Restore Peak Performance to Your GM Vehicle
Is your work van or truck suddenly unreliable? A faulty Engine Control Module (ECM), also known as the Powertrain Control Module (PCM), is often the hidden culprit behind frustrating issues like a persistent check engine light, poor fuel economy, or a vehicle that refuses to start. As the brain of your vehicle’s engine, when the ECM fails, it can cause a cascade of problems that can sideline your vehicle and disrupt your work. This isn’t just an inconvenience; it’s lost time and money. This replacement ECM is the direct, reliable solution to get your vehicle operating correctly again.
We take the guesswork and hassle out of the replacement process. Unlike a generic module from a parts store, this unit arrives at your door pre-programmed with the latest official GM software updates. All we need is your vehicle’s 17-digit VIN during checkout. This critical step ensures the module communicates flawlessly with your specific vehicle’s systems—from the transmission to the anti-lock brakes—restoring factory performance and efficiency without a costly trip to the dealership for programming.
Case Study: The Ghost in the Machine
I had a 2016 Express 2500 work van come into my bay that was driving the owner crazy. It had an intermittent no-start condition with no rhyme or reason. Sometimes it would fire right up, other times the starter would crank but the engine wouldn’t catch. There were no consistent trouble codes, just a generic U0100 ‘Lost Communication with ECM/PCM’ that would pop up occasionally. After verifying the wiring harness, grounds, and power feeds were solid, I suspected the ECM itself was failing internally. The internal processor was likely malfunctioning due to heat cycles and vibration. Swapping in one of our VIN-programmed modules solved the problem instantly. The van has been starting reliably for the client ever since, proving that a solid, correctly programmed ECM is the foundation of a dependable vehicle.
Is Your GM Vehicle Showing These ECM Failure Signs?
- ✔ Check Engine Light is on with codes pointing to internal module failure (like P0601, P0606) or communication errors (U-codes).
- ✔ The engine cranks but refuses to start, or starts and immediately stalls.
- ✔ Noticeable decrease in fuel efficiency for no apparent reason.
- ✔ The transmission shifts erratically, harshly, or gets stuck in one gear (limp mode).
- ✔ Misfires, rough idling, or stalling that can’t be traced to spark plugs or coils.
- ✔ Other warning lights on the dash (ABS, Traction Control) may illuminate due to communication loss with the ECM.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental reconnection.
- ✔ Locate the ECM: On the Savana/Express vans, the ECM is typically located in the rear of the engine compartment on the driver’s side. On other models like the Silverado/Sierra, it’s on the driver’s side front of the engine compartment.
- ✔ Disconnect Connectors: Carefully release the locking tabs and unplug the wiring harness connectors from the old ECM. Inspect the connectors for any corrosion or damaged pins.
- ✔ Remove the Old Module: Unbolt the old ECM from its mounting bracket. There are usually a few bolts holding it in place.
- ✔ Install the New Module: Mount your new, pre-programmed ECM onto the bracket and securely fasten the bolts.
- ✔ Reconnect Everything: Plug the wiring harness connectors firmly into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Final Steps: Your vehicle is now ready to start. In some cases, a security relearn procedure may be required, which can typically be done without special tools by cycling the key.
Guaranteed Fitment for a Wide Range of GM Models
This module is a direct replacement for part numbers 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, and 12692200, ensuring compatibility with a variety of vehicles. Please verify your part number or contact us with your VIN to confirm.
- ✔ Buick Encore: 2013-2016 (1.4L)
- ✔ Cadillac ELR: 2014-2016
- ✔ Chevrolet Cruze: 2012-2016 (Gasoline models)
- ✔ Chevrolet Express 2500/3500 Van: 2016 (4.8L, 6.0L)
- ✔ Chevrolet Silverado 2500/3500 Pickup: 2012-2016 (6.0L)
- ✔ Chevrolet Sonic: 2012-2016
- ✔ Chevrolet Spark: 2014-2015 (Gasoline)
- ✔ Chevrolet Suburban 3500: 2016
- ✔ Chevrolet Trax: 2013-2016
- ✔ Chevrolet Volt: 2011-2015
- ✔ GMC Savana 2500/3500 Van: 2016 (4.8L, 6.0L)
- ✔ GMC Sierra 2500/3500 Pickup (including Denali): 2012-2016 (6.0L)
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming before shipment. This module arrives ready for installation, flashed with the latest GM software for your specific VIN.
Where do I provide my VIN?
You can add your 17-digit Vehicle Identification Number (VIN) in the notes section during checkout. If you forget, we will contact you to get it before we can program and ship your part.
Is this a simple part to replace for a DIYer?
Yes, for most individuals with basic mechanical skills. The module is typically easy to access and requires only simple hand tools to unbolt and swap. The most important part is that our pre-programming saves you the most complex step.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the ECM (common codes include P0601-P0606), then this part is the correct fix. It’s crucial to properly diagnose the issue first, as other sensors or wiring problems can also trigger a check engine light.
What if my original part number is not 12643636?
This module also replaces several other part numbers, including 12668866, 12668994, and more as listed in the description. As long as your vehicle and engine match our fitment list, this module will work once programmed to your VIN.