Is Your GM Truck or Van Running Rough?
If your 1998-1999 GMC 3500, or another compatible GM vehicle, is experiencing baffling issues like a persistent check engine light, erratic shifting, poor fuel economy, or even a no-start condition, the problem might be its electronic brain: the Powertrain Control Module (PCM). The PCM is the central command center for your vehicle’s engine and transmission, and when it starts to fail, it can cause a wide range of frustrating and hard-to-diagnose problems. Don’t let a faulty computer keep your reliable truck off the road. This is your direct-fit, hassle-free solution.
From the Diagnostic Bay
We had a 1999 Chevy Suburban come in that had its owner completely stumped. The truck would crank but wouldn’t start, and there were no trouble codes stored. The fuel pump was working, and it had spark. After hours of checking wiring and sensors, we hooked up our scan tool and found we couldn’t communicate with the factory PCM at all. It was a classic case of internal module failure. We sourced a quality used unit just like this one, programmed it to the customer’s VIN, and performed the security relearn. The Suburban fired right up on the first try and ran perfectly. A simple module swap, when correctly programmed, saved the customer from what could have been a massive and expensive diagnostic headache.
Symptoms of a Failing Powertrain Control Module
- ✔ Check Engine Light is on with various, often unrelated, trouble codes.
- ✔ Vehicle will not start or is difficult to start.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine stalling, stuttering, or misfiring while driving.
- ✔ Failure to pass an emissions inspection.
- ✔ Loss of communication with the scan tool.
Your Plug-and-Play Solution: The 1998-1999 GMC 3500 PCM
Replacing a PCM isn’t just about swapping a box. Modern vehicles require precise software that matches your vehicle’s specific options and Vehicle Identification Number (VIN). This used PCM is taken from a salvaged vehicle and is professionally programmed to your exact VIN before it ships. This critical step ensures that the computer works seamlessly with your truck’s engine, transmission, and security systems. By providing us with your VIN upon purchase, you receive a part that is ready for installation, saving you a costly trip to the dealership for programming.
This module is a direct replacement for multiple part numbers, including 09355699, 16266645, 16250279, 16258815, and 09366810. Please verify the part number on your original module or consult our extensive fitment list below to ensure compatibility with your specific make, model, and engine.
Frequently Asked Questions
Why do I need to provide my VIN?
Your Vehicle Identification Number (VIN) contains crucial information about your truck’s specific build, including engine size, transmission type, and emissions equipment. We use the VIN to load the correct factory software and calibrations onto the PCM, ensuring it functions perfectly with your vehicle right out of the box.
Is this a plug-and-play part?
Yes, because we program it to your VIN, it is designed to be a plug-and-play installation. However, many GM vehicles of this era require a simple security relearn procedure (often called a Passlock or VATS relearn) after installation, which can typically be done without special tools. Instructions for this procedure are widely available online.
Is this a new computer?
No, this is a genuine, factory-original PCM that has been carefully removed from a salvaged vehicle. Each unit is inspected and tested to ensure it is fully functional before being programmed and shipped to you.
How do I find my original part number?
Your vehicle’s original PCM part number is printed on a sticker on the module itself. On most GM trucks and vans from this period, the PCM is located in the engine bay, often on the driver’s side fender or near the battery.
Will this fix my check engine light?
If the check engine light and associated symptoms are caused by a faulty PCM, then replacing it with this correctly programmed unit will resolve the issue. It is always recommended to have the vehicle properly diagnosed to confirm the PCM is the root cause of the problem before ordering.