Is Your Late-90s GM Truck or SUV Running Rough?
If you’re dealing with frustrating issues like a persistent check engine light, poor fuel economy, erratic shifting, or even a no-start condition in your 1998 or 1999 GM vehicle, the problem might be deeper than a simple sensor. The Powertrain Control Module (PCM), often called the Electronic Control Module (ECM), is the central computer of your vehicle. It’s responsible for managing everything from fuel injection and ignition timing to transmission shift points and emissions controls. When it fails, it can cause a wide range of confusing and difficult-to-diagnose symptoms.
Don’t let a faulty computer keep your reliable GM truck off the road. This is a genuine, used GM PCM, part number 16258815 (interchangeable with 09355699 and others listed), that has been carefully inspected and is ready to be programmed specifically for your vehicle. We take the guesswork out of the repair by flashing the module with the latest official GM software updates, tailored precisely to your Vehicle Identification Number (VIN). This ensures a seamless, plug-and-play installation process without the need for expensive dealership tools or programming.
From the Diagnostic Bay
We had a 1998 Chevy K1500 come into the shop that was driving the owner crazy. It would start and run fine for about 15 minutes, then suddenly die and refuse to restart for an hour. He had already replaced the fuel pump, ignition coil, and crank sensor. We hooked up our scanner and noticed that when the truck stalled, we lost all communication with the PCM. After letting it cool down, communication would return. This is a classic sign of thermal failure inside the module. The solder joints on the main processor or driver circuits crack over time, and as the PCM heats up, the connection is lost. We installed one of our VIN-programmed PCMs, and the truck has been running perfectly ever since. It’s a common issue on these GMT400-era vehicles, and a correctly programmed replacement is the definitive fix.
Why a VIN-Programmed 1998 GM Truck PCM is Essential
Simply swapping a used PCM from another vehicle will not work. The PCM’s software is calibrated for a specific combination of engine, transmission, emissions equipment, and even tire size. More importantly, for many of these vehicles, the PCM is a critical part of the Vehicle Anti-Theft System (VATS) or Passlock system. An incorrect module will prevent the engine from starting. Our service eliminates these headaches. By providing us with your VIN, you receive a module that is a direct, functional replacement for your original, with all the correct settings and security information loaded and ready to go.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light is on with communication-related or internal processor fault codes (e.g., P0601, P0605).
- ✔ Engine cranks but will not start.
- ✔ Stalling for no apparent reason, especially after warming up.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Noticeable drop in fuel mileage.
- ✔ Misfires or rough idling that can’t be traced to spark plugs, coils, or injectors.
- ✔ Failure to communicate with a diagnostic scan tool.
- ✔ Intermittent issues with gauges or other electronic components.
Simple Installation Process
Replacing the PCM is a straightforward job for a DIY mechanic. It is typically located in the engine bay. Simply disconnect the negative battery terminal, unplug the electrical connectors from the old PCM, unbolt it from its bracket, and install the new one in its place. Reconnect the connectors and the battery terminal. Because we’ve already programmed it to your VIN, in most cases, the vehicle will start and run correctly immediately. For vehicles with certain anti-theft systems, a simple security relearn procedure (which can be done without special tools) may be required. We can provide instructions for this process.
This module is a direct replacement for multiple part numbers, including 09355699, 16266645, 9355699, 16250279, 16258815, 09366810, and 9366810. Please verify the part number on your original module or consult the extensive fitment list to ensure compatibility.
Frequently Asked Questions
Do I need to send my old PCM back?
No, there is no core charge or need to return your old, non-functional module. This is an outright purchase.
How do I provide my VIN?
After you complete your purchase, you can send us a message with your 17-digit Vehicle Identification Number (VIN). We cannot ship your order until we receive this information, as the programming is essential.
Is any additional programming needed after installation?
In most cases, no. The module is sent to you ready to install. Some vehicles may require a security relearn procedure, which is a simple process you can do yourself in your driveway. Instructions can be provided upon request.
What if my original part number isn’t 16258815?
This PCM is a direct replacement for several part numbers, with 09355699 being the most common service ID. As long as your vehicle and original part number are on our compatibility list, this module will work correctly once programmed to your VIN.
Is this a new part?
No, this is a high-quality, tested, and inspected used part from a salvaged vehicle. We ensure it is fully functional before programming and shipping it to you. This provides a reliable and cost-effective solution.