Restore Peak Performance to Your GM Vehicle
Is your Chevrolet Astro, Express Van, or GMC Sierra suffering from frustrating issues like a persistent check engine light, erratic shifting, poor fuel mileage, or even a no-start condition? These are classic signs of a failing Powertrain Control Module (PCM). The PCM is the electronic brain of your vehicle, managing critical engine and transmission functions. When it fails, it can cause a cascade of problems that can leave you stranded. This replacement PCM, part number 8162634940, is the definitive solution to get your truck or van running reliably again.
The Plug-and-Play Solution for Your 1999-2001 Astro PCM
Forget expensive dealership visits and complicated programming procedures. We take the guesswork out of the repair. When you purchase this module, we will flash it with the latest official GM software updates specifically for your vehicle. All we need is your Vehicle Identification Number (VIN) at checkout. This ensures that when the part arrives, it is ready for immediate installation. It is programmed to match your vehicle’s original factory settings, including the anti-theft system (VATS/Passlock), ensuring a seamless and straightforward repair.
From the Diagnostic Bay
We had a 2000 Chevy Express 2500 work van come into the shop that had its owner chasing ghosts for weeks. The van would randomly stall at idle and had a harsh 1-2 shift. The owner had already replaced the throttle position sensor and the idle air control valve based on some forum advice, with no improvement. After hooking up our professional scan tool, we noticed intermittent data loss from the PCM. We swapped in a VIN-programmed module just like this one, and the van immediately ran like new. It’s a powerful reminder that the control module itself is often the root cause, not just the sensors it monitors.
Common Symptoms of a Failing GM PCM
- ✔ Persistent Check Engine Light (CEL) with various trouble codes.
- ✔ Engine stalling, stumbling, or misfiring.
- ✔ Harsh, delayed, or incorrect automatic transmission shifting.
- ✔ A noticeable decrease in fuel economy.
- ✔ The vehicle cranks but refuses to start.
- ✔ Communication errors when trying to use an OBD-II scanner.
- ✔ False sensor readings or multiple unrelated error codes appearing at once.
Guaranteed Compatibility and Simple Installation
This module is a direct replacement for multiple OEM part numbers, including 16263494, 16265035, and 8162634940. It fits a wide array of popular GM trucks and vans from the late 1990s and early 2000s, such as the Chevrolet Silverado, GMC Sierra, S10/Sonoma, Tahoe/Yukon, and many others equipped with the venerable 4.3L, 5.0L, and 5.7L gasoline engines. Please verify your part number or consult the detailed fitment list to ensure perfect compatibility.
Installation is straightforward for any DIY mechanic. Simply disconnect the battery, locate your existing PCM (often in the engine bay near the battery or on the fender), unplug the electrical connectors, unbolt the old unit, and install the new one in its place. Reconnect everything, and you’re ready to go. In some cases, a simple security relearn procedure, which involves cycling the key, may be necessary. This can be done in your driveway without any special tools.
Frequently Asked Questions
Do I need to program this module after I receive it?
No. This PCM arrives fully programmed to your vehicle’s specific VIN. It is a true plug-and-play solution, ready for installation right out of the box. No trip to the dealer is required.
Where do I provide my vehicle’s VIN?
After you complete your purchase, we will contact you to request your VIN. Alternatively, you can add your VIN to the notes section during checkout. We cannot ship the module until we have this information to program it correctly.
What is the difference between an ECM, PCM, and ECU?
These terms are often used interchangeably. ECU (Engine Control Unit) is a general term. ECM (Engine Control Module) typically controls only engine functions. A PCM (Powertrain Control Module) is more integrated and controls both the engine and the transmission, which is standard on most vehicles this part fits.
Will this fix my check engine light?
If the check engine light is on due to an internal failure of your existing PCM, then yes, this part will resolve the issue. It’s crucial to properly diagnose the problem first, as the light can also be triggered by faulty sensors or other components.
Is a security relearn procedure required?
While we program the module to your VIN to match the security system, some GM vehicles may require a simple key-cycle relearn procedure to sync the new PCM. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. Instructions are readily available online for your specific model.