Restore Peak Performance to Your GM Truck or Van
Is your trusty 1998-1999 GMC 2500 Pickup suddenly giving you headaches? Unexplained check engine lights, rough idling, stalling, or harsh transmission shifts can often be traced back to a single, critical component: the Powertrain Control Module (PCM). As a technician with over two decades of experience under the hood, I’ve seen countless owners chase expensive sensor and component replacements, only to find the root cause was the vehicle’s computer all along. The PCM is the brain of your engine and transmission, and when it starts to fail, the symptoms can be frustratingly inconsistent.
This isn’t just a replacement part; it’s a reliable, cost-effective solution. We offer a genuine, used OEM PCM that has been meticulously tested and is ready for a new life in your vehicle. The real value lies in our expert programming service. Before this module ships, we flash it with the latest GM software updates specifically matched to your vehicle’s VIN. This critical step ensures seamless communication between the PCM and all other systems in your truck, eliminating the need for an expensive trip to the dealership for programming. It’s a plug-and-play fix designed to get you back on the road quickly and affordably.
From the Diagnostic Bay
I remember a 1999 Chevy Suburban that came into my shop with a complaint of intermittent stalling at stop lights and a random ‘no-start’ condition that would happen once every few weeks. The owner had already replaced the fuel pump and ignition coil pack with no success. A scan showed no hard codes, just a history of communication loss faults. On these GMT400 platform trucks, this is a classic sign of a failing PCM. The internal processors and capacitors weaken over time from heat cycles, causing these bizarre, hard-to-diagnose issues. We swapped in a VIN-programmed PCM like this one, performed the quick security relearn, and the truck ran perfectly. It’s a fix I’ve performed hundreds of times, saving customers time and money.
Is Your Truck Showing These Telltale Signs?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, a faulty computer could be the culprit:
- ✔ Check Engine Light is on, often with internal processor codes like P0601, P0604, or P0606.
- ✔ Vehicle refuses to start or has intermittent no-start issues.
- ✔ Poor fuel economy and a noticeable loss of engine power.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Engine stalling, stumbling, or running rough for no apparent reason.
- ✔ Failure to communicate with a diagnostic scan tool.
DIY-Friendly Installation: A Step-by-Step Guide
Replacing the PCM on these GM trucks is a straightforward job that most DIY enthusiasts can handle in their own driveway. This 1998-1999 GMC 2500 PCM is designed for a direct fit.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect the Connectors: Carefully unclip and remove the large electrical harness connectors from the old PCM. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt your new, pre-programmed PCM into the mounting bracket.
- Reconnect Everything: Firmly plug the electrical connectors into the new PCM until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: You will likely need to perform a simple security or CASE (Crankshaft Angle Sensor Error) relearn procedure. This can typically be done without special tools. A common method is the ’10-Minute Relearn’: Turn the key to ‘ON’ for 10 minutes, then ‘OFF’ for 10 seconds, and repeat two more times. Then, the vehicle should start.
Verified Compatibility for Your GM Vehicle
This Electronic Control Module is a direct replacement for several part numbers, including 09355699, 16266645, 16250279, 16258815, and 9366810. It is guaranteed to fit the following vehicles with the specified options, referencing service ID 9355699:
- ASTRO 98 (LH front by battery)
- BLAZER S10/JIMMY S15 98 (RH front engine compartment)
- BRAVADA 98 (6-262, 4.3L)
- CHEVROLET 1500 PICKUP 98-99 (Gasoline)
- CHEVROLET 2500 PICKUP 98-99 (Gasoline)
- CHEVROLET 3500 PICKUP 98-99 (Gasoline)
- ENVOY 98 (RH front engine compartment)
- ESCALADE 99 (LH front engine compartment)
- EXPRESS 1500 VAN 98-99
- EXPRESS 2500 VAN 98-99 (Gasoline)
- EXPRESS 3500 VAN 98-99 (Gasoline)
- GMC 1500 PICKUP 98-99 (Gasoline)
- GMC 2500 PICKUP 98-99 (Gasoline)
- GMC 3500 PICKUP 98-99 (Gasoline)
- ISUZU HOMBRE 98 (4.3L)
- S10/S15/SONOMA 98 (6-262, 4.3L)
- SAFARI (GMC) 98 (LH front by battery)
- SAVANA 1500 VAN 98-99
- SAVANA 2500 VAN 98-99 (Gasoline)
- SAVANA 3500 VAN 98-99 (Gasoline)
- SUBURBAN 1500 98-99 (Gasoline)
- SUBURBAN 2500 98-99 (Gasoline)
- TAHOE 98-99 (Gasoline)
- YUKON 98-99
Your Trusted Partner in Automotive Repair
Don’t let a faulty computer keep your reliable GM truck off the road. This programmed 1998-1999 GMC 2500 PCM is the smart, simple, and effective way to solve complex electronic issues and restore the dependable performance you rely on every day.
Frequently Asked Questions
How does the VIN programming work?
After you place your order, you will need to provide us with your vehicle’s 17-digit VIN. Our technicians use this number to access the latest official GM software for your specific vehicle and flash it onto the module before shipping. This ensures it works correctly right out of the box.
Is this a new part?
No, this is a high-quality, used OEM (Original Equipment Manufacturer) part sourced from a salvaged vehicle. Each unit is inspected and tested to ensure full functionality before being programmed and shipped.
Will I need to do anything else after installation?
In most cases, you will need to perform a simple ‘Security Relearn’ or ‘CASE Relearn’ procedure. This synchronizes the new PCM with your vehicle’s anti-theft and crankshaft position systems. This procedure typically does not require special tools and instructions can be easily found online for your specific model.
How do I find my current PCM’s part number to verify a match?
The part number is printed on a sticker on the PCM itself. While this module replaces many part numbers, verifying your original helps confirm compatibility. Our extensive fitment list covers all compatible vehicles for this part.
What if my part number is slightly different?
This module, identified by service ID 9355699, directly replaces several part numbers like 16266645, 9366810, and others. As long as your vehicle is on our fitment list, this programmed module is the correct replacement, even if the number on your old unit differs.