Restore Your Truck’s Reliability and Performance
Is your 2012-2016 Sierra 3500 letting you down with a persistent check engine light, rough idling, or a frustrating no-start condition? These are classic signs that the brain of your engine—the Engine Control Module (ECM)—is failing. Over time, heat cycles, vibrations, and electrical shorts can corrupt the module’s internal circuits, leading to a host of performance issues. This isn’t just an annoyance; a faulty ECM can affect fuel economy, emissions, and the overall health of your powertrain. Don’t let a bad module sideline your workhorse truck. This direct-fit replacement ECM is the reliable, straightforward solution you need.
We take the guesswork and high dealership costs out of the equation. Each 2012-2016 Sierra 3500 ECM is professionally programmed to your truck’s specific Vehicle Identification Number (VIN) before it ships. This means it arrives loaded with the latest GM factory software updates, ensuring optimal communication with all your vehicle’s systems. You get a component that’s ready for installation right out of the box, eliminating the need for expensive programming tools or a trip to the dealer. Restore the crisp throttle response, stable idle, and dependable power you expect from your Sierra HD.
Common Signs of a Failing ECM
- ✔ Check Engine Light is illuminated with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (ECM/PCM Processor Fault).
- ✔ Engine cranks but refuses to start.
- ✔ Unexplained stalling or stumbling, especially when warm.
- ✔ Noticeable decrease in fuel mileage.
- ✔ Rough or erratic engine idle.
- ✔ Hesitation or poor acceleration.
- ✔ Transmission shifting issues or communication loss codes (like U0100).
Case Study: A Tricky Diagnosis
A customer brought in a 2014 Sierra 2500 with the 6.0L V8, complaining of an intermittent stall that no one could figure out. It would only happen after driving for 30+ minutes and would restart after cooling down. There were no hard codes, just a history of random communication faults. After verifying the fuel pressure and ignition systems were solid, I focused on the ECM. On a long test drive with a scope attached, I saw the 5-volt reference signal to the throttle body position sensor drop out just before it stalled. The heat was causing an internal failure in the ECM. Replacing the module with a quality, pre-programmed unit like this one solved the problem permanently. It’s a great example of how a failing 2012-2016 Sierra 3500 ECM can cause ghost-like issues that are tough to pin down without experience.
A Straightforward Guide to Installation
- ✔ Safety First: Disconnect the negative terminal from your truck’s battery and secure it away from the post to prevent accidental reconnection.
- ✔ Locate the ECM: On your Sierra 3500, the ECM is typically found in the engine bay, on the driver’s side near the fender or firewall.
- ✔ Disconnect the Harnesses: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Avoid pulling on the wires themselves.
- ✔ Remove the Old Module: Unbolt the old ECM from its mounting bracket. Keep the hardware, as you may need to reuse it.
- ✔ Install the New ECM: Mount your new, pre-programmed ECM onto the bracket and secure it with the bolts.
- ✔ Reconnect Everything: Plug the electrical harnesses firmly back into the new module until they click into place. Reconnect the negative battery terminal.
- ✔ Final Step: Some vehicles may require a security relearn procedure, which can often be done without special tools. A common method is to turn the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeat this cycle three times before starting the engine. Consult your vehicle’s service information for specifics.
Verified Vehicle Compatibility
This Engine Control Module is a direct replacement for part number 12670335 and interchanges with 12668866, 12668994, 12643636, 12663405, 22819494, and 12692200. It is guaranteed to fit the following vehicles with the specified options:
SIERRA 2500 PICKUP 12-16 (6.0L)
SIERRA 3500 PICKUP 12-16 (6.0L)
SIERRA DENALI 2500 12-15 (6.0L)
SIERRA DENALI 3500 12-16 (6.0L)
SAVANA 2500/3500 VAN 16 (4.8L, 6.0L)
Chevrolet Trucks & Vans:
SILVERADO 2500/3500 PICKUP 12-16 (6.0L)
SUBURBAN 3500 16
EXPRESS 2500/3500 VAN 16 (4.8L, 6.0L)
Other GM Models:
BUICK ENCORE 13-16 (1.4L)
CADILLAC ELR 14-16
CHEVROLET CRUZE 12-16 (Gasoline)
CHEVROLET SONIC 12-16 (1.4L)
CHEVROLET SPARK 14-15 (Gasoline)
CHEVROLET TRAX 13-16
CHEVROLET VOLT 11-15
Frequently Asked Questions
Frequently Asked Questions
Do I need to do any programming myself?
No. We handle all the programming for you. Simply provide your vehicle’s VIN during or after checkout, and we will flash the module with the latest GM software specific to your truck before shipping.
Where do I find my VIN?
Your 17-digit VIN can be found on your vehicle’s registration, insurance card, or on the driver’s side of the dashboard, visible through the windshield.
Is this a difficult part to install for a DIYer?
Not at all. For most models, it’s a simple unbolt-and-unplug process. As long as you disconnect the battery first, it’s one of the more straightforward electronic component replacements you can do.
Will this fix my check engine light?
If the check engine light is caused by a faulty ECM (confirmed by diagnostic trouble codes like P0601, P0606, etc.), then yes, this part is the correct solution. It’s always best to have the vehicle properly diagnosed first.
What is the difference between an ECM and a PCM?
The terms are often used interchangeably. ECM stands for Engine Control Module, while PCM stands for Powertrain Control Module. In most modern vehicles, a single PCM controls both the engine and transmission, but mechanics and parts suppliers often still call it an ECM.
Do I need to send my old part back?
This listing does not require a core return. You can keep or responsibly dispose of your old module.