Restore Peak Performance to Your GM Truck with a VIN-Programmed PCM
If you’re battling a persistent check engine light, erratic engine behavior, or frustrating transmission shifting in your 1999-2000 GMC 2500 or other compatible GM vehicle, the Powertrain Control Module (PCM) is often the root cause. As a technician with over two decades of experience, I’ve seen countless hours and dollars wasted on replacing perfectly good sensors when the vehicle’s ‘brain’ was the actual problem. This isn’t just a replacement part; it’s a direct solution, pre-programmed with the latest official GM software specifically for your vehicle’s VIN. This eliminates the need for an expensive trip to the dealership for programming.
This module acts as the central command for your engine and transmission, managing everything from fuel mixture and ignition timing to shift points and emissions controls. When it fails, it can create a cascade of confusing symptoms. Our process is simple: you provide your VIN at checkout, and we flash this module, ensuring it’s a true plug-and-play component ready for installation right out of the box. Restore the reliability and drivability you depend on with a dependable, correctly configured 1999-2000 GMC 2500 PCM.
From the Diagnostic Bay: The Ghost in the Machine
I remember a 2000 Chevy Express van that came into the shop with a complaint of intermittent stalling and a random misfire code that would pop up and disappear. The owner had already replaced the plugs, wires, cap, and rotor. He was frustrated. We checked fuel pressure, and scoped the ignition system—everything looked fine. On a hunch, I tapped on the PCM while the engine was running, and it immediately stumbled. The problem wasn’t a sensor or a wire; it was a hairline crack on the PCM’s internal circuit board. These units are subjected to years of heat and vibration, and internal failure is common. A replacement, VIN-programmed PCM solved the problem in under 30 minutes. This is a classic case where chasing symptoms can be a dead end, and addressing the core controller is the only real fix.
Is Your GM Truck or Van Showing These Signs?
A failing PCM can manifest in numerous ways. If you’re experiencing any of the following, this module is the likely solution:
- ✔ Check Engine Light is on with codes for internal module failure (e.g., P0601, P0606).
- ✔ Vehicle will not start or stalls intermittently.
- ✔ Poor or erratic automatic transmission shifting.
- ✔ A noticeable drop in fuel economy.
- ✔ Communication errors with scan tools (U-codes).
- ✔ Failure to pass an emissions test due to module-related faults.
- ✔ Engine runs rough, misfires, or hesitates for no apparent reason.
A Straightforward Guide to Installation
Installing your new 1999-2000 GMC 2500 PCM is a simple process that most DIYers can handle. Always consult a service manual for your specific vehicle’s location and torque specs.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, often on the driver’s side fender well or near the battery.
- Disconnect the Harnesses: Carefully unclip and remove the electrical wiring harnesses connected to the old module. The connectors have locking tabs that need to be released.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. Keep the hardware as you may need to reuse it.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and secure it.
- Reconnect Everything: Firmly plug the wiring harnesses into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Necessary): In some cases, a simple security relearn procedure is needed. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Your vehicle’s service manual will have the specific steps if required.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 16263494, 16265035, and 8162634940. It is guaranteed to fit the following vehicles (please verify your specific options):
- Astro/Safari (GMC): 1999-2001 (ID 16263494)
- Blazer S10/Jimmy S15/Envoy: 1998 (w/ opt ZN4), 1999-2000
- Bravada: 1998 (w/ opt ZN4), 1999-2000
- Chevrolet/GMC 1500 Pickup: 1999 (5.0L/5.7L, ID 16263494)
- Chevrolet/GMC 2500 Pickup: 1999 (Gas, ID 16263494), 2000 (Gas)
- Chevrolet/GMC 3500 Pickup: 1999 (Gas, ID 16263494), 2000 (Gas)
- Escalade: 1999-2000
- Express/Savana 1500 Van: 1999-2002 (ID 16263494)
- Express/Savana 2500 Van: 1999-2002 (Gas, ID 16263494)
- Express/Savana 3500 Van: 1999-2002 (Gas, ID 16263494)
- Isuzu Hombre: 1998 (4.3L, w/ opt ZN4), 1999-2000 (4.3L)
- S10/S15/Sonoma: 1998 (4.3L, w/ opt ZN4), 1999-2000 (4.3L)
- Sierra/Silverado 1500 Pickup: 1999-2000 (4.3L V6)
- Suburban 1500/2500: 1999 (Gas, ID 16263494)
- Tahoe/Yukon: 1999 (ID 16263494), 2000 (Classic/Denali)
Frequently Asked Questions about this 1999-2000 GMC 2500 PCM
Frequently Asked Questions
Do I need to do any programming myself?
No. This Powertrain Control Module comes fully programmed to your vehicle’s specific VIN. We handle all the flashing before it ships, so it’s ready for installation when you receive it.
What information do you need from me?
After your purchase, we will need your 17-digit Vehicle Identification Number (VIN). This is crucial for us to load the correct GM software and ensure perfect compatibility with your truck’s engine, transmission, and options.
Is this a simple plug-and-play installation?
Yes, for the vast majority of vehicles. Once you install the module and reconnect the battery, you’re ready to go. A small number of vehicles may require a simple key-cycle security relearn procedure, which does not require any special tools.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls the electronic solenoids in the transmission that manage shifting. If your hard or erratic shifting is caused by a faulty computer, this part is the correct solution.
How do I find my part number to confirm a match?
The part number is printed on a sticker on your original PCM. This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, and 21811787. However, our VIN programming ensures compatibility even if your number differs slightly.