Restore Your Truck’s Core Performance with a VIN-Programmed ECM
If you’re dealing with frustrating engine problems in your GM truck, van, or performance car, the root cause is often the very brain of the operation: the Engine Control Module (ECM). A failing ECM can turn a reliable workhorse into a source of constant headaches, from poor fuel mileage and rough idling to a complete no-start situation. This isn’t just an inconvenience; it affects your work, your safety, and your peace of mind. We offer a dependable, straightforward solution: a replacement ECM, part number 12633055, programmed specifically for your vehicle’s VIN.
Forget the expensive trip to the dealership and the hassle of coordinating programming. We handle the critical software flashing for you. Simply provide your vehicle’s VIN after purchase, and our technicians will load the latest, most stable GM-approved software onto the module before it ships. This ensures that all factory parameters for your specific engine, transmission, and emissions equipment are perfectly matched, restoring the performance and efficiency you expect from your vehicle. This is the most direct path to fixing complex electronic issues and getting back on the road with confidence.
A Technician’s Notebook: The Intermittent Stall
I remember a 2010 Sierra 2500 6.0L that came into my bay with a ghost of a problem. The owner said it would randomly stall at red lights, then start right back up. No check engine light, no stored codes—the usual suspects checked out fine. After days of testing sensors and wiring, I monitored the live data stream from the ECM during a long test drive. I finally caught it: for a split second, the 5-volt reference signal to the throttle body would drop out, causing the stall. It was an internal failure in the ECM’s power regulation circuit, something you’d never find with a simple code scan. Swapping in a pre-programmed ECM like this one resolved the issue instantly. It’s a reminder that for these complex systems, a solid ‘brain’ is everything.
Is Your Vehicle Showing These Symptoms?
A failing ECM can manifest in numerous ways. As the central computer for your engine, even a small internal glitch can cause major performance issues. Here are some of the most common signs I’ve seen in my 20+ years of diagnostics:
- ✔ Check Engine Light is on with communication or internal processor codes (e.g., P0601, P0606, U0100).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Rough or erratic engine idling.
- ✔ Vehicle stalls unexpectedly while driving or at a stop.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Noticeable loss of power and poor acceleration.
- ✔ Communication issues with diagnostic scan tools.
Your Straightforward Guide to Installation
Installing your new 2010 Sierra 2500 ECM is a manageable task for a DIYer with basic tools. The key is taking your time and following the proper procedure, especially the security relearn at the end.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow the system to fully discharge.
- Locate the ECM: On most Sierra/Silverado trucks and SUVs, the ECM is located in the engine bay, on the driver’s side near the fender or firewall. It’s a silver metal box with several large wiring harness connectors.
- Disconnect and Remove: Carefully release the locking tabs on each wiring harness connector and pull them straight out. Avoid wiggling them side-to-side to prevent pin damage. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed ECM into the mounting bracket. Firmly reconnect the wiring harnesses, ensuring they click securely into place.
- Reconnect the Battery: Re-attach the negative battery terminal and tighten it securely.
- Perform Security Relearn (CRITICAL): This step pairs the new ECM with your vehicle’s anti-theft system. Turn the key to the ‘ON’ position (do not start) for 10-15 minutes, or until the security light on the dash stops flashing and turns off. Turn the key off for 10 seconds. Repeat this cycle two more times (for a total of three cycles). The vehicle should now start and run normally.
Verified Vehicle Compatibility
This ECM is a direct replacement for part numbers 12633055 and 12633238. It fits a wide range of GM vehicles. Please confirm your model and engine options from the list below to ensure a perfect match.
CAMARO 10-15 (6.2L, 7.0L)
CAPRICE 11-17 (6.0L)
CORVETTE 10-13 (6.2L, 7.0L)
ESCALADE / ESV / EXT 10-14
EXPRESS VAN 1500/2500/3500 10-15 (4.8L, 5.3L, 6.0L)
SAVANA VAN 1500/2500/3500 10-15 (4.8L, 5.3L, 6.0L)
SIERRA 1500/DENALI 1500 10-13 (4.8L, 5.3L, 6.2L)
SIERRA 2500 PICKUP 10 (6.0L, VIN G)
SIERRA 3500 PICKUP 10 (6.0L, VIN G)
SILVERADO 1500 PICKUP 10-13 (4.8L, 5.3L, 6.2L)
SILVERADO 2500 PICKUP 10 (6.0L, VIN G)
SILVERADO 3500 PICKUP 10 (6.0L, VIN G)
SS CAPRICE 14-17
SUBURBAN 1500/2500 10-14
TAHOE 10-14 (w/o hybrid)
YUKON / XL 1500 / XL 2500 10-14 (w/o hybrid)
Frequently Asked Questions
Do I really need to provide my VIN?
Do I really need to provide my VIN?
Yes, providing your 17-digit VIN is essential. We use it to load the exact GM factory software for your vehicle’s specific engine, transmission, and options. This step is what makes the installation a simple plug-and-play process without needing a trip to the dealer.
Is this a plug-and-play part?
Because we program it to your VIN before shipping, it is nearly plug-and-play. The only additional step required after physical installation is the security relearn procedure, which can be done at home without any special tools. We provide instructions for this simple process.
Will this fix my Check Engine Light?
If your Check Engine Light is caused by an internal ECM failure (like codes P0601-P0606), then yes, this module will resolve the problem. However, if the light is on due to a faulty sensor or wiring issue elsewhere on the vehicle, you will still need to diagnose and repair that separate issue.
What if my part number is 12633238?
This module is a direct replacement for both 12633055 and 12633238. They are interchangeable GM part numbers, and this unit will function correctly for all applications listed.