Is Your 1998-1999 Chevy Truck Running Rough?
If your dependable Chevrolet 3500 Pickup is suddenly experiencing issues like stalling, poor fuel economy, erratic shifting, or a persistent Check Engine Light, the root cause might be a failing Powertrain Control Module (PCM). As the central computer of your vehicle, the PCM is responsible for managing everything from the fuel injectors and ignition timing to the transmission shift points. When it starts to fail, it can cause a wide range of frustrating and difficult-to-diagnose problems that can sideline your workhorse truck.
The Direct-Fit Solution for Your GMT400 Truck
Don’t let a faulty computer keep you off the road. This is a genuine, road-tested used PCM, service number 16258815, that serves as a direct replacement for your original unit. The biggest advantage of our service is that we program the module specifically for your truck before it ever leaves our facility. Simply provide us with your vehicle’s 17-digit VIN (Vehicle Identification Number) during checkout, and we will flash the computer with the latest GM-certified software updates. This ensures that when the part arrives, it’s ready for a straightforward installation, saving you a costly trip to the dealership for programming.
From the Diagnostic Bay
We had a 1999 Suburban come in that was driving the owner crazy. It would randomly stall at stoplights, and the transmission would sometimes refuse to shift out of first gear. He had already replaced the fuel pump and a handful of sensors with no luck. After hooking up our scanner, we noticed some very erratic data coming from the PCM and a few communication error codes. We suspected an internal failure in the module. Instead of a costly new unit from the dealer, we sourced a quality used PCM like this one, programmed it to the Suburban’s VIN, and installed it. The truck immediately ran perfectly. It was a classic case of a failing computer mimicking other mechanical problems, and a simple, pre-programmed replacement was the key to getting it fixed right.
Diagnosing a Faulty 1998-1999 Chevy 3500 PCM
A failing engine computer can manifest in numerous ways. If you’re experiencing several of the following symptoms, there’s a strong possibility your PCM is the culprit. This module is the brain behind your truck’s performance, and any internal fault can have a cascading effect on the entire powertrain.
Common Symptoms of a Failing PCM:
- ✔ Check Engine Light: The light may be on constantly or intermittently, often with communication-related trouble codes (U-codes) or multiple, unrelated sensor codes.
- ✔ Engine Stalling: Your truck may stall for no apparent reason, either while driving or when coming to a stop.
- ✔ No-Start Condition: The engine cranks but refuses to start, even with good fuel pressure and spark.
- ✔ Poor Engine Performance: You may notice a significant loss of power, hesitation during acceleration, or rough idling.
- ✔ Reduced Fuel Economy: A faulty PCM can’t efficiently manage the engine’s fuel delivery, leading to a noticeable drop in MPG.
- ✔ Erratic Transmission Shifting: The PCM also controls the transmission, so a failure can cause harsh shifts, delayed shifting, or getting stuck in one gear.
- ✔ Failure to Communicate: A diagnostic scan tool may be unable to connect with the PCM, which is a definitive sign of a major internal issue.
Simple Installation Process
Replacing the PCM is a job most DIY mechanics can handle. The module is typically located in the engine bay on the driver’s side. After disconnecting the battery, you simply unbolt the old unit, carefully unplug the wiring harnesses, and install the new one in its place. Because we’ve already programmed this module to your VIN, you can skip the expensive dealer visit. However, please be aware that on many of these GM vehicles, you will need to perform a security relearn procedure (also known as a CASE relearn or Crankshaft Variation Relearn) after installation. This procedure can often be done without special tools and instructions can be readily found online for your specific model.
Guaranteed Fitment
This PCM, identified by part number 16258815 and service number 09355699, is a compatible replacement for a wide range of 1998-1999 GM trucks, vans, and SUVs. It interchanges with several other part numbers, including 16266645, 9355699, 16250279, and 09366810. Please verify the part number on your original computer to ensure a perfect match for your Chevrolet, GMC, Cadillac, or Isuzu vehicle.
Frequently Asked Questions
Do I need to get this computer programmed?
No. We handle all the programming for you before shipping. Just provide your vehicle’s VIN at checkout, and it will arrive ready to install with the latest GM software updates.
Where do I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) is typically located on a metal plate on the driver’s side dashboard (visible through the windshield), on the driver’s side door jamb sticker, and on your vehicle’s registration and insurance documents.
Is this a new part?
This is a high-quality, tested, and fully functional used OEM part sourced from a salvaged vehicle. This ensures perfect factory fitment and operation at a fraction of the cost of a new unit.
What else needs to be done after I install it?
After installation, you will likely need to perform a security relearn procedure, often called a CASE relearn. This syncs the new computer with your vehicle’s anti-theft system and crankshaft position sensor. This procedure can typically be done without special tools.
How can I be sure this fits my vehicle?
The best way to ensure compatibility is to match the part number (e.g., 16258815) or the service number (e.g., 09355699) from your original computer to the numbers listed in this description. If you are unsure, please contact us with your VIN.