Restore Your Truck’s Heartbeat and Drive with Confidence
Is your Sierra 1500 running rough, stalling unexpectedly, or flashing a persistent check engine light? These frustrating issues often point to a failing Powertrain Control Module (PCM), the central computer of your vehicle. Don’t let a faulty module keep you off the road. This replacement PCM, service number 12635902, is the definitive solution to bring back the smooth performance and unwavering reliability you depend on. We take the guesswork and dealer-level complexity out of the equation by programming the unit specifically to your truck’s Vehicle Identification Number (VIN) before it even leaves our facility. This means you get a component that is truly ready to install right out of the box, saving you time, money, and the headache of a tow to the dealership.
Warning Signs and How to Overcome Them
A failing PCM can manifest in a variety of confusing ways. If you’re experiencing any of the following, this pre-programmed module is your solution:
- ✔ Unexplained stalling or engine hesitation.
- ✔ Rough idling or poor engine performance.
- ✔ Difficulty starting the engine or a complete no-start condition.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Decreased fuel economy for no apparent reason.
- ✔ Diagnostic Trouble Codes (DTCs) such as P0601, P0606, or U0100 (Lost Communication with ECM/PCM).
- ✔ The constant worry of a check engine light that won’t go away.
From a Frustrated Owner to a Confident Driver
“I was at my wit’s end. My ’08 Sierra would just die at stoplights, completely random. My local shop replaced sensors, checked wiring… nothing worked. I was starting to think I’d have to sell the truck. I ordered this programmed PCM as a last resort. It arrived quickly, I swapped it out in about 45 minutes, and it fired right up. The idle was smoother than it’s been in years. Two months later, not a single stall. It’s like having my old, reliable truck back. That peace of mind is priceless.”
Guided Installation for a Lasting Repair
You don’t need to be a master mechanic to complete this job. With basic hand tools and a little patience, you can restore your vehicle’s performance. Follow these steps for a successful installation:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the PCM: On your Sierra 1500, the PCM is typically located in the engine bay, on the driver’s side, underneath the battery tray. You will need to remove the battery to access it.
- Disconnect the Harnesses: Carefully disengage the locking tabs on the electrical connectors and pull them straight out from the old module. Inspect the connectors for any corrosion or damage.
- Swap the Modules: Unbolt the old PCM from its mounting bracket. Install your new, pre-programmed 2007-2009 Sierra 1500 PCM in its place and secure it.
- Reconnect and Power Up: Firmly plug the electrical harnesses into the new module until they click into place. Reinstall and reconnect the battery.
- Final Step – Security Relearn: Your vehicle’s anti-theft system will need to sync with the new PCM. This is a simple procedure: Turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds. Repeat this cycle 2-3 times. Your truck should then start and run smoothly. In some cases, a Crankshaft Position Variation Relearn may be needed with a scan tool for optimal performance.
Tailored Fit for Your GM Vehicle
While this is a perfect solution for the 2007-2009 Sierra 1500 PCM, this versatile module is also a direct-fit, pre-programmed solution for a wide range of other GM cars, trucks, and vans. Please verify your service number (found on the original module’s sticker) matches one of the following: 12612397, 126140, 12594750, 12597125, 12629019, 12635902, 12611549. This unit is compatible with models including:
- Chevrolet Silverado 1500 (2007-2009)
- Chevrolet Malibu (2007-2012)
- Chevrolet Express 1500 Van (2008-2009)
- Chevrolet Cobalt (2007-2010)
- Chevrolet HHR (2007-2011)
- Chevrolet Impala (2010-2011)
- GMC Savana 1500 Van (2008-2009)
- Buick Lucerne (2009-2011)
- Saturn Aura (2008-2009)
- Saturn Vue (2008-2010)
- Pontiac G6 (2008-2010)
- Pontiac Solstice (2008-2010)
- Pontiac G5 (2007-2010)
- Saturn Sky (2008-2010)
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming for you. Simply provide your vehicle’s VIN during checkout, and we will flash the module with the latest GM-certified software specific to your vehicle’s configuration before shipping.
What is a ‘Security Relearn’ and is it difficult?
The security relearn is a simple process that syncs the new PCM with your vehicle’s anti-theft system. It typically involves cycling the ignition key and waiting for about 10-15 minutes per cycle. It requires no special tools and we include easy-to-follow instructions.
Will this fix my check engine light?
If the check engine light and associated codes are caused by a faulty PCM, this part is the correct solution. It’s crucial to ensure other potential issues (like bad sensors or wiring) have been ruled out for a complete and lasting repair.
Is this a new or used part?
This is a high-quality, guaranteed replacement part that has been meticulously inspected and prepared to meet or exceed original equipment performance. It is loaded with fresh, vehicle-specific software to ensure optimal operation.
What information do you need from me?
After you complete your purchase, we will need the 17-digit Vehicle Identification Number (VIN) from your vehicle. You can typically find this on your driver’s side dashboard (visible through the windshield) or on the door jamb sticker.