Restore Your Sierra’s Core Performance and Reliability
As a technician with over two decades of experience under the hood, I know the frustration that comes with a failing Engine Control Module (ECM). It’s the brain of your 2012-2016 Sierra 2500, and when it starts to falter, it can cause a cascade of confusing and costly problems. From a truck that won’t start to erratic engine behavior that leaves you stranded, a bad ECM can cripple your workhorse. This isn’t just a replacement part; it’s a complete, reliable solution. We take the guesswork and dealership hassle out of the equation by pre-programming this module to your truck’s specific Vehicle Identification Number (VIN) with the latest GM-certified software. This ensures perfect communication between all your vehicle’s systems, restoring the performance and dependability you count on every day.
A Technician’s Notebook: The Intermittent No-Start
I once had a 2014 Sierra 2500 in my bay that was giving the owner fits. It would randomly refuse to start, but only after it was warm. All the usual suspects—battery, starter, fuel pump—checked out fine. We scanned it and found a generic U0100 ‘Lost Communication with ECM/PCM’ code, but it was intermittent. After hours of tracing wires, we swapped in a known-good ECM. The problem vanished instantly. The original module had an internal hairline fracture on the circuit board that would separate when it heated up, breaking the connection. It’s a classic example of how a failing ECM can mimic other issues, making a reliable, pre-programmed replacement the most efficient fix.
Is Your Sierra Showing These Red Flags?
A faulty ECM often announces itself with clear symptoms. If you’re experiencing any of the following, it’s a strong indicator that your engine’s computer needs attention:
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ Vehicle refuses to start or has intermittent starting problems.
- ✔ Noticeable decrease in fuel economy.
- ✔ Engine stalling, sputtering, or running rough for no apparent reason.
- ✔ Automatic transmission shifting harshly or at the wrong times.
- ✔ Loss of power and poor acceleration.
- ✔ Communication errors with diagnostic scan tools.
Straightforward Installation Guide for Your Sierra
Getting your truck back in top form is easier than you think. This module is located in the front left of the engine compartment. Follow these steps for a successful installation:
- Safety First: Always disconnect the negative terminal from your truck’s battery and wait at least 15 minutes to allow all system capacitors to discharge.
- Locate the ECM: On your Sierra 2500, you’ll find the ECM mounted on the driver’s side of the engine bay, near the firewall or inner fender.
- Disconnect the Connectors: Carefully release the locking tabs on the electrical wiring harnesses and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket. There are typically a few 10mm bolts holding it in place.
- Install the New Module: Mount your new, pre-programmed ECM onto the bracket and secure it with the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new module until you hear them click into place. Reconnect the negative battery terminal.
- Final Check: Turn the key to the ‘On’ position for 10-15 seconds before starting the engine. This allows the vehicle’s systems to recognize the new ECM. Start your truck and enjoy the restored performance!
Verified Compatibility Across GM Models
While this is a direct-fit solution for the 2012-2016 Sierra 2500 with the 6.0L engine, this versatile module is also compatible with a wide range of other GM vehicles. Please verify your part number (this module replaces 12668866, 12668994, 12643636, and others) and vehicle from the list below.
Primary Truck/Van Fitment:
- SIERRA 2500/3500 PICKUP (2012-2016): Electronic Control Module; (LH front engine compartment), 6.0L
- SILVERADO 2500/3500 PICKUP (2012-2016): Electronic Control Module; (LH front engine compartment), 6.0L
- EXPRESS/SAVANA 2500 & 3500 VAN (2016): Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L
- SUBURBAN 3500 (2016): Electronic Control Module; (LH front engine compartment)
Additional Vehicle Fitment:
- BUICK ENCORE (2013-2016): 1.4L
- CADILLAC ELR (2014-2016): Gasoline
- CHEVROLET CRUZE (2012-2016): 1.4L or Gasoline
- CHEVROLET SONIC (2012-2016): 1.4L
- CHEVROLET SPARK (2014-2015): Gasoline Model
- CHEVROLET TRAX (2013-2016)
- CHEVROLET VOLT (2011-2015): Gasoline
Frequently Asked Questions
How does the programming process work?
It’s simple. After you complete your purchase, you will need to send us your vehicle’s 17-digit VIN. Our technicians will then use this VIN to load the latest, most stable GM software specifically for your truck’s configuration onto the module before we ship it to you.
Is this a true plug-and-play installation?
Yes. Because we program the module to your VIN, it is ready for installation right out of the box. In most cases, you will not need to perform any additional security relearn procedures or pay for dealer programming.
Where do I find my VIN?
Your VIN can be found on your vehicle’s registration, insurance card, or on the driver’s side of the dashboard, visible through the windshield.
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), then this part will resolve the issue. It’s always best to have a proper diagnosis to confirm the ECM is the root cause before ordering.
Does this part come with a warranty?
Yes, all our modules come with a warranty that protects against defects in the part itself. Please see our warranty policy page for complete details and duration.
What part number should I match?
This module, 22819494, is a direct replacement for several part numbers, including 12668866, 12668994, 12643636, 12663405, 12670335, and 12692200. As long as your vehicle is on the fitment list, this module is the correct replacement.