Is your 1998 or 1999 GMC 2500 Pickup running rough, stalling, or refusing to start? Are you battling a persistent Check Engine Light with codes pointing to an internal computer failure? A faulty Powertrain Control Module (PCM) is often the culprit behind these frustrating and hard-to-diagnose issues. The PCM is the central brain of your truck’s engine and transmission, and when it fails, it can cause a wide range of performance problems. This listing offers a direct, reliable solution: a genuine, used OEM PCM, part number 16258815, professionally programmed specifically for your vehicle.
We take the guesswork and hassle out of the replacement process. Simply provide us with your vehicle’s 17-digit VIN (Vehicle Identification Number) after your purchase, and our technicians will flash the module with the latest, most up-to-date software directly from GM. This ensures perfect compatibility with your truck’s specific engine, transmission, and options. Your replacement PCM will arrive ready for installation, saving you a costly trip to the dealership for programming.
From the Diagnostic Bay
We had a customer bring in a ’99 Chevy Suburban with a classic complaint: intermittent stalling at stoplights and a random misfire that no one could pinpoint. He had already replaced the spark plugs, wires, cap, rotor, and even the fuel pump, spending hundreds of dollars with no improvement. After hooking up our scanner, we noticed erratic sensor readings that didn’t make sense. Instead of chasing more parts, we focused on the PCM. We swapped in a known-good, programmed module, and the truck immediately ran like new. The original PCM had internal faults that were corrupting sensor data, sending the owner on a wild goose chase. This is a perfect example of how a failing computer can mimic many other mechanical issues.
Diagnosing a Failing 1998-1999 GMC 2500 PCM
The PCM is a complex electronic component, and its failure can manifest in numerous ways. If your truck is experiencing any of the following symptoms, a faulty engine computer could be to blame. This module is the correct solution for these common issues.
- ✔ Check Engine Light: The light is on, and you may have codes related to internal processor failure, sensor circuits, or communication errors (U-codes).
- ✔ No-Start or Hard-Start: The engine cranks but won’t start, or takes an excessively long time to fire up, especially when warm.
- ✔ Engine Stalling: The engine randomly shuts off while driving or idling at a stop.
- ✔ Poor Performance & Fuel Economy: You may notice a significant drop in power, hesitation during acceleration, and a noticeable decrease in miles per gallon.
- ✔ Rough or Unstable Idle: The engine idles erratically, surging up and down or feeling like it’s about to stall.
- ✔ Harsh or Incorrect Shifting: The automatic transmission may shift erratically, slam into gear, or fail to shift at the correct points.
- ✔ Communication Issues: A diagnostic scan tool may be unable to communicate with the PCM.
Plug-and-Play Solution with VIN Programming
This isn’t just a used part pulled from a yard. It’s a complete service designed to get your truck back on the road quickly. By programming the module to your VIN, we ensure all factory settings for your specific build are correctly loaded. This includes engine and transmission calibrations, emissions parameters, and security information. While the module is programmed for your vehicle, please be aware that on many GM vehicles of this era, a security relearn procedure (often called Passlock or VATS relearn) and a Crankshaft Variation Relearn (CASE relearn) may need to be performed after installation. These procedures can often be done without special tools and instructions are widely available online.
This PCM is a direct replacement for multiple part numbers, including 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810. It fits a wide range of GM trucks, vans, and SUVs from 1998-1999, such as the Chevrolet Silverado, Tahoe, Suburban, Express, GMC Sierra, Yukon, Savana, Cadillac Escalade, and more. Please verify your part number and consult the detailed fitment list to ensure compatibility.
Frequently Asked Questions
Do I need to have this computer programmed?
No. We handle all the programming for you before shipment. Just provide your vehicle’s VIN during or after checkout, and the module will arrive ready to be installed.
Is this a new part?
No, this is a high-quality, tested, and fully functional used OEM part sourced from a salvaged vehicle. This allows us to provide a reliable, factory-correct part at an excellent value.
What is a CASE Relearn?
A CASE (Crankshaft Angle Sensor Error) relearn is a procedure that synchronizes the new PCM with the engine’s crankshaft position sensor. It’s often required after replacing a PCM on these GM vehicles to prevent a P1336 trouble code. This procedure typically requires a capable scan tool.
Will this fix my transmission shifting problems?
The PCM controls both the engine and the transmission. If your shifting problems are caused by a faulty computer, then yes, this part will resolve them. However, shifting issues can also be caused by mechanical problems within the transmission itself.
How do I find my vehicle’s VIN?
Your 17-digit VIN can be found on your vehicle’s registration, insurance card, or on a metal plate on the driver’s side of the dashboard, visible through the windshield.