If your GMC or Chevy truck is suffering from frustrating issues like a persistent check engine light, poor fuel mileage, erratic shifting, or a dreaded no-start condition, the problem often traces back to a failing Powertrain Control Module (PCM). As the central computer for your engine and transmission, a faulty PCM can cause a cascade of problems that are difficult to diagnose. I’ve spent countless hours in the shop tracing wires and running diagnostics, and a significant number of times on these late 90s/early 2000s GM trucks, the PCM itself is the culprit.
This isn’t just a replacement part; it’s a complete solution. We take the guesswork and the expensive trip to the dealership out of the equation. Each module is professionally flashed with the latest official GM software updates, specifically programmed to your vehicle’s unique Vehicle Identification Number (VIN). This ensures that all factory parameters for your engine, transmission, and emissions systems are perfectly calibrated. You get a reliable part that’s truly plug-and-play, restoring your truck’s original performance and dependability.
From the Diagnostic Bay
I remember a 2000 Silverado 1500 with the 4.3L V6 that came in on a tow truck. The owner said it would run fine for 15 minutes, then shut off and refuse to restart for an hour. No check engine light, no stored codes—a real head-scratcher. After checking fuel pressure and spark, which were fine when it was cold, I let it run in the bay until it stalled. The moment it died, I lost communication with the PCM on my scan tool. A few minutes with a heat gun pointed at the module confirmed my suspicion: the internal processor was failing under thermal stress. We installed a VIN-programmed module just like this one, and the truck has been running reliably ever since. These intermittent, heat-related failures are a classic symptom.
Is Your Truck Showing These Symptoms?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, it might be time to replace the brain of your truck’s operation. This 1999-2000 GMC 2500 PCM is the definitive fix for these common issues.
- ✔ Unexplained Check Engine Light (CEL)
- ✔ Stored diagnostic trouble codes (DTCs) like P0601, P0605, or U-series communication codes
- ✔ Engine cranks but will not start
- ✔ Rough or unstable idle
- ✔ Poor acceleration and loss of power
- ✔ Decreased fuel economy
- ✔ Harsh or incorrect transmission shifting
- ✔ Failure to pass state emissions testing
A Straightforward Guide to Installation
Installing your new PCM is a manageable job for a DIYer with basic tools. Our pre-programming service means you won’t need a high-end scan tool for setup.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- Locate the PCM: On most of these trucks and vans, the PCM is located in the engine compartment, typically on the driver’s side fender well or near the battery.
- Disconnect Connectors: Carefully release the locking tabs and unplug the wiring harness connectors from the old module. Inspect the connectors for any corrosion or damage.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s usually held in by a few small bolts.
- Install the New Module: Mount your new, pre-programmed PCM onto the bracket and securely fasten the bolts.
- Reconnect Everything: Plug the wiring harnesses back into the new module, ensuring they click securely into place. Reconnect the negative battery terminal.
- Security Relearn (If Necessary): In many cases, you may need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. This allows the new PCM to sync with your vehicle’s anti-theft system. Consult your owner’s manual for the specific procedure for your model.
Verified Vehicle Compatibility
This module, part number 16265035, is a direct replacement for service numbers 16263494, 8162634940, 218-11787, and 21811787. It is guaranteed to fit the following gasoline-engine models. Please provide your VIN upon purchase to ensure we send you a perfectly matched 1999-2000 GMC 2500 PCM or compatible module for your specific vehicle.
CHEVROLET 2500 PICKUP 99-00 (Gasoline, ID 16263494 for 99)
CHEVROLET 3500 PICKUP 99-00 (Gasoline, ID 16263494 for 99)
SIERRA/SILVERADO 1500 99-00 (4.3L V6)
GMC 1500 PICKUP 99 (5.0L/5.7L, ID 16263494)
GMC 2500 PICKUP 99-00 (Gasoline, ID 16263494 for 99)
GMC 3500 PICKUP 99-00 (Gasoline, ID 16263494 for 99)
TAHOE/YUKON 99-00 (Gasoline, Classic Style for 00)
SUBURBAN 1500/2500 99 (Gasoline, ID 16263494)
ESCALADE 99-00
ASTRO/SAFARI 99-01 (4.3L, ID 16263494)
BLAZER/JIMMY/BRAVADA 98-00 (w/ build date opt ZN4 for 98)
S10/SONOMA/HOMBRE 98-00 (4.3L, w/ build date opt ZN4 for 98)
ENVOY 98-00 (w/ build date opt ZN4 for 98)
EXPRESS/SAVANA 1500/2500/3500 99-02 (Gasoline, ID 16263494 on select models)
Frequently Asked Questions
Why do you need my VIN?
Your VIN (Vehicle Identification Number) allows us to program the PCM with the exact software and calibrations your specific truck requires. This includes details like engine size, transmission type, and axle ratio, ensuring perfect compatibility and performance right out of the box.
Is this part difficult to install?
No, this is a straightforward replacement. Since the module comes pre-programmed, you do not need special dealership tools. Basic hand tools are all that’s required for the physical swap. You may need to perform a simple security relearn procedure, which takes about 30 minutes.
What is the difference between a PCM and an ECM?
The terms are often used interchangeably. ECM stands for Engine Control Module, while PCM means Powertrain Control Module. A PCM is an ECM that also controls the transmission and other powertrain functions. For these GM vehicles, this unit is a PCM.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the original PCM (common codes P0601-P0606), then yes, this will resolve the issue. However, if the light is on due to a bad sensor or other component, that separate issue will still need to be addressed.
Is any other programming required after installation?
No. Our service covers the primary programming. The only potential step is the security relearn, which syncs the module to your truck’s anti-theft system. This procedure does not require any special tools.