Restore Your Vehicle’s Core Performance and Reliability
Is your Pontiac G8, Silverado, or another GM vehicle acting erratically? Experiencing frustrating issues like stalling, poor fuel economy, a persistent check engine light, or a no-start condition? The Engine Control Module (ECM), often called the vehicle’s brain, is responsible for managing dozens of critical functions. When it starts to fail, it can cause a cascade of problems that are often difficult to diagnose. As a technician with over two decades of experience, I’ve seen countless drivers spend a fortune chasing symptoms when the root cause was a failing ECM.
This replacement Engine Control Module, part number 12625455, is the definitive solution to get your vehicle running right again. We take the guesswork and extra cost out of the repair. Before we ship your part, we program it with the latest GM software updates, perfectly matched to your vehicle’s specific Vehicle Identification Number (VIN). This means no expensive trips to the dealership for programming. It arrives at your door ready for a straightforward installation, making it a perfect project for a skilled DIYer or a time-saving solution for a professional shop. By replacing your faulty unit with this pre-programmed 2009 G8 Engine Computer, you’re not just fixing a part; you’re restoring the precision, efficiency, and reliability your vehicle was designed to have.
From the Diagnostic Bay: The Intermittent Stall Case
I remember a 2009 Pontiac G8 GT that came into my shop with a problem that was driving the owner crazy. It would run perfectly for days, then suddenly stall at a red light and refuse to restart for 10-15 minutes. No consistent trouble codes were stored, just a few random communication errors that would clear themselves. We checked fuel pressure, ignition components, and wiring harnesses, but everything tested fine. After experiencing the stall myself and noticing the tachometer drop to zero instantly, my gut pointed to the ECM. On these vehicles, internal circuit board failures due to heat cycles can cause these exact phantom issues. We installed a VIN-programmed ECM, and the problem vanished. The owner was relieved to finally have a reliable car again, proving that a quality 2009 G8 Engine Computer is the key to solving these tough electrical gremlins.
Is Your Vehicle Showing These Symptoms?
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ The engine is stalling or hesitating intermittently.
- ✔ Rough idling or misfires.
- ✔ Automatic transmission shifting issues.
- ✔ Loss of communication with the diagnostic scan tool.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- ✔ Locate the ECM: On the 2009 Pontiac G8, the ECM is typically found in the engine compartment. For other models like the Silverado or Express Van, it’s usually on the driver’s side of the engine bay. Consult a repair manual if you’re unsure.
- ✔ Disconnect Connectors: Carefully unclip the wiring harness connectors from the old ECM. These connectors have locking tabs that need to be released before pulling. Do not force them.
- ✔ Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the mounting hardware as you will need it for the new unit.
- ✔ Install the New ECM: Mount your new, pre-programmed 2009 G8 Engine Computer in place using the original hardware.
- ✔ Reconnect Everything: Firmly plug the wiring harnesses into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Final Steps: Your vehicle may require a security relearn procedure (often called a Passlock or Passkey relearn), which typically involves cycling the key in the ignition. This can usually be done without special tools. Start the vehicle and check for proper operation.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 12625455 and 12629009 and fits a wide variety of GM cars, trucks, and vans. Please verify your vehicle’s model and options below. Providing your VIN at checkout is essential to ensure we send you a perfectly matched and programmed part.
SILVERADO/SIERRA 2500/3500 PICKUP 09-10 (LH front engine), 6.0L
SUBURBAN/YUKON XL 1500 09-10 (LH front engine)
SATURN VUE 10 (Electronic Control Module), 3.5L
CADILLAC ESCALADE, ESV, EXT 09-10 (LH front engine), 6.2L
PONTIAC G6 09 (LH front engine), 3.9L or 3.5L
HUMMER H2 09 (LH front engine)
CHEVROLET MALIBU 09 (Electronic Control Module), 3.5L
CHEVROLET AVALANCHE 1500 09-10 (LH front engine)
SIERRA/YUKON DENALI 09-10 (LH front engine)
SILVERADO/SIERRA 1500 PICKUP 09 (LH front engine), w/o hybrid, w/o 4.3L
SAVANA 2500/3500 VAN 09 (LH rear engine), 6.0L or 4.8L
CHEVROLET TAHOE/YUKON 09-10 (LH front engine), w/o hybrid
SUBURBAN/YUKON XL 2500 09-10 (LH front engine)
CORVETTE 09 (RH engine), Base model
PONTIAC G8 09 (Electronic Control Module), ID 12625455
CHEVROLET IMPALA 09 (lower air cleaner box), 3.9L or 3.5L
SAVANA/EXPRESS 1500 VAN 09 (LH rear engine), 5.3L
…and more. Please use our fitment checker or contact us with your VIN.
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming before shipping. We flash the module with the latest GM software updates using the VIN you provide, so it’s ready to install right out of the box.
Is this a simple DIY job?
For someone with basic mechanical skills, this is a very manageable job. The most important parts are being careful with the electrical connectors and performing the security relearn procedure, which doesn’t require special tools. Our installation guide provides the key steps.
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot ship your order until we receive this information.
Will this fix my check engine light?
If the check engine light is caused by an internal ECM failure (like codes P0601, P0606, etc.), then yes, this part will resolve the issue. It’s crucial to ensure the problem has been properly diagnosed, as other faulty sensors or wiring could also cause a check engine light.
What if I have a different part number on my old module?
This ECM, part number 12625455, also replaces part number 12629009. As long as your vehicle is on our compatibility list, this module will function correctly once programmed to your VIN.