Restore Your Truck’s Brain and Get Back on the Road

There’s nothing more frustrating than a reliable truck that suddenly starts acting up. Whether you’re dealing with a persistent Check Engine Light, unpredictable stalling, or a complete no-start situation, the problem often points to a failing Powertrain Control Module (PCM). As the central computer of your vehicle, the PCM controls everything from fuel mixture and ignition timing to transmission shifting. When it fails, your truck’s performance and reliability suffer. This replacement PCM is the definitive solution, arriving at your door programmed with the latest GM software updates, specifically matched to your vehicle’s VIN.

Is Your Truck’s Computer Showing These Signs?

A faulty PCM can cause a wide range of symptoms. If you’re experiencing any of the following, this module is likely the solution you need. In my 20+ years of experience, these are the most common indicators of a failing computer in these GM trucks and vans.

• ✔ Persistent Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
• ✔ Engine stalling, stumbling, or running rough for no apparent reason.
• ✔ Vehicle refuses to start or has a hard time starting, even with a good battery and starter.
• ✔ Noticeably poor fuel economy and loss of power.
• ✔ Harsh or erratic automatic transmission shifting.
• ✔ Failure to pass state emissions testing.

DIY-Friendly Installation: A Straightforward Guide

You don’t need to be a master mechanic to install this part. Our VIN programming service makes this a true plug-and-play repair, saving you a costly trip to the dealership. Just follow these simple steps to get your 1999-2000 GMC 2500 PCM installed.

1. Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning any electrical work.
2. Locate the Old PCM: On most of these trucks, the PCM is located in the engine compartment on the driver’s side, often near the battery or firewall. It’s a silver metal box with several large electrical connectors.
3. Disconnect and Remove: Carefully unclip and remove all electrical connectors from the old module. Then, unbolt the module from its mounting bracket and remove it from the vehicle.
4. Install the New Module: Bolt your new, pre-programmed PCM into the mounting bracket. Firmly reconnect all electrical connectors, ensuring they click securely into place.
5. Reconnect and Start: Reconnect the negative battery terminal. The vehicle may require a security relearn or a Crankshaft Position Sensor (CASE) relearn, which can often be done with a capable scan tool or by following a specific drive cycle.

Verified Vehicle Compatibility

This module, service number 16265035, is a direct replacement for a wide range of GM vehicles. It is also compatible with part numbers 16263494, 8162634940, 218-11787, and 21811787. Please confirm your vehicle is on this list before ordering. Providing your VIN at checkout ensures we send you a perfectly matched and updated module.