Restore Peak Performance to Your GM Vehicle
Is your truck or car running rough, throwing confusing check engine codes, or refusing to start? The Powertrain Control Module (PCM), often called the engine’s brain, is responsible for managing everything from fuel mixture and ignition timing to transmission shifting. When it fails, it can cause a wide range of frustrating and difficult-to-diagnose issues. This genuine OEM replacement PCM, service number 12629019, is the definitive solution to get your vehicle back on the road and running like new.
From the Diagnostic Bay
We had a 2008 Sierra 1500 in the shop that was driving the owner crazy. It had an intermittent no-start condition, a random misfire on cylinder 3, and the transmission would occasionally shift hard into second gear. The check engine light was on, but the codes were all over the place. We checked the wiring, sensors, and fuel system, and everything seemed fine. After hours of diagnostics, we traced the issue to a failing PCM. The internal circuits were breaking down when warm, causing erratic signals to be sent throughout the vehicle. We installed a VIN-programmed PCM just like this one, performed the security relearn, and the truck has run flawlessly ever since. It’s a perfect example of how one single component can create a cascade of seemingly unrelated problems.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) with various or inconsistent codes.
- ✔ Engine stalling, stumbling, or misfiring.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Complete no-start or intermittent starting problems.
- ✔ Failure to communicate with a diagnostic scan tool.
- ✔ Other warning lights on the dashboard, like traction control.
Your Direct-Fit 2007-2009 Sierra PCM Solution
Don’t settle for a generic, one-size-fits-all module. We take the guesswork out of the repair by pre-programming this PCM specifically for your vehicle using your VIN. This ensures that it has the correct software, calibrations, and the latest updates directly from GM for optimal performance and compatibility. It’s a direct replacement for multiple service numbers, including 12597125, 12612397, 12635902, and more, making it a versatile solution for a wide range of GM cars, trucks, and vans.
Upon purchase, simply provide us with your vehicle’s VIN. Our technicians will flash the module, so it’s ready for installation right out of the box. While the programming is done for you, please be aware that a security relearn procedure (often called a Passlock or anti-theft relearn) may be required after installation. This is a standard procedure that can often be done without special tools and ensures the new PCM communicates with your vehicle’s anti-theft system.
Frequently Asked Questions
What is a PCM and what does it do?
The Powertrain Control Module (PCM) is the primary computer in your vehicle that controls all aspects of the engine and transmission. It reads data from dozens of sensors to manage fuel injection, spark timing, emissions systems, and transmission shift points to ensure optimal performance, fuel efficiency, and low emissions.
Do I need to program this PCM?
No, we handle the programming for you before we ship it. You must provide your vehicle’s 17-digit VIN at checkout so we can load the correct GM-certified software and calibrations for your specific make, model, and options.
Where is the PCM located on my 2007-2009 Sierra 1500?
On the 2007-2009 GMC Sierra and Chevrolet Silverado 1500, the PCM is typically located in the engine bay on the driver’s side, underneath the battery tray. Always disconnect the battery before attempting to access or replace the module.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM, then yes, this part will resolve the issue. However, it’s crucial to properly diagnose the vehicle first, as the check engine light can be triggered by many other components, such as a bad sensor or a wiring issue.
What is a security relearn and will I need to do one?
A security relearn, or anti-theft relearn, is a procedure that syncs the new PCM with your vehicle’s existing keys and anti-theft system. Most GM vehicles of this era require this procedure after a PCM replacement. It can often be performed by the owner with a simple key-cycling process, which takes about 30 minutes. Instructions are widely available online for your specific model.