Is Your 1999-2000 Sierra 2500 Acting Possessed?
You turn the key, and… nothing. Or maybe it cranks but won’t fire. Perhaps it starts but runs terribly, lurching, stalling at lights, or shifting with a mind of its own. In my 20+ years as a diagnostic tech, few components can cause such a wide and frustrating range of symptoms as a failing Powertrain Control Module (PCM). It’s the brain of your truck, and when it starts to go, it can feel like you’re chasing ghosts in the machine.
These early GMT800 trucks are workhorses, but their electronics are now over two decades old. The PCM, located under the battery tray on the driver’s side, lives in a harsh environment. It’s subjected to constant vibration, extreme engine bay temperatures, and potential corrosion from battery acid leaks. Over time, these factors can cause internal solder joints to crack and electronic components to fail, leading to baffling issues that don’t always set a clear trouble code.
Common Symptoms of a Failing Sierra 2500 PCM
If you’re nodding along, you’ve likely experienced one or more of these classic PCM failure signs. I’ve personally diagnosed hundreds of these, and the patterns are often the same:
- ✔ Complete no-start or intermittent starting problems.
- ✔ Engine cranks but won’t catch, indicating a lack of fuel or spark command.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The “Check Engine Light” is on with multiple, unrelated diagnostic trouble codes (DTCs).
- ✔ Loss of communication between the PCM and your scan tool.
- ✔ Poor fuel economy and a noticeable drop in engine power.
- ✔ Stalling for no apparent reason, either at idle or while driving.
Expert Pro Tip: Check Your Grounds First!
Before you condemn your PCM, do yourself a huge favor and check the main ground connections. On these trucks, I’ve seen a corroded or loose ground strap between the engine block and the frame cause symptoms identical to a bad PCM. Also, inspect the ground wires at the PCM connector itself. A few minutes with a wire brush and a wrench has saved my customers hundreds of dollars and correctly solved the problem more times than I can count. A good computer with a bad ground is still a bad computer.
The Direct-Fit, Programmed Solution
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take a fully tested, reliable PCM and flash it with the latest official GM software calibration specifically for your truck. This is the critical step that makes all the difference.
How it works: After you place your order, you’ll provide us with your truck’s 17-digit Vehicle Identification Number (VIN). Using professional-grade equipment, we load the exact software your 1999-2000 Sierra 2500 requires. This ensures all parameters for the engine, transmission, and emissions systems are perfectly matched to your vehicle’s original specifications.
Why is VIN Programming So Important?
- ✔ Guaranteed Compatibility: It eliminates guesswork and ensures the module communicates correctly with all other systems in your truck.
- ✔ No Dealer Visit Needed: A non-programmed module is just a metal box. It would require you to have the truck towed to a dealership for expensive programming. Our service saves you that time, hassle, and cost.
- ✔ Latest GM Updates: We flash the module with the most current software available from General Motors. These updates often contain fixes for drivability issues, shifting problems, and other bugs that were present in the original software.
- ✔ Plug-and-Play Installation: For most vehicles on the fitment list, installation is straightforward. Once installed, you may need to perform a simple security relearn procedure, which typically involves cycling the key and can be done in your driveway in about 10-15 minutes. No special tools required.
Part Number and Fitment Information
This module is a direct replacement for the following GM part numbers: 09354896, 9354896, and 19109040.
While this listing is focused on the 1999-2000 Sierra 2500, this versatile PCM was used across a wide range of GM vehicles. Please verify your part number and check the list below to confirm fitment for your specific application:
- ✔ Chevrolet Corvette: 1999-2000
- ✔ Chevrolet Camaro: 1999-2002 (5.7L)
- ✔ Pontiac Firebird: 1999-2002 (5.7L)
- ✔ Chevrolet Silverado 1500/2500: 1999-2000
- ✔ GMC Sierra 1500/2500: 1999-2000
- ✔ Chevrolet Tahoe / Suburban 1500 & 2500: 2000
- ✔ GMC Yukon / Yukon XL 1500 & 2500: 2000
Stop chasing electrical gremlins and restore the reliability of your truck. This pre-programmed PCM is the most effective and efficient way to get your Sierra 2500 back on the road and running strong. Order today and provide your VIN to get the process started.