Is Your 1998 GM Truck or SUV Running Rough, Stalling, or Refusing to Start?
As a mechanic with over two decades of experience under the hood, I’ve seen countless late-90s GM vehicles sidelined by a failing Powertrain Control Module (PCM). That check engine light that won’t go away, the inexplicable stalling at a stoplight, or the harsh, unpredictable shifting—these are classic signs that the brain of your engine has given up. You’re not just buying a part; you’re buying a solution to get your reliable truck back on the road, and this is the most direct and dependable way to do it.
The Smart Solution: A VIN-Programmed 1998 Blazer S10 PCM
Don’t waste time and money at a dealership. This is a tested, genuine used GM PCM that we program specifically to your vehicle’s Vehicle Identification Number (VIN) before it ever leaves our facility. This isn’t a one-size-fits-all part. We flash it with the latest official GM software updates, ensuring it communicates perfectly with your engine, transmission, and all related systems. This process corrects many of the original software bugs that contributed to drivability issues in the first place.
From My Shop to Your Driveway: A Real-World Scenario
“A customer’s ’98 GMC Jimmy S15 came in on a tow truck last week with a crank-no-start condition. He had already replaced the fuel pump and ignition coil, but nothing worked. After a quick scan, I found no communication with the PCM. We pulled the module and found the classic signs of internal failure on the board. After confirming the part number was 9355699, we installed one of our VIN-programmed units. After performing the security relearn, the truck fired right up and ran smoother than it had in years. This is a fix I’ve performed hundreds of times with consistent success.”
Symptoms of a Failing GM PCM:
- ✔ Persistent Check Engine Light (CEL) with various codes
- ✔ Engine stalling or cutting out while driving
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Complete no-start or crank-no-start condition
- ✔ Poor fuel economy and engine performance
- ✔ Communication errors with diagnostic scan tools
Plug-and-Play Installation: Get Back on the Road Fast
Installing this module is a straightforward job for a DIYer with basic tools. While the exact location varies slightly, on the 1998 Blazer S10/Jimmy S15, you’ll find it in the engine bay on the passenger side. IMPORTANT: After installation, you will need to perform a security relearn procedure (often called a CASE relearn) to sync the new PCM with your vehicle’s anti-theft system. This procedure can typically be done without special tools and instructions are widely available online.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the PCM: Find the existing module in the engine compartment.
- Disconnect: Carefully unclip the wiring harnesses. Avoid breaking the plastic locking tabs, as they can be brittle.
- Unbolt: Remove the bolts or screws holding the PCM bracket in place.
- Install New Module: Seat the replacement PCM in the bracket and secure it.
- Reconnect: Firmly plug in all wiring harnesses until they click into place. Reconnect the battery terminal.
- Perform Security Relearn: Follow the vehicle-specific procedure to sync the module.
Guaranteed Compatibility
This module is a direct replacement for units with service number 9355699. To ensure a perfect match, please verify this number on your vehicle’s original PCM. This unit also replaces the following interchangeable part numbers:
16266645, 16250279, 16258815, 09366810, 9366810
While this part is listed for a 1998 Blazer S10/Jimmy S15, it fits a massive range of GM trucks and vans from 1998-1999, including the C/K Pickup, Suburban, Tahoe, Yukon, Express, Savana, and more. Providing your VIN is the final step to guarantee we deliver a perfectly matched and programmed computer for your exact vehicle.