Restore Peak Performance to Your GM Truck or Van
Is your 1998-1999 Suburban, Tahoe, Yukon, or Express van running rough, stalling, or showing a persistent check engine light? These are classic signs of a failing Powertrain Control Module (PCM), the central computer that manages your vehicle’s engine and transmission. A faulty PCM can lead to a cascade of frustrating issues, from poor fuel economy to a complete no-start condition. Don’t let a bad computer keep your reliable GM truck off the road. This genuine, used OEM PCM, part number 9355699, is the definitive solution to get your vehicle running like new again.
Unlike modules from a local salvage yard, this PCM isn’t just a used part—it’s a complete, ready-to-install solution. We take the guesswork and extra expense out of the repair by programming the module specifically for your vehicle using your VIN. This process ensures that the PCM has the latest GM software updates and is perfectly matched to your truck’s specific engine, transmission, and options. This eliminates the need for an expensive trip to the dealership for programming, saving you time and money.
We had a ’99 Tahoe in the shop that was driving the owner crazy. It would randomly stall at stoplights, and the transmission would sometimes shift hard into second gear. There were no consistent trouble codes, just a generic P0300 random misfire that would pop up occasionally. The owner had already replaced the plugs, wires, cap, and rotor. We checked fuel pressure, vacuum lines, and sensor data—everything looked normal. On a hunch, we monitored the PCM’s internal temperature data and noticed it was spiking right before the stall events. We swapped in a known-good, programmed PCM, and the problems vanished instantly. These older PCMs are tough, but heat cycles over 20+ years can cause internal solder joints to fail, leading to exactly these kinds of intermittent, maddening issues.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) on your dashboard.
- ✔ Engine stalling or shutting off unexpectedly while driving.
- ✔ Rough idling, misfires, or hesitation during acceleration.
- ✔ Noticeable decrease in fuel efficiency (MPG).
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Complete no-start condition where the engine cranks but won’t fire up.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Failure to pass state emissions testing.
Why Choose Our Pre-Programmed 1998-1999 Suburban PCM?
This isn’t just a replacement part; it’s a restoration of your vehicle’s core operational integrity. The 1998-1999 Suburban PCM is the brain behind your engine’s performance, and ensuring it functions correctly is critical. Our service provides a fully vetted, tested, and updated module that is a direct-fit replacement for a wide range of GM vehicles from this era. By providing us with your Vehicle Identification Number (VIN) during checkout, you receive a unit that is truly plug-and-play. After installation, a simple security relearn procedure (often called a CASE relearn or Passlock relearn) may be required, which can typically be done in your own driveway without special tools. This simple step syncs the new computer with your vehicle’s anti-theft system.
This module is a direct replacement for multiple part numbers, including 09355699, 16266645, 16250279, 16258815, 09366810, and 9366810. Please verify your part number and consult the extensive fitment list to ensure compatibility with your specific make, model, and engine option. Investing in a properly programmed PCM is the most reliable way to solve complex electronic issues and ensure your truck or van serves you well for years to come.
Frequently Asked Questions
What is the difference between a PCM, ECM, and ECU?
These terms are often used interchangeably. PCM (Powertrain Control Module) is the most accurate term for this part, as it controls both the engine and transmission. ECM (Engine Control Module) and ECU (Electronic Control Unit) are more generic terms. For this application, they all refer to the same computer.
Do I need to get this computer programmed by a dealer?
No. The main benefit of our service is that we program the module for you before it ships. Simply provide your vehicle’s VIN when you order, and it will arrive ready to install with the latest GM software.
Is this a new part?
No, this is a high-quality, tested, and fully functional used OEM (Original Equipment Manufacturer) part sourced from a salvaged vehicle. This ensures perfect fitment and compatibility, which can be an issue with aftermarket units.
What is a security relearn procedure?
After installation, you may need to perform a security relearn to sync the new PCM with your vehicle’s anti-theft system (like GM’s Passlock). This procedure usually involves a sequence of turning the key to the ‘ON’ and ‘OFF’ positions for specific time intervals. Instructions are readily available online for your specific model.
Where is the PCM located on my vehicle?
On most GM trucks and vans from this era (Suburban, Tahoe, C/K Pickups, Express), the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls transmission line pressure and shift points based on data from various sensors. If the PCM is faulty, it can cause hard shifts, delayed shifting, or hunting for gears. However, these symptoms can also be caused by mechanical issues, so a proper diagnosis is always recommended.