Is Your GM Truck or SUV Running Rough?
If your 1998 Chevrolet Blazer, GMC Jimmy, or another compatible GM vehicle is suffering from mysterious engine problems, a failing Powertrain Control Module (PCM) is a very likely culprit. The PCM is the central computer of your vehicle, responsible for managing everything from fuel injection and spark timing to transmission shifting and emissions controls. When it starts to fail, it can create a cascade of frustrating and difficult-to-diagnose issues, leaving you stranded or dealing with poor performance.
From the Diagnostic Bay
I once had a 1999 Tahoe come into the shop with an intermittent no-start condition. The owner had already replaced the battery, alternator, and starter to no avail. He was frustrated and had spent a lot of money on parts that didn’t fix the issue. After hooking up the scanner, I noticed erratic data from the PCM and a few communication error codes. Instead of throwing more parts at it, we tested the PCM’s power and ground circuits, which were solid. The diagnosis pointed to an internal failure in the module itself. We installed a VIN-programmed PCM just like this one, performed the security relearn, and the truck fired up instantly. It’s a classic case where diagnosing the core problem—the vehicle’s brain—saved the customer from further unnecessary repairs and expense.
Symptoms of a Failing Powertrain Control Module
A faulty PCM can manifest in many ways. If you’re experiencing any of the following, it might be time to replace your engine computer. This genuine used 1998 Blazer S10 PCM is the reliable solution you need.
- ✔ Persistent Check Engine Light with various trouble codes.
- ✔ Engine stalling, stuttering, or misfiring for no apparent reason.
- ✔ A sudden and significant drop in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The vehicle cranks but refuses to start (no-start condition).
- ✔ Failure to communicate with diagnostic scan tools.
- ✔ Inconsistent performance that gets worse as the engine warms up.
The Right Part, Programmed for Your Vehicle
Don’t settle for a generic, unprogrammed module that will cause more problems than it solves. This is a genuine, used GM PCM, part number 16266645 (interchangeable with 09355699 and others listed), sourced from a salvaged vehicle and thoroughly inspected. The critical difference is our professional programming service. Before we ship the part, our technicians will flash it with the latest official GM software calibration specifically for your vehicle. All we need is your Vehicle Identification Number (VIN) at checkout.
This VIN-specific programming ensures that the module communicates perfectly with your vehicle’s engine, transmission, and security systems, making for a straightforward installation. While this is a direct-fit replacement, please be aware that on most GM vehicles of this era, you will need to perform a security relearn procedure (often called Passlock or Passkey relearn) after installation. This is a simple process that pairs the new computer to your vehicle’s anti-theft system and typically does not require special tools.
Why a VIN-Programmed 1998 Blazer S10 PCM is Essential
Your vehicle’s VIN contains specific information about its engine, transmission, emissions equipment, and other factory options. Programming the PCM with this information is not optional—it’s mandatory for proper function. An unprogrammed module will not allow the vehicle to start or run correctly. By providing us with your VIN, you receive a part that is ready to be installed and integrated into your vehicle’s systems, restoring its original performance and reliability.
Frequently Asked Questions
What is a PCM and what does it do?
The Powertrain Control Module (PCM), also known as the Engine Control Module (ECM), is your vehicle’s main computer. It controls all aspects of engine and transmission function to ensure optimal performance, fuel efficiency, and emissions.
Do I need to do anything after installing this PCM?
Yes. After installation, you will most likely need to perform a security relearn procedure. This process syncs the new PCM with your vehicle’s anti-theft system. It’s a simple procedure that can usually be done without special tools and instructions are widely available online for your specific model.
How do I provide my VIN?
You can add your 17-digit VIN in the notes section during checkout or send it to us in a message after your purchase. We cannot program and ship your module without it. Your VIN is typically found on your driver’s side dashboard (visible through the windshield) or on the driver’s side door jamb sticker.
Is this a new part?
No, this is a high-quality, tested, and fully functional used part sourced from a salvaged vehicle. This allows us to provide a reliable, factory component at a significant cost saving over a new part from the dealer.
Will this fit vehicles other than a 1998 Blazer?
Absolutely. This PCM, identified by service number 09355699 or 16266645, fits a wide range of 1998-1999 GM trucks, vans, and SUVs including the Tahoe, Suburban, C/K Pickups, and Express/Savana vans. Please check the detailed fitment list on this page to confirm compatibility with your exact model.