Programmed 2009 G8 Engine Computer | ECM ECU PCM | 12629009

### Programmed 2009 G8 Engine Computer \| ECM ECU PCM \| 12629009   ## Restore Your Vehicle’s Brain and Get Back on the Road Is your Pontiac G8, or another GM vehicle, acting possessed? Unexplained stalling, a persistent check engine light, or a complete no-start situation can be incredibly frustrating. As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Engine Control Module (ECM) can cause a cascade of baffling problems. The ECM is the central computer of your vehicle, managing everything from fuel injection and ignition timing to transmission shifts. When it fails, your vehicle’s performance, reliability, and fuel economy suffer dramatically. This isn’t just a replacement part; it’s a direct solution. We offer a reliable, fully tested **2009 G8 Engine Computer** (also known as an ECU or PCM) that arrives at your door programmed and ready for installation. Simply provide us with your vehicle’s VIN during checkout, and our experts will flash the module with the latest GM-certified software specific to your car or truck. This crucial step eliminates the need for an expensive trip to the dealership, saving you both time and money. You are getting a direct-fit component that restores the precise operational parameters your vehicle had when it left the factory. #### A Technician’s Notebook: The Silverado That Wouldn’t Communicate I remember a 2009 Silverado 6.0L that came into my bay with a list of complaints as long as my arm: intermittent stalling at lights, erratic gauge behavior, and a transmission that shifted harshly. The owner had already replaced the battery and alternator. My scan tool kept showing a U0100 ‘Lost Communication with ECM’ code. After verifying the power and ground circuits to the module were solid—a critical first step many people skip—I knew the ECM itself was the culprit. The internal processor was failing intermittently. We installed a VIN-programmed module just like this one. The communication codes vanished, the engine ran smoothly, and the transmission shifted like new. It’s a classic case where shotgunning parts costs more than proper diagnosis and a quality replacement. ## Is Your GM Vehicle Showing These Symptoms? A faulty ECM can manifest in many ways. If you’re experiencing any of the following, it’s a strong indicator that your engine computer may need replacement: - ✔ Check Engine Light is on with communication or internal module codes (e.g., P0601, P0606, U0100). - ✔ Engine cranks but refuses to start. - ✔ Rough idling, stalling, or hesitation during acceleration. - ✔ Noticeable decrease in fuel efficiency. - ✔ Harsh or erratic automatic transmission shifting. - ✔ Misfire codes that persist even after replacing spark plugs and coils. - ✔ Apparent loss of power and poor overall performance. ## A Straightforward Guide to Your ECM Installation Installing your new **2009 G8 Engine Computer** is a manageable job for a confident DIYer. While specific locations vary by model (e.g., left front engine compartment on a Sierra vs. under the airbox on an Impala), the general process is similar. Always consult a service manual for your specific vehicle. 1. **Safety First:** Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection. 2. **Locate the ECM:** Find the existing Engine Control Module. On most GM trucks and SUVs from this era, it’s on the driver’s side of the engine bay, near the firewall or fender. 3. **Disconnect Connectors:** Carefully release the locking tabs and unplug all wiring harness connectors from the old module. Inspect the connectors for any corrosion or damage. 4. **Remove the Old Module:** Unbolt the old ECM from its mounting bracket. Keep the hardware as you may need to reuse it. 5. **Install the New Module:** Bolt the new, pre-programmed ECM into place. 6. **Reconnect Everything:** Firmly plug the wiring harnesses into the new module until they click into place. Reconnect the negative battery terminal. 7. **Final Steps:** Depending on your vehicle, a security relearn procedure may be necessary. This can often be done without special tools by cycling the key. Turn the key to ‘ON’ for 10-15 minutes, then ‘OFF’ for 30 seconds, and repeat three times before attempting to start the engine. ## Verified Vehicle Compatibility List This module, part number **12629009** (interchangeable with **12625455**), is a direct-fit replacement for a wide range of General Motors vehicles. Please verify your specific model and options below to ensure proper fitment. AVALANCHE 1500 09 Electronic Control Module; (LH front engine compartment) AVALANCHE 1500 10 Electronic Control Module; (LH front engine compartment), ID **12625455** CORVETTE 09 Electronic Control Module; (RH engine compartment), Base ESCALADE 09 Electronic Control Module; (LH front engine compartment), 6.2L ESCALADE 10 Electronic Control Module; (LH front engine compartment), 6.2L, ID **12625455** ESCALADE ESV 09 Electronic Control