1999 GMC 1500 PCM Powertrain Control Module 16263494 | VIN Programmed

Is your trusty GM truck or van suddenly running rough, shifting erratically, or refusing to start? Before you start throwing expensive parts at it, the problem might be its electronic brain: the Powertrain Control Module (PCM). As a technician with over two decades of experience, I’ve seen countless vehicles sidelined by a failing PCM. It’s the central command for your engine and transmission, and when it goes, it can cause a host of frustrating and hard-to-diagnose issues. This isn’t just a part; it’s the solution to getting your vehicle’s reliability and performance back to factory standards.

This Powertrain Control Module, part number 16263494, is a direct-fit replacement for a wide range of GM vehicles. The best part? We take the biggest headache out of the equation. Forget about expensive dealership visits or needing specialized scan tools for programming. We flash this module with the latest GM software updates, specifically programmed to your vehicle’s VIN before it even leaves our facility. This ensures a seamless, plug-and-play installation that restores proper communication between all your vehicle’s critical systems.

Is Your Truck or Van Showing These Signs?

A faulty PCM can manifest in ways that often mimic other failing components. If you’re experiencing any of the following, a failing computer is a likely culprit. I’ve seen these symptoms hundreds of times in my shop, often leading to a definitive 1999 GMC 1500 PCM replacement.

• ✔ Persistent Check Engine Light with codes like P0601 (Internal Control Module Memory Check Sum Error) or other U-series communication codes.
• ✔ Unexplained drops in fuel economy.
• ✔ Rough or unstable idle, and stalling for no apparent reason.
• ✔ Harsh or delayed transmission shifting.
• ✔ Engine cranks but refuses to start (no-start condition).
• ✔ Failure to pass state emissions testing.
• ✔ Seemingly random electrical issues or warning lights.

Straightforward Installation to Get You Running

You don’t need to be a master mechanic to install this module. With our pre-programming service, the most complex part is already done. Just follow these simple steps.

1. Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system capacitors to discharge.
2. Locate the Old PCM: On most trucks and vans on the fitment list, the PCM is located in the engine compartment, either on the driver’s side inner fender, under the battery tray, or on the passenger’s side firewall.
3. Disconnect the Connectors: Carefully unclip the wiring harness connectors from the old module. They have locking tabs, so be gentle to avoid breaking them. Inspect the connectors for any corrosion or bent pins.
4. Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s typically held on by a few small bolts.
5. Install the New Module: Mount your new, VIN-programmed PCM onto the bracket and securely bolt it in place.
6. Reconnect Everything: Firmly plug the wiring harnesses into the new module until they click. Reconnect the negative battery terminal.
7. Perform Security Relearn (If Necessary): While often not required, some GM vehicles may need a simple key-cycle security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your vehicle’s service information if needed.

Verified Vehicle Compatibility List

This module is a direct replacement for part numbers 16263494, 16265035, 8162634940, 218-11787, and 21811787. It is guaranteed to fit the following vehicles and configurations. Please match your part number or vehicle to ensure correct fitment.