Restore Your Duramax’s Performance and Reliability
Is your 2013-2014 GM HD truck or van suddenly giving you headaches? A no-start condition, erratic engine behavior, or a dashboard full of warning lights can often point to one critical component: the Engine Control Module (ECM). As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing ECM can bring even the toughest Duramax to a standstill. This isn’t just a part; it’s the brain of your engine, and when it falters, everything else does too.
This listing is for a dependable, used OEM Engine Control Module, part number 12654088 (also compatible with service number 12653319). We take the biggest hassle out of the replacement process for you. Simply provide your vehicle’s VIN at checkout, and our team will professionally program this module with the latest factory software calibrations from GM. This ensures it communicates perfectly with your specific vehicle, saving you a costly trip to the dealership for initial programming.
Case Study: A Tricky Diagnosis
A customer brought in a 2014 Sierra 2500 with an intermittent no-start that was driving him crazy. It would be fine for a week, then refuse to crank for an hour. No consistent codes were stored, just a few random communication faults (U-codes) that would clear. We checked the battery, starter, and grounds—all perfect. On a hunch, I tapped the ECM while an assistant tried to start it, and it fired right up. A hairline crack on the internal circuit board, invisible to the naked eye, was causing the intermittent connection. Replacing the ECM with a correctly programmed unit like this one solved the problem for good. These symptoms can be elusive, but they often lead back to the engine’s central computer.
Is Your Truck Showing These Signs of a Bad ECM?
A faulty ECM can manifest in various ways. If you’re experiencing any of the following, this module is likely the solution you need:
- âś” Complete no-start or no-crank condition.
- âś” Engine stalls unexpectedly while driving or at idle.
- âś” Check Engine Light is on with communication error codes like U0100, P0601, or P0606.
- âś” Poor fuel economy or a noticeable loss of power.
- âś” Harsh or incorrect transmission shifting.
- âś” Problems with the anti-theft system or other electronic features.
A Straightforward Guide to Installation
Replacing the 2013-2014 Silverado 3500 ECM is a manageable job for a DIYer with basic tools or a professional mechanic. Since we handle the initial programming, you’re already halfway there. Follow these general steps for a successful installation:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait a few minutes for the system to discharge completely.
- Locate the ECM: On most 2013-2014 Sierra and Silverado trucks, the ECM is located in the front left (driver’s side) of the engine compartment. On Express and Savana vans, it’s typically on the left-hand rear side of the engine compartment.
- Disconnect and Remove: Carefully unplug the large electrical connectors. There are usually locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed ECM into place and securely reconnect the electrical harnesses. Ensure they click into place to confirm a solid connection.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Relearn Procedures: This step is critical. If the truck doesn’t start, you must perform a Vehicle Anti-Theft System (VATS) relearn using a compatible scan tool or the GM TIS2Web service. Other procedures like a crankshaft position variation relearn or injector flow rate programming may also be required for optimal performance. Please note: Completing these relearn procedures is the responsibility of the installer.
Verified Fitment for Your GM HD Vehicle
This ECM is a direct-fit replacement for a range of GM trucks and vans equipped with the 6.6L Duramax diesel engine. Please verify your part number and vehicle application from the list below.
- Chevrolet Silverado 2500/3500 Pickup: 2013, 2014
- GMC Sierra 2500/3500 Pickup: 2013, 2014
- GMC Sierra Denali 2500/3500: 2013, 2014
- Chevrolet Express 2500/3500 Van: 2013, 2014
- GMC Savana 2500/3500 Van: 2013, 2014
Frequently Asked Questions
Frequently Asked Questions
Do I need to do anything after I install this ECM?
Yes. While we program the module to your VIN, you or your mechanic MUST perform a security relearn procedure (also known as VATS or Passlock relearn) for the vehicle to start. Additional relearns, like for the crankshaft position sensor, may also be necessary.
What information do you need from me?
After you place your order, you must provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). We cannot ship your part until we receive this information to program it correctly.
Is this a brand new part?
No, this is a high-quality, tested, and fully functional used OEM part sourced from a salvaged vehicle. This provides a reliable and cost-effective alternative to a new dealership part.
Will this fix my truck’s problem?
This part will resolve issues directly caused by a faulty ECM, such as those listed in the symptoms section. Proper vehicle diagnosis is key. If you have any doubts, we recommend consulting a professional mechanic to confirm the ECM is the point of failure before ordering.
What tools are needed for the security relearn?
The security relearn procedure typically requires a professional-grade scan tool with GM-specific software or access to the official GM TIS2Web programming system. This is not something that can be done with a basic code reader.
Why choose a VIN-programmed module?
A VIN-programmed module ensures that your vehicle’s specific options, emissions calibrations, and security information are correctly loaded. This is essential for proper engine function, transmission operation, and preventing compatibility issues.