Module; (LH front engine compartment) ESCALADE ESV 10 Electronic Control Module; (LH front engine compartment), ID **12625455** ESCALADE EXT 09 Electronic Control Module; (LH front engine compartment) ESCALADE EXT 10 Electronic Control Module; (LH front engine compartment), ID **12625455** EXPRESS 1500 VAN 09 Electronic Control Module; (LH rear engine compartment), 5.3L EXPRESS 2500 VAN 09 Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L EXPRESS 3500 VAN 09 Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L G6 09 Electronic Control Module; (LH front engine compartment), 3.5L or 3.9L G8 09 Electronic Control Module; ID **12625455** HUMMER H2 09 Electronic Control Module; (LH front engine compartment) IMPALA 09 Electronic Control Module; (lower part of air cleaner box), 3.5L or 3.9L MALIBU 09 Electronic Control Module; 3.5L SAVANA 1500 VAN 09 Electronic Control Module; (LH rear engine compartment), 5.3L SAVANA 2500 VAN 09 Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L SAVANA 3500 VAN 09 Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L SIERRA 1500 PICKUP 09 Electronic Control Module; (LH front engine compartment), w/o hybrid option; w/o 4.3L SIERRA 2500 PICKUP 09-10 Electronic Control Module; (LH front engine compartment), 6.0L SIERRA 3500 PICKUP 09-10 Electronic Control Module; (LH front engine compartment), 6.0L SIERRA DENALI 09-10 Electronic Control Module; (LH front engine compartment) SILVERADO 1500 PICKUP 09 Electronic Control Module; (LH front engine compartment), w/o hybrid option; w/o 4.3L SILVERADO 2500 PICKUP 09-10 Electronic Control Module; (LH front engine compartment), 6.0L SILVERADO 3500 PICKUP 09-10 Electronic Control Module; (LH front engine compartment), 6.0L SUBURBAN 1500 09 Electronic Control Module; (LH front engine compartment) SUBURBAN 1500 10 Electronic Control Module; (LH front engine compartment), ID **12625455** SUBURBAN 2500 09 Electronic Control Module; (LH front engine compartment) SUBURBAN 2500 10 Electronic Control Module; (LH front engine compartment), ID **12625455** TAHOE 09 Electronic Control Module; (LH front engine compartment), w/o hybrid option TAHOE 10 Electronic Control Module; (LH front engine compartment), w/o hybrid option; ID **12625455** VUE 10 Electronic Control Module; 3.5L YUKON 09 Electronic Control Module; (LH front engine compartment), w/o hybrid option YUKON 10 Electronic Control Module; (LH front engine compartment), w/o hybrid option; ID **12625455** YUKON XL 1500 09 Electronic Control Module; (LH front engine compartment) YUKON XL 2500 09 Electronic Control Module; (LH front engine compartment) YUKON XL 2500 10 Electronic Control Module; (LH front engine compartment), ID **12625455** ## Frequently Asked Questions ### Frequently Asked Questions **Do I need to do any programming myself?** No. This module is delivered to you pre-programmed with the latest GM software using the VIN you provide. This makes the installation process much simpler and avoids a costly dealer visit. **Is this part difficult to install?** For someone with moderate mechanical skill, it’s a very manageable job. It typically involves disconnecting the battery, unplugging the old module, unbolting it, and reversing the process with the new one. A security relearn procedure may be required, which usually doesn’t need special tools. **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 Vehicle Identification Number (VIN). We cannot ship the part until we have this information to program it correctly. **Will this fix my check engine light?** If the check engine light is caused by an internal failure of the ECM (common codes P0601-P0606) or a communication fault (U-codes), then yes, this part is the correct fix. It’s always best to have the codes professionally diagnosed to confirm the ECM is the root cause. **Is this compatible with part number 12625455?** Yes, this ECM, part number **12629009**, is a fully compatible and interchangeable replacement for part number **12625455**. Please enter it in the payment notes and save to ensure we receive it. Orders without a VIN within our 2-business-day handling period may be canceled, as programming cannot proceed without it. ### Shipping - **Processing Time:** Reliably shipped within 2-3 business days. ### Warranty Enjoy peace of mind with a **one-year replacement warranty** on this part, effective from the date you receive it. Labor costs are not covered. If the part fails within the warranty period, we’ll replace it with a comparable unit or refund your purchase price, ensuring a hassle-free experience. **Return Address:** **Highway71autoparts** **9131 Highway 71 NE** **Spicer, MN, 56288**

• Manufacturer Part Number: 12629009
• Country/Region of Manufacture: United States
• Manufacturer Warranty: 1 Year
• Superseded Part Number: 12629009
• Brand: GM
• Year: 2009
• Model: G8
• Hardware Type: E38
• Genuine OEM: Yes
• Interchange Part Number: 590-01527
• PartNumber: 590
• MPN: 12625455 12629009