Restore Your GM Diesel’s Brainpower and Performance
If your 2013-2014 GM workhorse with the 6.6L Duramax engine is suffering from no-start conditions, erratic shifting, a persistent check engine light, or poor fuel economy, the Engine Control Module (ECM) is a likely culprit. As a technician with over two decades of diagnostic experience, I’ve seen firsthand how a failing ECM can bring even the toughest trucks to a dead stop. This isn’t just a part; it’s the central computer responsible for managing everything from fuel injection timing to transmission commands. A faulty one can cause a cascade of frustrating and hard-to-diagnose problems.
This listing is for a genuine, used OEM Engine Control Module, service number 12653319 (also interchangeable with 12654088). We take the biggest headache out of the repair process for you. Before we ship this module, our experts will program it with the latest official GM calibrations specifically for your vehicle. All we need is your Vehicle Identification Number (VIN) at checkout. This saves you a costly trip to the dealership and eliminates the need for expensive programming hardware on your end. Get a reliable, cost-effective solution with the core programming already handled.
Is Your Duramax Showing These Symptoms?
A failing ECM can manifest in many ways. If you’re experiencing any of the following, this module is the likely solution. In my shop, these are the classic signs I look for:
- ✔ Complete no-start or intermittent starting issues.
- ✔ Check Engine Light is on with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ Poor engine performance, hesitation, or stalling.
- ✔ Noticeable decrease in fuel mileage.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Communication errors with other modules (U-codes).
- ✔ Engine running in a reduced power or “limp” mode.
Case Study: The Intermittent No-Start
A customer brought in a 2013 Silverado 2500 that would randomly refuse to start. No crank, no click. He had already replaced the battery and starter to no avail. The issue was intermittent, making it a diagnostic nightmare. After checking all the power and ground circuits, we hooked up our scan tool and found intermittent communication loss with the ECM. We temporarily swapped in a known-good module, and the problem vanished. The original ECM had an internal failure that only appeared when it heated up. This programmed 2013-2014 Express 2500 ECM fixed his truck for good, saving him from chasing phantom electrical gremlins.
A Straightforward Guide to Installation
Replacing the ECM is a manageable job for a DIYer or professional. With our pre-programming service, the most complex step is already done. Here’s a general overview of the process:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the ECM: On Express/Savana vans, it’s typically in the LH rear of the engine compartment. On Silverado/Sierra trucks, it’s on the LH front side of the engine compartment.
- Disconnect Connectors: Carefully unlatch and remove the electrical connectors from the old ECM. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt your new, pre-programmed ECM into place and securely reconnect the electrical connectors.
- Reconnect Battery: Re-attach the negative battery terminal.
- Perform Relearn Procedures: This is a critical final step. The vehicle will not start until a Vehicle Theft Deterrent (VTD) relearn is performed using a capable scan tool or the GM TIS2WEB system. Other procedures like a crankshaft position variation relearn or injector flow rate programming may also be necessary depending on your specific vehicle and situation. This is the responsibility of the installer.
Verified Fitment for Your GM HD Truck or Van
This module is a direct replacement for service number 12653319 or 12654088 in a wide range of GM vehicles equipped with the 6.6L Duramax diesel engine. Please verify your part number before ordering. This part fits:
- Chevrolet Express 2500/3500 Van: 2013, 2014
- GMC Savana 2500/3500 Van: 2013, 2014
- Chevrolet Silverado 2500/3500 Pickup: 2013, 2014
- GMC Sierra 2500/3500 Pickup (including Denali): 2013, 2014
Note for 2014 Vans: Fits models without the “pull-ahead design” option.
Frequently Asked Questions
Is this part new?
No, this is a high-quality, fully functional used ECM recovered from a salvaged vehicle. It has been tested and is ready for programming and installation.
What do you mean by “programmed to my VIN”?
Before we ship the part, we use your Vehicle Identification Number (VIN) to load the correct, factory-approved GM software and calibrations onto the module. This ensures it communicates properly with your specific truck’s engine, transmission, and options.
Will my truck start immediately after I install this?
No. After installation, you or your mechanic MUST perform a Vehicle Theft Deterrent (VTD) relearn procedure. This security handshake is required to allow the engine to start. This is standard for all GM ECM replacements.
What tools are needed for the VTD relearn?
The theft relearn requires a professional-grade scan tool with GM-specific capabilities or access to the official GM TIS2WEB online service. Many independent repair shops have this capability.
Where do I find my VIN?
Your 17-digit VIN can be found on your vehicle’s registration, insurance card, or on a small plate on the driver’s side of the dashboard, visible through the windshield.
Why should I buy this instead of one from a junkyard?
A standard junkyard ECM will not be programmed for your vehicle. You would still need to pay a dealership or specialized shop for programming, which can be expensive. We provide a tested part with the programming already completed, offering a more direct and economical repair path.