Is your reliable 2013-2014 GM work van or truck suddenly giving you headaches? Unexplained stalling, a persistent check engine light, or a no-start condition can bring your work to a grinding halt. As a technician with over two decades of experience, I’ve seen how a faulty Engine Control Module (ECM) can cause some of the most frustrating and difficult-to-diagnose issues on the 6.6L Duramax engine. This isn’t just an inconvenience; it’s lost time and money.
This is a genuine, used GM Engine Control Module, part number 12654088 (also compatible with service number 12653319), that offers a dependable and cost-effective solution. The biggest hurdle with ECM replacement is programming, which typically requires an expensive trip to the dealership. We solve that problem for you. Before this module ships, we flash it with the latest official GM software calibrations, precisely matched to your vehicle using the VIN you provide. This ensures the ECM communicates perfectly with your van’s specific systems right out of the box.
From the Diagnostic Bay: The Phantom Electrical Gremlin
I remember a 2013 Silverado 3500 that came into my shop with an intermittent no-start condition that was driving the owner crazy. It would work fine for a week, then refuse to crank for an hour. There were no consistent trouble codes, just a random U0100 ‘Lost Communication with ECM’ code that would appear and disappear. We spent hours checking the CAN bus wiring, testing grounds, and inspecting connectors. Everything looked perfect. On a hunch, we swapped in a known-good ECM, and the problem vanished. The original module had an internal failure that only occurred at a specific operating temperature, making it a true phantom fault. This is a classic failure mode for these units.
Is Your 6.6L Duramax Showing These Signs?
A failing ECM can manifest in many ways. If you’re experiencing any of the following, a faulty module could be the culprit:
- ✔ Vehicle will not start or cranks but won’t fire.
- ✔ Sudden stalling or rough idling for no apparent reason.
- ✔ Check Engine Light is illuminated with internal module codes like P0601, P0606, or P062B.
- ✔ Loss of communication codes (U-codes) pointing to the ECM.
- ✔ Noticeable decrease in fuel economy or engine performance.
- ✔ Issues with automatic transmission shifting, as the ECM and TCM work together.
A Straightforward Guide to Installation
Installing your pre-programmed 2013-2014 Savana 3500 ECM is a manageable job for a confident DIYer or any professional mechanic. Follow these general steps to get your vehicle running again.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent any accidental reconnection.
- Locate the ECM: On Savana and Express vans, the ECM is typically found in the LH rear of the engine compartment. On Sierra and Silverado pickups, it’s located in the LH 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 damage.
- Remove Old Module: Unbolt the mounting hardware holding the old ECM in place and remove it from the vehicle.
- Install New Module: Mount your replacement ECM and securely tighten the hardware. Reconnect the wiring harnesses, ensuring they click firmly into place.
- Reconnect Battery: Re-attach the negative battery terminal.
- Perform Relearn Procedures: This is a critical final step. Turn the key to the ‘ON’ position. If the vehicle does not start, you will need to perform a Vehicle Theft Deterrent (VTD) relearn. See our FAQ below for more details.
Important Notice: While we handle the main programming, the final installation is your responsibility. This includes performing the VTD relearn and any other necessary procedures like a crankshaft variation relearn or injector flow rate programming, which may require a professional scan tool with GM TIS2Web access.
Verified Fitment for Your GM Truck or Van
This module is guaranteed to fit the following vehicles equipped with the 6.6L Duramax diesel engine. Please match your part number or contact us with your VIN to confirm compatibility.
- 2013-2014 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
- 2013-2014 GMC Sierra Denali 2500/3500
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to flash the ECM with the exact software and calibrations specified by GM for your truck or van’s unique configuration. This step is essential for proper engine, transmission, and emissions system operation.
What is a Vehicle Theft Deterrent (VTD) relearn?
The VTD system links your ECM to your vehicle’s ignition key and Body Control Module. If the vehicle doesn’t start after installation, this security handshake needs to be reset. This procedure typically requires a compatible scan tool and access to the GM TIS2Web programming system. It is the responsibility of the installer.
Is this a new part?
No, this is a high-quality, tested used ECM sourced from a salvaged vehicle. It has been inspected and confirmed to be fully functional before being programmed for your vehicle.
Will this 2013-2014 Savana 3500 ECM definitely fix my problem?
This part will resolve issues directly caused by a faulty ECM. However, proper vehicle diagnosis is key. Please ensure your mechanic has ruled out other potential causes, such as wiring, sensor, or fuel system problems, before ordering.
What other relearns might be needed?
Depending on your vehicle and the repair, you may need to perform additional procedures after installation. These can include a crankshaft position variation relearn or entering injector flow rate information. These procedures require a professional-grade scan tool.