Is Your GM Truck or Van Acting Up? The Brain Might Be the Problem.
If you’re driving a workhorse like a 1999-2002 Chevrolet Express 2500, or a similar GM truck from that era, you count on it to start every time and run without drama. But after two decades of service, the electronic heart of your vehicleโthe Powertrain Control Module (PCM)โcan start to show its age. You might be experiencing frustrating issues that seem to come out of nowhere, leaving you stranded or dealing with a poorly running engine.
Over my 20+ years in the shop, I’ve seen hundreds of these specific GM PCMs fail. The symptoms are often confusing and can mimic other problems, leading to expensive and unnecessary repairs. Before you start replacing sensors and fuel pumps, it’s critical to consider the PCM.
Common Symptoms of a Failing GM PCM
A failing PCM doesn’t always result in a simple “no-start” condition. The signs can be subtle at first and gradually get worse. If your vehicle is showing any of these behaviors, its computer could be the culprit:
- โ Unexplained Check Engine Light with various communication or sensor codes.
- โ Harsh or erratic automatic transmission shifting, especially a hard 1-2 shift.
- โ Engine stalling for no reason, either at idle or while driving.
- โ A complete no-start condition where the engine cranks but won’t fire up.
- โ Loss of communication with your scan tool (U-codes are a big red flag).
- โ Poor fuel economy or a noticeable drop in engine power.
- โ The security or anti-theft light staying on, preventing the engine from starting.
๐ก Expert Pro Tip: Check Your Grounds First!
Before you condemn the PCM, do a voltage drop test on the main power and ground circuits going to the module. On these GM trucks and vans, a corroded ground strap on the frame or engine block can cause all sorts of bizarre electrical gremlins that look exactly like a bad PCM. I’ve saved customers hundreds of dollars by finding a bad $10 ground cable. A quick check can confirm you’re replacing the right part.
The Direct-Fit, Programmed Solution
This isn’t just a replacement part; it’s a complete solution. We take a quality, tested Powertrain Control Module and program it specifically for YOUR vehicle using the VIN you provide. This is a critical step that many sellers skip. Without proper programming, the module won’t communicate with the other systems in your truck, like the instrument cluster or the anti-theft system.
Hereโs what our service includes:
- โ VIN-Specific Programming: We flash the module with the latest GM-authorized calibration for your exact vehicle. This ensures all systems function correctly and can even resolve some factory drivability bugs.
- โ Plug-and-Play Design: Because it’s pre-programmed, installation is straightforward. In most cases, you simply disconnect the battery, swap the modules, and reconnect. A security relearn procedure may be necessary, which can often be done without special tools.
- โ Guaranteed Compatibility: This module is a direct replacement for a wide range of popular GM vehicles and is compatible with multiple part numbers.
Will This Fit My Vehicle?
This PCM is a direct replacement for units with part numbers 16263494, 16265035, and 8162634940. It fits a huge variety of GM trucks and vans from the late 90s and early 2000s, including:
- โ Chevrolet Express & GMC Savana Vans (1500, 2500, 3500)
- โ Chevrolet Silverado & GMC Sierra Pickups (1500, 2500, 3500)
- โ Chevrolet S10 / GMC Sonoma / Isuzu Hombre
- โ Chevrolet Blazer / GMC Jimmy / Oldsmobile Bravada
- โ Chevrolet Astro / GMC Safari Vans
- โ Chevrolet Tahoe / GMC Yukon / Cadillac Escalade
Please use the detailed fitment list to confirm your specific year, model, and engine combination. Finding the module on your vehicle is key; on Express/Savana vans it’s typically in the LH rear of the engine compartment, while on pickups and SUVs it’s often on the LH side near the fender or under the battery tray. Verifying your original part number is the best way to ensure a perfect match.