Is your 1998 Chevy Blazer S10 or GMC Jimmy S15 running rough, stalling, or refusing to start? Are you battling persistent check engine lights that won’t go away? These are classic signs of a failing Powertrain Control Module (PCM), the central computer responsible for managing your vehicle’s engine and transmission performance. A faulty PCM can lead to a cascade of frustrating issues, from poor fuel economy and failed emissions tests to unpredictable shifting and a complete no-start condition. Don’t let a bad computer keep your reliable truck off the road. This direct-fit replacement PCM is the definitive solution to restore your vehicle’s original performance and reliability.
This module, part number 16250279, is not just a replacement part; it’s a complete, ready-to-install solution. We take the guesswork and extra expense out of the repair process. Upon purchase, simply provide us with your vehicle’s Vehicle Identification Number (VIN). Our technicians will then program the module with the latest, most up-to-date software directly from General Motors, ensuring it is perfectly matched to your vehicle’s specific configuration. This critical programming step ensures all systems communicate correctly, from the fuel injectors and ignition timing to the transmission shift points. The result is a seamless, plug-and-play installation that gets you back on the road quickly and confidently.
From the Diagnostic Bay
We had a ’98 Jimmy S15 come into the shop with a complaint of intermittent stalling and a check engine light for an oxygen sensor circuit. The owner had already replaced the O2 sensor twice with no luck. After hooking up our diagnostic scanner, we noticed the sensor voltage was completely flatlined, which is unusual. Instead of just throwing another sensor at it, we checked the wiring and found it was perfect. This pointed us to the PCM itself. The driver circuit inside the module responsible for reading that specific sensor had failed. We installed one of our pre-programmed PCMs, performed the quick CASE relearn, and the truck ran perfectly. The O2 sensor codes vanished, and the stalling issue was gone. It’s a great reminder that sometimes the root cause lies with the computer, not the component it’s monitoring.
Diagnosing Your 1998 Blazer S10 PCM
A failing powertrain computer can manifest in numerous ways, often mimicking other component failures. If you’re experiencing several of the following symptoms, it’s highly likely that your 1998 Blazer S10 PCM is the culprit. Replacing it with our correctly programmed unit is the most effective way to solve these complex electronic issues and ensure your engine operates at peak efficiency.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light: The light is on, and you may have codes related to sensor circuits, module communication errors (U-codes), or random misfires.
- ✔ Engine Stalling: The engine may stall unexpectedly while driving or when coming to a stop.
- ✔ Rough Idle or Misfiring: The engine runs poorly, shakes, or feels down on power due to incorrect fuel and spark control.
- ✔ No-Start Condition: The engine cranks but will not start because the PCM is not firing the ignition coils or fuel injectors.
- ✔ Poor Fuel Economy: A significant, unexplained drop in gas mileage can be caused by the PCM failing to manage the engine’s fuel mixture correctly.
- ✔ Erratic Automatic Transmission Shifting: Harsh shifts, delayed engagement, or getting stuck in a single gear can be caused by the PCM, which also controls transmission functions.
- ✔ Failed Emissions Test: Inability to pass a smog check is a common indicator of a malfunctioning engine computer.
This module is a direct replacement for part numbers 16250279, 09366810, and 09355699. It is compatible with a wide range of 1998 and 1999 GM trucks, vans, and SUVs, including the Chevrolet S10, GMC Sonoma, Oldsmobile Bravada, and many full-size trucks and vans. By providing your VIN, you guarantee that the software loaded onto the module is the correct one for your vehicle’s engine, transmission, and emissions equipment. This eliminates compatibility issues and ensures a smooth repair.
Frequently Asked Questions
What is a PCM and what does it do?
The Powertrain Control Module (PCM) is the main computer in your 1998 Blazer/Jimmy. It controls all aspects of the engine and transmission, including fuel mixture, ignition timing, idle speed, and transmission shifting, to ensure optimal performance and emissions.
Is this module difficult to install?
No, the physical installation is straightforward for someone with basic mechanical skills. It typically involves disconnecting the battery, unplugging the electrical connectors from the old module, unbolting it, and then bolting the new one in its place. The key is that our module arrives pre-programmed, saving you a trip to the dealership.
Do I need to perform any procedures after installation?
Yes, on most of these GM vehicles, you will need to perform a Crankshaft Variation Relearn procedure, also known as a CASE relearn. This can be done with a compatible high-level scan tool and is necessary to prevent a P1336 trouble code. Many local repair shops can perform this for you if you don’t have the tool.
How do I provide my VIN for programming?
After you complete your purchase, you will receive instructions on how to send us your 17-digit Vehicle Identification Number (VIN). We cannot ship your part until we receive this information, as the programming is specific to your exact vehicle.
Will this part fit other vehicles besides the 1998 Blazer S10?
Absolutely. This PCM, identified by part number 16250279, fits a wide variety of 1998-1999 GM trucks, SUVs, and vans, 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 specific model.