Restore Peak Performance to Your GM Truck or Car
Is your 1999-2000 GMC Sierra 2500, Chevrolet Silverado, or other compatible GM vehicle suffering from frustrating and unpredictable issues? Problems like a persistent Check Engine Light, erratic engine behavior, poor fuel economy, or harsh transmission shifting can often be traced back to a single, critical component: the Powertrain Control Module (PCM). As the central computer of your vehicle, the PCM is responsible for managing everything from fuel injection and ignition timing to transmission shift points and emissions controls. When it begins to fail, the symptoms can be widespread and difficult to diagnose.
This replacement Powertrain Control Module, part number 09354896 (also interchangeable with 19109040), is the definitive solution to get your vehicle running reliably again. We take the guesswork and hassle out of the repair process. Unlike a generic, off-the-shelf unit that requires an expensive trip to the dealership for programming, this module is professionally flashed with the latest official GM software updates specifically for your vehicle. All we need is your Vehicle Identification Number (VIN) at the time of purchase to ensure a perfect match, making the installation process as straightforward as possible.
From the Diagnostic Bay
We had a 2000 Silverado 2500 come into the shop with a ghost of a problem. The owner complained of intermittent stalling at stoplights, but it would always start right back up. There were no consistent trouble codes, just a random P0300 (Random/Multiple Cylinder Misfire Detected) that would pop up every few weeks. We checked plugs, wires, coils, and fuel pressure—all were within spec. After hours of chasing our tails, we monitored the live data from the PCM and noticed the ignition control signal would momentarily drop out right before a stall. We swapped in a known-good, programmed PCM, and the problem vanished. The original unit had an internal fault that only appeared under specific thermal conditions. It’s a classic example of how a failing PCM can create symptoms that mimic a dozen other issues.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) with various trouble codes, especially communication or internal processor codes.
- ✔ Engine stalling, stumbling, or hesitating during acceleration.
- ✔ Rough or erratic idling.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Harsh, delayed, or incorrect automatic transmission shifting.
- ✔ Failure to pass emissions testing.
- ✔ Complete no-start condition where the engine cranks but will not fire.
- ✔ Inconsistent or non-functional gauges on the instrument cluster.
The Direct Solution: A VIN-Programmed 1999-2000 Sierra 2500 PCM
The key to a successful and lasting repair is ensuring the replacement module is correctly calibrated for your vehicle’s specific configuration. The 1999-2000 Sierra 2500 PCM and its counterparts in other GM models are not one-size-fits-all. Factors like engine size, transmission type, gear ratios, and even tire size are all stored within the PCM’s software. By providing your VIN, you guarantee that the unit you receive is loaded with the precise factory programming your truck needs to operate as it was designed. This eliminates compatibility conflicts and ensures all related vehicle systems communicate correctly, restoring lost power, efficiency, and drivability.
Installation and Setup
For most of the trucks listed, including the Sierra and Silverado, the PCM is located in the engine bay on the driver’s side, typically under or near the battery tray. Installation is straightforward for a seasoned DIYer or any professional technician:
- Disconnect the Battery: Always disconnect the negative battery terminal before working on any electronic components.
- Locate and Remove the Old PCM: Unplug the large wiring harness connectors (they have locking tabs) and unbolt the module from its mounting bracket.
- Install the New PCM: Bolt the new module in place and securely reconnect the wiring harnesses. Ensure they click into place.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn Procedure: After installation, you may need to perform a security relearn procedure (often called a CASE relearn or Passlock relearn) to allow the vehicle to start. This procedure typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. Consult your vehicle’s service manual for the exact steps.
By choosing our pre-programmed module, you bypass the most complex and costly part of the job—the dealership programming. This is the most efficient way to replace a faulty 1999-2000 Sierra 2500 PCM and get back on the road with confidence.
Frequently Asked Questions
What does ‘VIN Programmed’ mean?
It means we load the module with the specific factory software for your exact vehicle using your 17-digit Vehicle Identification Number (VIN). This ensures the PCM works perfectly with your engine, transmission, and other options, just like the original part from the factory.
Is this part truly plug-and-play?
For most vehicles, yes. Once programmed to your VIN, it is ready for installation. However, many GM vehicles of this era require a security relearn procedure after installation to sync the new PCM with the vehicle’s anti-theft system. This is a simple procedure you can do yourself with just the ignition key.
Where is the PCM located on my 1999 Sierra 2500?
On the 1999-2000 Sierra and Silverado 2500 pickups, the PCM is located in the engine compartment on the driver’s side, mounted to a bracket underneath the battery tray.
What happens if I don’t provide my VIN?
We cannot ship the module without your VIN. The programming is essential for the part to function in your vehicle. After your purchase, please send us your VIN so we can prepare and ship your order promptly.
Will this fix my specific problem?
This module is a direct replacement for a faulty PCM and will resolve issues caused by a failing computer. While the symptoms listed are very common for PCM failure, we always recommend a proper diagnosis by a qualified mechanic to confirm the PCM is the root cause of your problem before ordering.