Is Your GM Truck or Van Plagued by Mysterious Electrical Gremlins?
If you’re driving a late 90s or early 2000s GM vehicle like a Savana, Express, Silverado, or S10, you know they’re built to work. But when the Powertrain Control Module (PCM) starts to fail, it can feel like the vehicle is possessed. One day it runs fine, the next it won’t start, stalls at a red light, or the transmission shifts erratically for no apparent reason. As a technician with over two decades of experience, I’ve seen these exact issues hundreds of times, and the root cause is often a failing PCM.
The original PCMs from this era, especially the ‘black box’ style like this 16263494, are prone to failure from years of heat cycles and engine vibration. The delicate internal circuits and solder points can develop microscopic cracks, leading to intermittent connections that drive owners and mechanics crazy trying to diagnose.
Common Symptoms of a Failing 16263494 PCM
A faulty PCM doesn’t always fail completely. It often starts with intermittent problems that are impossible to replicate consistently. If you’re experiencing any of the following, your PCM is the likely culprit:
- โ Check Engine Light is on with various, seemingly unrelated trouble codes.
- โ The engine cranks but refuses to start (no-start condition).
- โ Unexplained stalling, either while driving or at an idle.
- โ Harsh or erratic automatic transmission shifting.
- โ Poor fuel economy and a noticeable loss of power.
- โ Communication errors when trying to connect a scan tool.
- โ The anti-theft or security light stays on, preventing the engine from starting.
Expert Pro Tip: The 5-Volt Reference Test
Before condemning your PCM, here’s a quick test I do in my shop. A failing PCM often shorts the 5-volt reference circuit it supplies to critical sensors. Unplug your Throttle Position Sensor (TPS) or Manifold Absolute Pressure (MAP) sensor. With the key on (engine off), use a multimeter to test the reference wire (often gray on these models). You should see a steady 5 volts. If it’s low (e.g., 2.3V) or zero, and it returns to 5V when the sensor is unplugged, the sensor is bad. But if the voltage is low or non-existent at the PCM connector itself, the PCM’s internal regulator has likely failed. This test has saved me countless hours of guesswork.
The Direct-Fit, Programmed Solution
This isn’t just a replacement part; it’s a complete solution. We take a fully tested, reliable PCM and program it specifically for YOUR vehicle using the VIN you provide. This critical step ensures all systems operate exactly as the manufacturer intended. We load the latest GM-certified software, which often includes fixes for drivability issues that were discovered after your vehicle left the factory.
What this means for you:
- โ No Dealer Visit Required: You avoid the hassle and high cost of having a dealership program the module. Most shops and DIY mechanics don’t have the expensive tools (like a GM Tech 2) required for this job.
- โ VIN-Specific Programming: We ensure the software matches your engine, transmission, tire size, and other factory options for seamless performance.
- โ Security Relearn Ready: While this module comes programmed, your vehicle’s anti-theft system will likely need to perform a simple ‘relearn’ procedure. This can typically be done in your driveway without any special tools and takes about 30 minutes. We can provide instructions for this simple key-cycling process.
Verify Your Part Number
To guarantee a perfect match, please verify that your original module has one of the following part numbers printed on its label. This module is a direct replacement for:
- โ 16263494
- โ 16265035
- โ 8162634940
- โ 218-11787
- โ 21811787
Ordering is simple. After purchase, just send us a message with your vehicle’s 17-digit VIN, and we’ll handle the programming. This ensures you get a part that’s ready to install right out of the box, getting your trusted truck or van back on the road where it belongs.