Is Your 1998-1999 GMC Truck Running Rough?
If your reliable GMC 3500, or a similar GM truck or van from that era, is suddenly plagued by mysterious issues like stalling, erratic shifting, a persistent check engine light, or a complete no-start condition, the problem might be deeper than a simple sensor. The Powertrain Control Module (PCM), the electronic brain of your vehicle, is often the culprit. When it fails, it can cause a cascade of frustrating and difficult-to-diagnose problems. This genuine used PCM, part number 09366810, is the reliable and cost-effective solution to restore your vehicle’s performance and get you back on the road with confidence.
From the Diagnostic Bay
We had a ’99 Chevy Suburban come in that had its owner chasing his tail for weeks. The truck would randomly die at stoplights, the transmission would shift hard, and the fuel gauge was acting possessed. He’d replaced the fuel pump and a couple of sensors with no luck. After hooking up our scanner, we noticed communication with the PCM was intermittent. We checked the power and ground connections to the module, and they were solid. On a hunch, we swapped in a known-good, programmed PCM. The truck fired right up and ran perfectly. The original PCM had internal circuit failure, causing all those ghost-like symptoms. It’s a classic case where the central computer is the problem, not the parts it’s controlling.
Common Symptoms of a Failing PCM
- ✔ Check Engine Light is on with various, often unrelated, trouble codes.
- ✔ Engine stalling, misfiring, or running poorly.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Complete no-start condition where the engine cranks but won’t fire.
- ✔ Decreased fuel economy for no apparent reason.
- ✔ Failure to communicate with a diagnostic scan tool.
- ✔ Issues with gauges or other electronic components.
The Direct-Fit Solution: A Programmed 1998-1999 GMC 3500 PCM
Don’t let a faulty computer sideline your workhorse. This isn’t just a generic, off-the-shelf part. We take a genuine, used GM PCM and program it specifically to your vehicle’s Vehicle Identification Number (VIN). This critical step ensures that the module has the correct software and calibrations for your truck’s specific engine, transmission, and options. By using the latest updates available from GM, we ensure optimal performance and compatibility, essentially making it a plug-and-play replacement.
This module is a direct replacement for a wide range of GM trucks and vans from the late 90s, including the Chevrolet 1500/2500/3500 pickups, Suburban, Tahoe, Express vans, and their GMC counterparts like the Sierra, Yukon, and Savana. It is compatible with multiple service numbers, including 09355699, 16266645, 16250279, 16258815, and 09366810. Please verify the part number on your original module to ensure a perfect match.
Simple Process, Powerful Results
- ✔ Place Your Order: Complete your purchase for this PCM.
- ✔ Provide Your VIN: After ordering, simply send us your 17-digit VIN. This is crucial for the programming process.
- ✔ We Program It: Our technicians will flash the module with the correct GM software for your specific vehicle.
- ✔ We Ship It: Your ready-to-install PCM is shipped directly to you.
Once you receive the module, installation is straightforward. In most cases, you will need to perform a security relearn procedure (often called a Passlock or VATS relearn) after installation. This is a simple process that pairs the new computer to your vehicle’s anti-theft system and typically does not require special tools. Instructions for this procedure can be easily found online or in a service manual for your vehicle.
Frequently Asked Questions
What is a PCM and what does it do?
The Powertrain Control Module (PCM) is your vehicle’s main computer. It controls all aspects of the engine and transmission, such as fuel injection, ignition timing, and shift points, to ensure optimal performance, fuel efficiency, and emissions.
Why do you need my VIN?
Your Vehicle Identification Number (VIN) contains specific information about your truck’s engine, transmission, and factory options. We use the VIN to load the exact, correct software from GM onto the PCM, ensuring it works perfectly with your vehicle right out of the box.
Is this part difficult to install?
Physically replacing the PCM is typically easy, involving disconnecting the battery and unplugging a few electrical connectors. The most important step after installation is the security relearn procedure, which syncs the new PCM with your vehicle’s anti-theft system. This procedure is straightforward and can usually be done without a mechanic.
Is this a new part?
No, this is a high-quality, tested, genuine used part sourced from a salvaged vehicle. This provides an affordable and reliable alternative to a costly new module from a dealership.
Will this fix my check engine light?
If the check engine light and other symptoms are caused by a faulty PCM, this replacement module will solve the problem. However, it’s always best to have your vehicle properly diagnosed to confirm the PCM is the root cause before ordering.