Restore Peak Performance to Your GMT400 Truck
Is your trusty 1998-1999 GMC 2500 pickup suddenly running rough, shifting erratically, or showing a persistent Check Engine Light? Before you start throwing parts at it, the problem could be its electronic heart: the Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen countless of these reliable trucks sidelined by a failing PCM. This isn’t just a part; it’s the central command for your engine and transmission. We offer a dependable solution: a high-quality replacement 1998-1999 GMC 2500 PCM, professionally programmed with the latest GM software specifically for your vehicle.
Forget the hassle and expense of a dealership visit. Simply provide us with your vehicle’s VIN (Vehicle Identification Number) during checkout, and we’ll handle the programming. This ensures that when the module arrives, it’s a true plug-and-play part, ready to restore your truck’s factory performance, fuel efficiency, and smooth operation. This module is a direct replacement for part numbers 16250279, 09366810, and 09355699.
From the Diagnostic Bay
I remember a ’99 Chevy Suburban that came into the shop with a ghost of a problem. The owner complained of intermittent stalling at stoplights and a transmission that couldn’t decide which gear it wanted. No consistent codes, just frustration. We checked grounds, sensors, and wiring for hours. Finally, on a hunch, we connected a scope to the PCM outputs and saw the 5-volt reference signal fluctuating wildly when the engine bay got hot. A replacement PCM, programmed to the VIN, solved everything in one shot. These internal failures are common and can mimic a dozen other issues, making a reliable replacement 1998-1999 GMC 2500 PCM the smartest fix.
Is Your GM Truck Showing These Telltale Signs?
- ✔ Persistent Check Engine Light that won’t clear.
- ✔ Diagnostic Trouble Codes (DTCs) like P0601 (Internal Control Module Memory Check Sum Error) or P0605 (Internal Control Module ROM Error).
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Unexplained drop in fuel economy.
- ✔ Engine cranks but refuses to start (no-start condition).
- ✔ Stalling, hesitation, or rough idling.
- ✔ Failure to pass state emissions testing.
A Straightforward Guide to Swapping Your PCM
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- ✔ Locate the PCM: On most of these GM trucks and SUVs, the PCM is located in the engine compartment on the driver’s side, often near the battery or firewall.
- ✔ Disconnect the Connectors: Carefully unclip and remove the large wiring harness connectors from the old module. They are often color-coded. Take care not to damage the locking tabs.
- ✔ Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s typically held in by a few bolts or nuts.
- ✔ Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten it.
- ✔ Reconnect Everything: Plug the wiring harnesses back into the correct sockets on the new module. Reconnect the negative battery terminal.
- ✔ Final Step (Important): While the PCM is programmed, you may need a local mechanic to perform a Crankshaft Variation Relearn (CASE Relearn) with a capable scan tool for optimal performance and to clear any related codes.
Verified Fitment For These GM Models
This module is a confirmed fit for a wide range of GM trucks, vans, and SUVs. While this is a 1998-1999 GMC 2500 PCM, please verify your original part number or consult the list below. This part fits vehicles requiring service ID 16250279, 09366810, or 09355699.
- ✔ Cadillac Escalade: 1999
- ✔ Chevrolet/GMC Pickups (1500, 2500, 3500): 1998-1999 (Gasoline Engines)
- ✔ Chevrolet/GMC Suburban & Tahoe/Yukon: 1998-1999 (Gasoline Engines)
- ✔ Chevrolet Astro / GMC Safari: 1998-1999
- ✔ Chevrolet Express / GMC Savana Vans (1500, 2500, 3500): 1998 (Gasoline Engines)
- ✔ Chevy S10 / GMC Sonoma / Jimmy / Blazer / Olds Bravada / Isuzu Hombre: 1998 (4.3L V6, check specific options)
Frequently Asked Questions
Do I need to do anything after installing this PCM?
Our programming handles the main vehicle operating system. However, for perfect operation, we highly recommend having a Crankshaft Position Sensor Relearn (also known as a CASE relearn) performed with a professional scan tool. Some vehicles may also require a security relearn procedure, which can typically be done without special tools.
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your 17-digit VIN. We cannot program and ship the module without it.
Is this a guaranteed fix for my truck’s problems?
This PCM will solve issues directly caused by a faulty module. It’s crucial to properly diagnose your vehicle, as symptoms like a misfire or no-start can also be caused by bad sensors, wiring, or fuel system components. This part is often the solution for codes like P0601 or P0605.
What if my original part number is slightly different?
This module is a direct replacement for part numbers 16250279, 09366810, and 09355699. As long as your original module is one of these numbers, this part will work perfectly once programmed to your VIN.