Restore Your GM Truck’s Performance and Reliability
Is your 1998 or 1999 GM truck or SUV suffering from baffling electrical issues, poor engine performance, or a no-start condition? The Powertrain Control Module (PCM), the electronic brain of your vehicle, is often the culprit. This genuine used GM PCM, part number 9355699, is the definitive solution to get your vehicle running correctly again. It’s not just a replacement part; it’s a fully programmed, plug-and-play solution tailored specifically to your vehicle.
The PCM is responsible for managing critical systems, including fuel injection, ignition timing, transmission shifting, and emissions controls. When it fails, the symptoms can be widespread and confusing, often leading to incorrect diagnoses and expensive, unnecessary repairs. By replacing a faulty module with our pre-programmed unit, you can eliminate the guesswork and restore your vehicle’s original performance and efficiency.
From the Diagnostic Bay
We had a 1998 GMC Jimmy come into the shop that had its owner completely stumped. It would crank but not start, and when it did, it ran rough and threw random communication codes. The owner had already replaced the fuel pump, crank sensor, and ignition coil based on advice from forums. After hooking up our professional scan tool, we noticed the PCM wasn’t communicating consistently. We swapped in a known-good, programmed module, and the Jimmy fired right up and ran perfectly. It’s a classic case where a failing PCM mimics other component failures, costing the owner time and money. Starting with the vehicle’s central computer is often the most direct path to a fix.
The Critical Role of a Programmed 1998 Blazer PCM
For vehicles of this era, simply installing a used computer from another vehicle will not work. Each PCM is programmed with a specific Vehicle Identification Number (VIN) and contains software calibrated for that vehicle’s engine, transmission, and options. Our service eliminates this compatibility problem. When you purchase this module, we require your VIN to flash the unit with the latest GM-certified software for your exact vehicle. This ensures all systems communicate correctly, your engine runs efficiently, and your transmission shifts smoothly, just as it did from the factory.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light is on with various communication or sensor-related trouble codes (e.g., U-codes, P0601-P0606).
- ✔ Engine cranks but refuses to start.
- ✔ Rough idling, stalling, or hesitation during acceleration.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Intermittent loss of power to fuel injectors or spark to ignition coils.
- ✔ Inability to pass an emissions test due to monitor readiness issues.
A Direct-Fit Solution for a Wide Range of GM Vehicles
This PCM, identified by service number 9355699, is a direct replacement for a vast array of popular 1998 and 1999 GM trucks, vans, and SUVs. It is compatible with models such as the Chevrolet Blazer, S10, Tahoe, Suburban, C/K pickups, and Express vans, as well as the GMC Jimmy, Sonoma, Yukon, Sierra, and Savana vans. It also fits the Cadillac Escalade, Oldsmobile Bravada, and Isuzu Hombre from the same period. Please verify that your original module’s part number is listed as a compatible replacement (including 09355699, 16266645, 16250279, 16258815, and 9366810) to ensure a perfect match.
Important Installation Note: After installation, your vehicle may require a security relearn procedure (often called Passlock or Passkey relearn) to allow the engine to start. Additionally, a Crankshaft Variation Relearn (CASE Relearn) may be necessary with a capable scan tool to prevent a P1336 trouble code. These are standard procedures when replacing a PCM on these GM vehicles.
Frequently Asked Questions
Do I need to do anything after I buy this PCM?
Yes. After you complete your purchase, you MUST send us your vehicle’s 17-digit VIN. We cannot ship the module until we have programmed it with your specific vehicle information.
Is this a new part?
No, this is a genuine, used OEM part that has been sourced from a salvaged vehicle. It has been tested for functionality and is ready to be programmed for your vehicle.
Will this fix my transmission shifting problems?
If your shifting issues are caused by a faulty PCM, then yes, this will resolve them. The PCM controls the transmission’s electronic solenoids and shift points. However, mechanical issues within the transmission itself will not be fixed by a PCM replacement.
What is a security relearn procedure?
This is a simple procedure you can do yourself that syncs the new PCM with your vehicle’s anti-theft system. It typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating this sequence three times. Instructions can be easily found online for your specific model.
Does this PCM come with a warranty?
Please refer to the warranty information provided in the listing details. All our programmed modules are tested before shipping to ensure they are fully functional.