and SUVs, the PCM is located in the engine compartment, often on the driver’s side inner fender, near the battery, or on the firewall.
How do I find my vehicle’s VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on a metal plate on the driver’s side of the dashboard (visible through the windshield), on the driver’s side door jamb sticker, and on your vehicle’s registration and insurance documents.
Is this a new part?
This is a high-quality, tested, used OEM part sourced from a salvaged vehicle. It has been inspected for integrity and is ready for programming and installation.