Is Your 1998 GM Truck or SUV Running Rough?
If your trusty 1998 Chevrolet Blazer, GMC Jimmy, or another compatible GM vehicle is suffering from mysterious performance issues, a faulty Powertrain Control Module (PCM) is a likely culprit. As the central computer, the PCM manages everything from fuel injection and spark timing to transmission shifting and emissions controls. When it begins to fail, it can cause a cascade of frustrating and difficult-to-diagnose problems. This replacement PCM, part number 09366810, is the definitive solution to restore your vehicle’s original performance and reliability.
From the Diagnostic Bay
I once had a 1998 GMC Jimmy S15 come into the shop with a complaint of intermittent stalling at stoplights and a persistent check engine light. The owner had already replaced the fuel pump and filter, thinking it was a fuel delivery issue. After hooking up my scan tool, I noticed erratic data from the throttle position sensor and intermittent communication loss with the module itself. A visual inspection of the wiring showed no damage. We swapped in a known-good, programmed PCM, and the truck ran perfectly. The original module had internal circuit failure, a common issue on these older units. It’s a reminder that what seems like a mechanical problem can often be traced back to the vehicle’s computer.
Common Symptoms of a Failing PCM
A failing engine computer can manifest in numerous ways. If you’re experiencing any of the following, it’s time to consider a replacement:
- ✔ Check Engine Light: An illuminated or flashing Check Engine Light is the most common sign. You may see codes related to sensor circuits, module communication, or internal processor faults.
- ✔ Engine Stalling or Misfiring: The engine may stall unexpectedly, run rough, or misfire as the PCM struggles to properly control fuel and spark.
- ✔ No-Start Condition: In severe cases, a complete PCM failure can prevent the engine from starting at all, as it won’t command the fuel pump or ignition system to operate.
- ✔ Poor Fuel Economy: Incorrect fuel mixture and timing calculations can lead to a noticeable drop in your vehicle’s gas mileage.
- ✔ Harsh or Erratic Shifting: The PCM also controls the automatic transmission. A faulty module can cause delayed, hard, or unpredictable shifting.
- ✔ Failed Emissions Test: If the PCM isn’t operating correctly, your vehicle will not pass a state emissions inspection.
The Direct-Fit Solution: A Pre-Programmed 1998 Blazer S10 PCM
Replacing the PCM on these vehicles used to require a trip to the dealership for expensive programming. Our process eliminates that hassle. We offer a fully tested Powertrain Control Module that is programmed specifically for your vehicle using your Vehicle Identification Number (VIN). This ensures that all factory settings, engine parameters, and security information are correct for your exact make, model, and options. We flash the module with the latest software updates from GM, which can resolve common drivability issues and improve overall performance and efficiency. This is a plug-and-play solution designed to get you back on the road quickly and affordably.
This module is a direct replacement for part numbers 16250279, 09366810, and 09355699 and fits a wide range of 1998-1999 GM trucks, vans, and SUVs, including the Chevrolet Tahoe, GMC Yukon, Suburban, Express/Savana vans, and various C/K pickups. Please verify your part number and check the detailed fitment list to ensure compatibility.
Frequently Asked Questions
Do I need to have this module programmed?
No. We handle all the programming for you before shipment. Simply provide us with your vehicle’s 17-digit VIN during or after checkout, and we will flash the module with the correct factory software for your specific vehicle.
Where is the PCM located on my 1998 Blazer S10 or Jimmy S15?
On the 1998 Blazer/Jimmy/Bravada platform, the PCM is typically located in the engine compartment on the front right (passenger side), often near the coolant overflow tank.
Will I need to perform any additional procedures after installation?
In many cases, it’s a simple plug-and-play installation. However, some GM vehicles of this era may require a security relearn procedure (Passlock) or a Crankshaft Position Sensor (CASE) relearn. These procedures can often be completed without special tools, and instructions are widely available online.
Will this fix my check engine light?
If the check engine light is on due to an internal fault with your original PCM, then yes, this replacement part will resolve the issue and allow the light to be cleared. If the light is on for another reason (e.g., a bad oxygen sensor), that issue will need to be addressed separately.
How do I provide my VIN?
You can add your VIN to the notes section during checkout or send it to us in a message after you place your order. We cannot ship your part until we receive the VIN for programming.