Is Your GM Truck or SUV Plagued by Mysterious Electrical Gremlins?
If you’re driving a late-90s or early-2000s GM vehicle like a Blazer, Jimmy, or Silverado, you know they’re built to last. But when the Powertrain Control Module (PCM) starts to fail, it can create some of the most frustrating and hard-to-diagnose problems you’ll ever encounter. The engine’s computer is the brain of the entire operation, and when it gets faulty, your vehicle’s behavior can become erratic and unpredictable.
Common Symptoms of a Failing 16263494 PCM
A failing PCM doesn’t always result in a simple “Check Engine” light. Over my 20+ years in diagnostics, I’ve seen these modules cause issues that send both owners and less-experienced mechanics on a wild goose chase, replacing perfectly good parts. Look out for these tell-tale signs:
- ✔ Sudden and harsh transmission shifting or getting stuck in one gear (limp mode).
- ✔ Engine stalls for no reason, either while driving or at idle.
- ✔ A persistent no-start condition even with a good battery, starter, and fuel pressure.
- ✔ Multiple, unrelated diagnostic trouble codes (DTCs) that keep reappearing.
- ✔ Poor fuel economy and a noticeable loss of power.
- ✔ The anti-theft or security light stays on, preventing the engine from starting.
- ✔ Inconsistent or non-functional gauges on your instrument cluster.
From the Shop Floor: A Real-World Diagnostic Story
“A customer’s 1999 GMC Jimmy S15 came in last week with these exact symptoms. He was chasing a random misfire (P0300) and had already replaced the spark plugs, wires, distributor cap, and rotor. The engine still ran rough and would occasionally stall at red lights. His scan tool would intermittently lose communication with the PCM. Instead of continuing to throw parts at it, we hooked up our diagnostic scope. We found the injector pulse width signals coming from the PCM were erratic on multiple cylinders. The internal drivers were failing from years of heat and vibration. A new, correctly programmed PCM was the only solution, and it fixed the problem instantly.”
The Direct Solution: A VIN-Programmed PCM
This isn’t just a replacement part; it’s a complete solution. We are offering a Powertrain Control Module, part number 16263494, that is professionally programmed to your vehicle’s specific Vehicle Identification Number (VIN). This is the most critical step in the process. Without proper programming, the module simply will not work with your truck’s specific engine, transmission, and options.
Why Our Programming Service is a Game Changer
- ✔ Guaranteed Compatibility: By using your VIN, we load the exact GM-certified calibration file for your vehicle. This eliminates all guesswork.
- ✔ Latest Software Updates: We flash the module with the newest software available from General Motors. These updates often contain fixes for drivability issues, emissions performance, and transmission logic that your original module never had.
- ✔ Plug-and-Play Installation: Once you receive the module, the physical installation is straightforward. After it’s installed, you will need to perform a security relearn procedure (often called a Passlock or CASE relearn), which syncs the new PCM to your vehicle’s anti-theft system. This procedure is simple and can typically be done in your driveway without special tools.
- ✔ Restored Performance: A new, correctly functioning PCM will restore crisp shifting, stable engine idle, proper fuel delivery, and overall vehicle reliability.
How It Works & Verifying Your Fitment
The process is simple. After you purchase the module, you just need to send us your 17-digit VIN. Our technicians will handle the rest, ensuring the module that arrives at your door is ready for installation. This PCM is a direct replacement for service numbers 16263494, 16265035, and 8162634940, among others listed in the compatibility chart.
This module fits a very wide range of GM trucks, vans, and SUVs from roughly 1998 to 2002, including the Chevy Express, GMC Savana, Tahoe, Yukon, Silverado, Sierra, and more. Please check the detailed fitment list provided to see if your specific model is included. The most reliable way to ensure a perfect match is to confirm the part number on your original module or provide us with your VIN before ordering.