Restore Peak Performance to Your 2016 Savana 3500 Van
If your workhorse 2016 Savana 3500 is suddenly stalling, running rough, or refusing to start, the problem often lies with a failing Engine Control Module (ECM). As the brain of your vehicle’s powertrain, a faulty ECM can cause a cascade of frustrating and costly issues, keeping your van off the road and impacting your business. This isn’t just an inconvenience; it’s lost time and money. This replacement ECM, part number 12668991, is the definitive solution, arriving at your door pre-programmed to your specific vehicle.
We take the guesswork and extra expense out of the equation. Simply provide us with your Vehicle Identification Number (VIN) during checkout, and our technicians will flash this module with the latest, most stable General Motors software for your exact configuration. This means you can bypass the dealership’s high programming fees and lengthy service appointments. Get the reliability you depend on with a part that’s ready to install right out of the box.
A Technician’s Notebook: The Intermittent No-Start Nightmare
I had a fleet manager bring in a 2016 Express 3500—the Savana’s twin—with a maddening issue. It would start and run perfectly for a week, then refuse to start for two days straight, showing no specific codes other than a random U0100 (Lost Communication with ECM). The crew had already replaced the battery and checked all the main power and ground wires. After hours of diagnostics, we found that the ECM’s internal processor was failing under certain temperature conditions. We swapped in one of our pre-programmed modules, performed the security relearn, and the van was back in reliable service the same afternoon. That’s the power of having a dependable, ready-to-go part.
Is Your Savana Van Showing These Signs of ECM Failure?
A failing ECM can manifest in various ways. If you’re experiencing any of the following, it’s a strong indicator that your engine’s computer needs attention:
- ✔ Persistent Check Engine Light (CEL) that won’t clear
- ✔ Engine cranks but refuses to start
- ✔ Unexplained drops in fuel economy
- ✔ Rough or unstable idling
- ✔ Vehicle stalling unexpectedly
- ✔ Noticeable loss of power and poor acceleration
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Diagnostic trouble codes (DTCs) pointing to internal module failure (e.g., P0601, P0606) or communication errors (U0100).
A Straightforward Guide to Installation
Replacing the ECM on your Savana is a manageable job for a confident DIYer or any professional technician. This module is designed for a direct fit, but you must perform a security relearn procedure after installation for the vehicle to start.
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the ECM: On the 2016 Savana 3500, the Engine Control Module is typically found in the left-hand (driver’s side) rear of the engine compartment.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. They have locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket and remove it.
- Install the New Module: Bolt the new, pre-programmed ECM into place. Reconnect the wiring harnesses, ensuring they click securely into position.
- Reconnect Battery: Reattach the negative battery terminal and tighten it.
- Perform Security Relearn (CRITICAL STEP): Your vehicle will not start until you complete the GM security relearn procedure (also known as the Passlock or anti-theft relearn). This simple process typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating two more times. This allows the new ECM to sync with your vehicle’s anti-theft system.
Guaranteed Fitment for Your GM Vehicle
This ECM is a direct replacement for part number 12668991 and is also compatible with several other service numbers. While programmed specifically for your 2016 Savana 3500, this hardware is used across a wide range of GM trucks, vans, and cars, including:
- ✔ Chevrolet Express & GMC Savana 2500/3500 Vans (2016): With 4.8L or 6.0L engines.
- ✔ Chevrolet Silverado & GMC Sierra 2500/3500 Pickups (2012-2016): With 6.0L engines.
- ✔ Chevrolet Suburban 3500 (2016)
- ✔ Chevrolet Cruze (2012-2016)
- ✔ Chevrolet Sonic (2012-2016)
- ✔ Chevrolet Trax (2013-2016)
- ✔ Chevrolet Volt (2011-2015) & Cadillac ELR (2014-2016)
- ✔ Buick Encore (2013-2016)
- ✔ Chevrolet Spark (2014-2015)
Note: Always verify compatibility by matching your original part number or providing your VIN. This module replaces part numbers: 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, and 12692200.
Frequently Asked Questions
What does ‘pre-programmed’ mean for my van?
It means we load the module with the official GM software specific to your van’s VIN before we ship it. This ensures correct engine, transmission, and emissions control, and lets you avoid a separate, costly programming service at a dealership.
Do I need to do anything after installing this ECM?
Yes. After installation, you must perform a security relearn procedure. This is a simple process that syncs the new ECM to your vehicle’s anti-theft system and is required for the engine to start. Instructions are widely available online or in service manuals.
Where is the ECM located on my 2016 Savana 3500?
The ECM is located in the engine compartment, on the driver’s side towards the rear firewall.
Will this fix my specific problem or Check Engine Light code?
This module will correct issues directly caused by a faulty ECM, including internal failure codes like P0601. However, proper diagnosis is key. If your check engine light is on for a bad sensor, this part will not fix that. Always confirm the ECM is the source of the problem before ordering.
How do I provide my VIN for programming?
After you complete your purchase, you will need to send us a message with your 17-digit VIN. We cannot program and ship your module without it.