Restore Peak Performance to Your GMT400 Truck
Is your 1998 or 1999 Chevrolet 3500 Pickup running rough, stalling, or refusing to start? Are you battling a persistent Check Engine Light with frustrating communication error codes? The Powertrain Control Module (PCM), the electronic brain of your truck’s engine and transmission, is often the culprit. This vital component manages everything from fuel injection and ignition timing to transmission shift points. When it fails, it can cause a wide range of debilitating issues. This listing offers a direct, reliable solution: a genuine, used OEM PCM, part number 9366810, fully programmed to your truck’s specific Vehicle Identification Number (VIN).
From the Diagnostic Bay
We had a ’99 Chevy K3500 dually come into the shop with a bizarre, intermittent no-start condition. It would run perfectly for days, then suddenly refuse to fire up. The owner had already replaced the battery, starter, and fuel pump. Scans were inconsistent, sometimes showing no codes, other times showing a loss of communication with the PCM. After checking all the grounds and power feeds to the computer, we suspected the PCM itself was failing internally. We swapped in a VIN-programmed module just like this one, and the truck fired up instantly. The problem never returned. These intermittent electronic gremlins are classic signs of a failing PCM, and a correctly programmed replacement is the definitive fix.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) illumination
- ✔ Engine stalling, stumbling, or misfiring
- ✔ Complete no-start or intermittent starting issues
- ✔ Poor fuel economy and reduced engine power
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Diagnostic scanner cannot communicate with the PCM
- ✔ Unexplained warning lights on the instrument cluster
The Importance of a VIN-Programmed 1998-1999 Chevrolet 3500 PCM
Simply installing a used computer from another vehicle will not work. The PCM is a sophisticated component that must be precisely matched to your truck’s specific configuration, including its engine size, transmission type, axle ratio, and factory options. Our professional programming service eliminates the guesswork and the need for an expensive trip to a dealership. When you provide us with your VIN, we flash the module with the latest official GM software updates for your exact vehicle. This ensures all parameters are set correctly for optimal performance, fuel efficiency, and emissions compliance. It’s a true plug-and-play solution designed to get your heavy-duty truck back to work.
This module is a tested, used component sourced from a salvaged vehicle, offering OEM quality and a perfect fit without the high cost of a new part. It is a direct replacement for several part numbers, including 09355699, 16266645, 16250279, 16258815, and 09366810. While this listing is focused on the 1998-1999 Chevrolet 3500 PCM, this versatile computer also fits a wide range of other GM trucks and vans from the same era, such as the Suburban, Tahoe, Yukon, Express, Savana, and more. Please verify your part number and consult the fitment list to ensure compatibility.
Frequently Asked Questions
Do I need to get this computer programmed?
No, we handle the programming for you before shipment. Simply provide your vehicle’s VIN during or after checkout, and we will flash the computer with the correct software for your truck. This makes installation much simpler.
Is this a new part?
This is a high-quality, tested, and fully functional used OEM part. It was carefully removed from a salvaged vehicle and has been inspected to ensure it meets operational standards.
What is a CASE relearn and will I need to perform one?
A CASE (Crankshaft Angle Sensor Error) relearn procedure may be required after installation to sync the new PCM with your engine’s crankshaft position sensor. This prevents a P1336 trouble code. Many professional-grade scan tools can perform this procedure in a few minutes.
Where is the PCM located on my 1998-1999 Chevy 3500?
On most of these trucks, the PCM is located in the engine compartment on the driver’s side, often near the firewall or inner fender. It’s a silver metal box with multiple large electrical connectors.
How do I provide my VIN?
You can add your 17-digit VIN to the notes section during checkout or send it to us in a message after you complete your purchase. We cannot ship your order until we receive the VIN for programming.