Restore Your Truck’s Core Performance and Reliability
As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing Engine Control Module (ECM) can bring even the toughest trucks to a dead stop. Your 2012-2016 Sierra Denali 2500 is a powerhouse, but its muscle is useless without its brain. The ECM, or Powertrain Control Module (PCM), is that brain, managing everything from fuel injection and spark timing to transmission shifts and emissions. When it fails, you’re faced with frustrating, often intermittent, problems that can be a nightmare to diagnose. This isn’t just a replacement part; it’s a complete, hassle-free solution to get your truck running right again.
We take the biggest headache out of the repair process: the programming. Dealerships can charge hundreds for this service alone, not to mention the cost of a tow and the time your truck is out of commission. We eliminate that. Simply provide your vehicle’s VIN during checkout, and our experts will flash this module with the latest, most stable GM factory software specific to your truck. It arrives at your door ready for installation, saving you significant time and money.
A Technician’s Notebook: The Ghost in the Machine
I remember a 2014 Silverado 2500 with the 6.0L—same platform as your Sierra—that came into my bay on a tow hook. The owner was at his wit’s end. The truck would randomly stall at traffic lights and sometimes refuse to start for an hour. He’d already replaced the battery and alternator. Other shops couldn’t find the problem because, of course, it ran perfectly whenever they had it. After hooking up my diagnostic scanner and digging into the live data, I noticed momentary communication dropouts with the TCM and BCM. The key clue was a stored history code: P0601 – Internal Control Module Memory Check Sum Error. This code is a death sentence for an ECM. The internal processor was failing intermittently. We installed a VIN-programmed 2012-2016 Sierra Denali 2500 ECM, performed the 10-minute security relearn, and the truck never had the issue again. It’s a classic failure mode, and this module is the definitive fix.
Is Your Truck Showing These Symptoms?
A failing ECM can manifest in many ways. If you’re experiencing any of the following, a faulty engine computer is a likely culprit:
- ✔ Check Engine Light is on with communication codes (like U0100) or internal processor codes (P0601, P0606, P062F).
- ✔ Engine cranks but refuses to start.
- ✔ Intermittent stalling or rough idling for no apparent reason.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Misfire codes that persist even after replacing spark plugs and coils.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Installation
This repair is well within the reach of a capable DIYer. Since the programming is done, the physical swap is all that’s left. For most trucks like the Sierra/Silverado, the process is simple:
- Safety First: Disconnect the negative terminal from your truck’s battery.
- Locate the ECM: On most 2012-2016 GM HD trucks, the ECM is located in the front left (driver’s side) of the engine compartment, near the battery or airbox.
- Disconnect Connectors: Carefully release the locking levers and unplug the wiring harness connectors from the old module. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed ECM into place and securely reconnect the wiring harnesses. Ensure the levers click and lock.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Security Relearn (If Necessary): Turn the key to the ‘ON’ position (don’t start the engine) for 10-15 minutes. The ‘Security’ light on the dash should turn off. Turn the key off for 10 seconds, then start the engine. It’s that simple.
Verified Vehicle Compatibility
This engine control module is a direct replacement for a wide range of General Motors vehicles, ensuring broad compatibility. While this listing is focused on the 2012-2016 Sierra Denali 2500 ECM, it also fits the models below. It directly replaces part numbers 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, and 12692200.
SIERRA/SILVERADO 2500/3500 (12-16) 6.0L
SIERRA DENALI 2500/3500 (12-16) 6.0L
EXPRESS/SAVANA 2500/3500 (16) 4.8L & 6.0L
SUBURBAN 3500 (16)
SUVs & Cars:
CRUZE (12-16) 1.4L & Gasoline
SONIC (12-16) 1.4L
TRAX (13-16) 1.4L
ENCORE (13-16) 1.4L
VOLT (11-15) Gasoline
ELR (14-16) Gasoline
SPARK (14-15) Gasoline
Do I need to do any additional programming or flashing?
Do I need to do any additional programming or flashing?
No. The main benefit of our service is that we program the module to your vehicle’s specific VIN before we ship it. This handles the critical software calibration, saving you a trip to the dealership.
What information do you need from me?
After you complete your purchase, you will need to provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). We cannot program and ship your part without it.
Is this a simple plug-and-play installation?
For most vehicles, yes. After the physical installation, you may need to perform a simple ‘Security Relearn’ procedure which involves leaving the key in the ‘ON’ position for about 10-15 minutes. This allows the ECM to sync with your vehicle’s anti-theft system. No special tools are required.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the ECM (common codes P0601-P0606) or a related communication error, then yes, this module will resolve the issue. It’s crucial to ensure the ECM is the root cause of the problem before ordering.
Where can I find my VIN?
Your VIN can be found on a metal tag on the driver’s side of the dashboard (visible through the windshield), on the driver’s side door jamb sticker, and on your vehicle’s registration and insurance documents.