Get Your GM Truck Running Right Again
Is your 1998-1999 GMC 2500 Pickup giving you headaches? If you’re dealing with a no-start condition, a persistent check engine light, erratic shifting, or poor performance, the culprit is often the Powertrain Control Module (PCM). As the brain of your vehicle, when it fails, it can cause a host of frustrating and hard-to-diagnose problems. This isn’t just an inconvenience; it’s a critical component for your truck’s reliability and safety. We offer a dependable and straightforward solution: a tested, used OEM PCM, part number 16258815, that arrives at your door programmed specifically for your truck.
A Technician’s Notebook
I remember a ’99 Chevy Suburban that came into my bay with a complaint of randomly stalling at stoplights. The owner had already replaced the fuel pump and a handful of sensors with no luck. The check engine light was intermittent. After hooking up my scan tool, I noticed communication dropouts with the PCM. Instead of throwing parts at it, we tested the circuits and confirmed they were good. The issue was internal to the module itself—a classic case of an aging PCM. A replacement like this one, programmed with the vehicle’s VIN, solved the problem instantly. It’s a fix I’ve performed hundreds of times on these GM platforms; it saves time and gets the diagnosis right the first time.
Is Your Truck Showing These Telltale Signs?
A failing PCM can manifest in many ways. If you’re experiencing any of the following, it’s time to consider a replacement 1998-1999 GMC 2500 PCM:
- ✔ Check Engine Light is on with codes like P0601, P0602, P0605 (Internal Control Module Memory Error).
- ✔ Vehicle won’t start or is extremely difficult to start.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Engine stalling, sputtering, or misfiring for no apparent reason.
- ✔ No communication with your scan tool.
- ✔ Failure to pass an emissions inspection.
Your Straightforward Installation Guide
One of the biggest benefits of this module is that it comes programmed, making installation manageable for a DIYer or any professional mechanic. While specifics can vary slightly by model (e.g., van vs. truck), the general process is consistent.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- Locate the PCM: On most GM trucks and SUVs of this era, the PCM is located in the engine compartment, typically on the driver’s side inner fender or near the battery.
- Disconnect the Connectors: Carefully unclip and remove the wiring harness connectors from the old PCM. These connectors are color-coded and keyed, so they only go back on one way. Avoid forcing them.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely re-fasten the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Necessary): In many cases, you will need to perform a simple security relearn procedure to sync the new PCM with your vehicle’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your vehicle’s service information for the exact procedure.
By purchasing a pre-flashed 1998-1999 GMC 2500 PCM, you bypass the need for expensive dealership-only programming tools, saving you significant time and money.
Verified Compatibility for Your GM Vehicle
This module, identified by service number 16258815 or Hollander ID 590-05182, is a direct replacement for a wide range of GM trucks, vans, and SUVs. It is compatible with part numbers 09355699, 16266645, 16250279, and 09366810. Please verify your vehicle is on this list and that your original module carries one of these compatible part numbers.
This part fits the following vehicles:
- Cadillac Escalade: 1999
- Chevrolet/GMC C/K 1500, 2500, 3500 Pickups: 1998-1999
- Chevrolet/GMC Suburban 1500, 2500: 1998-1999
- Chevrolet Tahoe / GMC Yukon: 1998-1999
- Chevrolet Express / GMC Savana 1500, 2500, 3500 Vans: 1998-1999
- Chevrolet Astro / GMC Safari Vans: 1998
- Chevrolet S10 / GMC Sonoma: 1998
- Chevrolet Blazer / GMC Jimmy: 1998
- Oldsmobile Bravada: 1998
- Isuzu Hombre: 1998
What do I need to provide after I order?
What do I need to provide after I order?
After you complete your purchase, you must provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). We use this to program the PCM with the correct, latest GM software for your specific vehicle configuration before we ship it.
Is this PCM ready to install right out of the box?
Yes, it arrives programmed to your VIN. However, on most GM vehicles from this era, you will need to perform a simple ‘Security Relearn’ or ‘Passlock Relearn’ procedure so the module can communicate with your anti-theft system. This procedure does not require special tools and can be found online or in a service manual.
What is the difference between a PCM and an ECM?
The terms are often used interchangeably. ECM stands for Engine Control Module, while PCM means Powertrain Control Module. A PCM is a type of ECM that also controls the transmission and other powertrain functions, which is standard on most vehicles like your 1998-1999 GMC 2500 PCM.
Is this a new part?
No, this is a high-quality, tested, and fully functional used OEM part that has been sourced from a salvaged vehicle. We inspect and then program each unit to ensure it meets operational standards, offering a reliable and cost-effective alternative to a new dealer part.