Is Your 1999-2000 Tahoe or GM Truck Acting Possessed?
If your trusty Tahoe, Silverado, or Express van is suddenly giving you fitsโstalling at stoplights, shifting erratically, or refusing to start altogetherโthe problem might be deeper than spark plugs or a battery. As a mechanic with over two decades of experience, I’ve seen these symptoms hundreds of times, and the trail often leads directly to a failing Powertrain Control Module (PCM), the electronic brain of your vehicle.
These late-90s GM trucks are legendary for their durability, but after 20+ years of heat cycles, vibrations, and electrical demands, the original PCM can start to break down internally. The solder joints crack, the capacitors weaken, and the driver circuits that control everything from fuel injectors to ignition coils can fail, leaving you stranded and scratching your head.
Common Symptoms of a Failing GM PCM
A failing PCM doesn’t always die suddenly. It often gives warning signs that can be mistaken for other issues. If you’re experiencing any of these, it’s time to suspect the module:
- โ Check Engine Light is on with communication error codes (like U-codes) or specific circuit failure codes.
- โ The engine cranks but refuses to start, even with good fuel pressure and spark.
- โ Unexplained stalling, especially after the engine has warmed up.
- โ Harsh or erratic automatic transmission shifting.
- โ A noticeable drop in fuel economy and overall engine performance.
- โ The anti-theft or security light stays on, preventing the engine from running.
Expert Pro Tip: The Critical Importance of VIN Programming
In my shop, I’ve seen countless DIYers and even some new technicians make a critical mistake: they grab a used PCM from a salvage yard, plug it in, and wonder why the truck won’t start. On these GM vehicles, the PCM is tied directly to the vehicle’s VIN and its Passlock/VATS anti-theft system. A mismatched module will immediately trigger the security system, permanently disabling the vehicle until it’s correctly programmed with a dealership-level scan tool. Our service eliminates this massive headache. We flash the module with your specific VIN and the latest GM software before it ever leaves our facility. This makes the installation process as close to plug-and-play as possible, saving you a trip to the dealer and a hefty programming fee.
The Definitive, Reliable Solution
Don’t let a faulty computer sideline your vehicle. This Powertrain Control Module is a direct-fit replacement, meticulously tested and prepared to restore your vehicle’s factory operation. The key is our professional programming service. When you provide us with your Vehicle Identification Number (VIN) after purchase, we load the module with the correct software calibration straight from GM’s library. This ensures all components communicate perfectly, just as they did when your truck rolled off the assembly line.
Why Our Programmed PCM is the Smart Choice
- โ VIN-Programmed for Your Vehicle: We handle the complex software flashing so you don’t have to. This ensures compatibility with your engine, transmission, and options.
- โ Loaded with GM Updates: Your module comes with the newest available software, which often corrects factory bugs related to idle stability and transmission logic.
- โ Restores Lost Performance: A healthy PCM provides precise fuel and spark control, bringing back the power and efficiency you’ve been missing.
- โ Direct-Fit Replacement: Guaranteed to physically fit and connect to your factory wiring harness without any modifications.
Installation and Compatibility
Replacing the PCM is typically straightforward. On most Tahoes, Yukons, and pickups, it’s located in the engine compartment on the driver’s side. On Express and Savana vans, it’s often in the LH rear of the engine compartment. Simply disconnect the battery, unplug the wiring harnesses from the old module, unbolt it, and install the new one in its place. After reconnecting the battery, you may need to perform a simple Security Relearn procedure, which can be done without any special tools. Instructions are readily available online for your specific model.
This module is a direct replacement for the following part numbers:
- โ 16263494
- โ 16265035
- โ 8162634940
- โ 218-11787
- โ 21811787
It is compatible with a wide range of Chevrolet, GMC, Isuzu, and Oldsmobile trucks, vans, and SUVs from roughly 1998 to 2002. Please use the compatibility chart and verify the part number on your original module to ensure a perfect match for your vehicle.