Is Your GM Truck or Van Driving You Crazy?
If your 1999-2000 Chevrolet 3500 is suddenly stalling, shifting erratically, or refusing to start, the problem might not be a bad sensor or fuel pump. After 20+ years turning wrenches, I’ve seen countless cases where the Powertrain Control Module (PCM) is the real culprit. It’s the brain of your vehicle, and when it starts to fail, the symptoms can be confusing and intermittent, leading you down a rabbit hole of expensive, unnecessary repairs.
Common Symptoms of a Failing PCM on These GM Vehicles:
Over the years, I’ve diagnosed hundreds of these specific GM PCMs. The circuit boards are prone to failure from heat, vibration, and age. If you’re experiencing any of these, your PCM is the likely cause:
- โ Engine stalls for no reason, especially when warm.
- โ Harsh or delayed automatic transmission shifts.
- โ The check engine light is on with communication error codes (U-codes) or false sensor codes.
- โ Complete no-start condition, even with a good battery and starter.
- โ Poor fuel economy and a general lack of power.
- โ Inconsistent or erratic gauge behavior.
Expert Pro Tip: Check Your Grounds First!
Before you condemn your PCM, do yourself a favor and check the main engine and chassis ground connections. On these GM trucks and vans, a corroded or loose ground strap can mimic PCM failure by causing voltage drops and communication errors. I’ve seen this save customers hundreds of dollars. A simple check near the battery, on the engine block, and to the frame can rule out the easy stuff first. If the grounds are clean and tight and the problems persist, the module itself is the next logical step.
The Direct, Reliable Solution: A VIN-Programmed PCM
Don’t waste time and money with a junkyard module that could have the same issues or require expensive dealership programming. We offer a straightforward solution. This Powertrain Control Module is rigorously tested and then programmed specifically to your vehicle’s 17-digit Vehicle Identification Number (VIN). This isn’t a generic, one-size-fits-all part; it’s tailored for your truck’s exact configuration.
What VIN Programming Means For You:
- โ No Dealership Visit Required: We load the latest, most stable software from GM directly onto the module before it ships.
- โ Guaranteed Compatibility: Programming to your VIN ensures the PCM works correctly with your specific engine, transmission, and emissions equipment.
- โ Plug-and-Play Installation: In most cases, installation is as simple as disconnecting the battery, swapping the module, and reconnecting the battery.
Installation and Important Notes
Locating your PCM can vary depending on your model. It’s typically found in the engine compartment, either on the driver’s side fender, under the battery tray, or on the passenger side firewall. The swap involves disconnecting a few electrical connectors and removing a couple of bolts.
IMPORTANT: After installation, some vehicles may require a security relearn procedure (often called Passlock or CASE relearn) to sync the new PCM with your vehicle’s anti-theft system. This is a simple procedure that you can typically perform yourself in about 30 minutes with just your ignition key. We can provide instructions for this process.
Confirm Your Part Number
This module is a direct replacement for several part numbers. Please verify that your original module has one of the following numbers printed on its label to ensure a perfect match:
- โ 16263494
- โ 16265035
- โ 8162634940
- โ 218-11787
- โ 21811787
Ordering is simple. Just complete your purchase and send us a message with your VIN. We’ll handle the programming and get your truck back on the road fast.