Restore Peak Performance to Your GM Vehicle
Is your work van or truck suddenly running rough, stalling, or refusing to start? A persistent Check Engine Light can be more than just an annoyance; it’s often a sign that the ‘brain’ of your engine—the Engine Control Module (ECM)—is failing. As a technician with over two decades of experience, I’ve seen firsthand how a faulty ECM can cause a cascade of frustrating issues, from poor fuel economy to unpredictable transmission behavior. This isn’t just a part; it’s the central command for your vehicle’s most critical functions. This replacement Engine Control Module, part number 12668991, is the reliable solution to get your vehicle operating smoothly and efficiently again.
The biggest hurdle with ECM replacement has always been the programming. In the past, you’d buy the part, install it, and then have to get your vehicle towed to a dealership for an expensive programming session. We eliminate that step entirely. Before this module ships, we will flash it with the latest official GM software, precisely matched to your vehicle’s unique Vehicle Identification Number (VIN). This ensures perfect communication between the module and all your vehicle’s systems, just as the factory intended. This is the most direct path to fixing your vehicle right, the first time.
A Technician’s Notebook: The Ghost in the Machine
I remember a 2016 Express 3500 work van that came into my shop. The owner was at his wit’s end. The van would randomly stall at traffic lights, the transmission would shift harshly, and he had a check engine light with a U0100 code (Lost Communication with ECM). He’d already replaced a few sensors with no luck. After confirming power and ground to the module were good, we diagnosed a failing ECM. The internal communication processors were failing intermittently, especially when hot. Installing a pre-programmed ECM like this one solved every single one of his issues in under an hour. It’s a classic failure mode for these hard-working vehicles, and this is the definitive fix.
Is Your Vehicle Showing These Signs of ECM Failure?
A failing ECM can manifest in many ways. If you’re experiencing any of the following, this module is likely the solution you need. Look out for:
- ✔ Check Engine Light is on with codes like P0601, P0606, or U0100
- ✔ Engine cranks but will not start
- ✔ Stalling, stuttering, or hesitation during acceleration
- ✔ Noticeable drop in fuel mileage
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Communication issues with diagnostic scan tools
- ✔ Misfires or rough idle even after replacing plugs and coils
A Straightforward Guide to Installation
Installing your new 2016 Express 3500 Van ECM is a manageable job for a confident DIYer or any professional mechanic. With our pre-programming service, no special scan tools are required for the installation itself.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes to allow capacitors to discharge.
- Locate the Old ECM: On the 2016 Express/Savana vans, the ECM is typically located in the rear of the engine compartment on the driver’s side. On trucks like the Silverado/Sierra, it’s often on the driver’s side front of the engine compartment.
- Disconnect 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 Module: Unbolt the old ECM from its mounting bracket. Keep the hardware as you will reuse it.
- Install the New ECM: Mount your new, pre-programmed module in place and secure it with the original hardware.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new ECM until they click into place. Reconnect the negative battery terminal.
- Final Step: Some vehicles may require a security relearn procedure, which typically involves turning the key to the ‘ON’ position for 10-15 minutes. Your vehicle’s service manual can provide specific instructions if needed.
Verified Vehicle Compatibility List
This module is a direct replacement for part number 12668991 and also interchanges with part numbers 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, and 12692200. It is guaranteed to fit the following GM models with the specified options:
- ✔ Chevrolet Express 2500/3500 Van (2016) – 4.8L & 6.0L Engines
- ✔ GMC Savana 2500/3500 Van (2016) – 4.8L & 6.0L Engines
- ✔ Chevrolet Silverado 2500/3500 Pickup (2012-2016) – 6.0L Engine
- ✔ GMC Sierra 2500/3500 Pickup (2012-2016) – 6.0L Engine
- ✔ Chevrolet Cruze (2012-2016) – Check specific engine/ID
- ✔ Chevrolet Sonic (2012-2016) – Check specific engine/ID
- ✔ Chevrolet Trax (2013-2016)
- ✔ Chevrolet Volt (2011-2015)
- ✔ Chevrolet Spark (2014-2015) – Gasoline models
- ✔ Buick Encore (2013-2016) – 1.4L Engine
- ✔ Cadillac ELR (2014-2016)
- ✔ Chevrolet Suburban 3500 (2016)
Ordering this 2016 Express 3500 Van ECM is your first step toward a reliable repair. Simply provide your VIN at checkout, and we’ll handle the rest, sending you a part that’s ready to install right out of the box.
Frequently Asked Questions
Do I need to do any extra programming after installation?
No. We program the module to your vehicle’s VIN before shipping. In most cases, it is a plug-and-play installation. Some vehicles may require a simple key-cycle security relearn, but no special tools are needed.
What is a VIN and why do you need it?
The VIN (Vehicle Identification Number) is a unique 17-digit code for your specific vehicle. We use it to load the correct factory software and calibrations for your engine, transmission, and options, ensuring perfect compatibility.
Where is the ECM located on my 2016 Express 3500 Van?
On the 2016 Express and Savana vans, the ECM is typically found in the engine compartment, mounted on the driver’s side, toward the rear firewall area.
Is this a reliable, long-term fix?
Absolutely. This is a high-quality replacement module, and by programming it with the latest GM software updates, we often resolve issues that the original factory software may have had. It’s designed to restore original performance and reliability.
What happens after I place my order?
After you purchase, you will need to send us your vehicle’s VIN. Once we receive it, our technicians will program the module, which typically takes one business day. We will then ship the ready-to-install part directly to you.