Restore Your Truck’s Brain and End Frustrating Engine Problems
As a technician with over two decades of experience, I’ve seen firsthand how a failing Engine Control Module (ECM) can turn a powerful workhorse like a 2012-2016 Silverado 3500 into a source of constant headaches. If you’re dealing with a persistent check engine light, rough idling, stalling, or bizarre transmission behavior, the root cause is often the very computer that’s supposed to be managing it all. This isn’t just an inconvenience; it affects your truck’s reliability, fuel economy, and safety. This replacement ECM, part number 12670335, is the definitive solution to get your truck back to factory-spec performance without the dealership price tag or hassle.
Case Study: A Tricky Diagnosis
I remember a 2014 Silverado 3500 with the 6.0L V8 that came into my shop. The owner was at his wit’s end. The truck would randomly lose power and sometimes stall at traffic lights, but there were no consistent trouble codes—just a generic U0100 ‘Lost Communication with ECM/PCM’ that would pop up intermittently. We checked grounds, wiring harnesses, and power feeds, but everything seemed fine. On a hunch, I monitored the ECM’s internal temperature and voltage data during a long test drive. I noticed erratic voltage drops right before each event. The ECM was failing internally under load. We replaced it with a VIN-programmed module just like this one. The installation was simple, and after a quick security relearn, the truck ran perfectly. It’s a classic example of how a faulty module can create ghost-like problems that are impossible to trace to a mechanical fault.
Is Your Silverado Acting Up? Common ECM Failure Signs
A failing computer can manifest in many ways. If you’re experiencing any of the following, a faulty ECM is a likely culprit. Proper diagnosis is always recommended, but these are tell-tale signs I see in the bay every week.
- ✔ Persistent Check Engine Light (CEL) that won’t go away.
- ✔ Engine stalling, stumbling, or running rough for no apparent reason.
- ✔ A complete no-start condition where the engine cranks but won’t fire up.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Stored diagnostic trouble codes (DTCs) such as P0601, P0606, or U0100.
- ✔ Communication errors with your scan tool.
The Smart Solution: Pre-Programmed for Your Truck
The single biggest hurdle when replacing a modern ECM is the programming. This module eliminates that problem entirely. We take your vehicle’s VIN and professionally flash the computer with the latest, most stable software updates directly from GM. This ensures that all factory parameters for your specific engine, transmission, and options are correctly loaded. You get a component that is truly ready for installation, saving you a costly trip to the dealership and hours of diagnostic headaches. This is the same process we use in our own repair facility to guarantee a successful and lasting repair for the 2012-2016 Silverado 3500 ECM.
A Straightforward Guide to Installation
Replacing the ECM on your Silverado is a job most DIYers can handle with basic tools. On these trucks, the module is typically located in the front left (driver’s side) of the engine compartment.
- Safety First: Always disconnect the negative terminal from your truck’s battery and wait 10-15 minutes for the system capacitors to discharge.
- Locate the ECM: Find the Engine Control Module on the driver’s side of the engine bay, usually mounted to the inner fender or firewall.
- Disconnect the Wiring: Carefully unlatch and remove the electrical connectors. Inspect them for any corrosion or damage.
- Remove the Old Module: Unbolt the mounting brackets holding the old ECM in place and remove it from the vehicle.
- Install the New ECM: Mount your new, pre-programmed ECM in the same location and secure it with the original hardware.
- Reconnect Everything: Firmly re-seat the electrical connectors until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn: In most cases, you will need to perform a simple security relearn procedure to sync the new ECM with your truck’s anti-theft system. This typically involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual or a reliable online resource for the exact procedure for your model year.
Verified Vehicle Compatibility
This ECM is a direct replacement for several original part numbers and fits a wide range of GM vehicles. Please verify your part number or contact us with your VIN to confirm compatibility. This module is guaranteed to fit the 2012-2016 Silverado 3500 ECM applications listed below, among others.
CRUZE 16 Electronic Control Module; VIN P (4th digit, Limited)
SONIC 12 Electronic Control Module; 1.4L
ELR 14-16 Electronic Control Module; gasoline, (LH rear engine compartment)
EXPRESS 3500 VAN 16 Electronic Control Module; (LH rear engine compartment), 4.8L
CRUZE 12 Electronic Control Module; 1.4L
CRUZE 15 Electronic Control Module; gasoline, ID 12668866
SONIC 15 Electronic Control Module; ID 12668866
TRAX 13-14 Electronic Control Module; 1.4L
SONIC 13 Electronic Control Module; ID 12643636
EXPRESS 3500 VAN 16 Electronic Control Module; (LH rear engine compartment), 6.0L
SAVANA 3500 VAN 16 Electronic Control Module; (LH rear engine compartment), 6.0L
EXPRESS 2500 VAN 16 Electronic Control Module; (LH rear engine compartment), 6.0L
SONIC 14 Electronic Control Module; (ID 12643636)
EXPRESS 2500 VAN 16 Electronic Control Module; (LH rear engine compartment), 4.8L
SILVERADO 2500 PICKUP 12-16 Electronic Control Module; (LH front engine compartment), 6.0L
SILVERADO 3500 PICKUP 12-16 Electronic Control Module; (LH front engine compartment), 6.0L
VOLT 11-15 Electronic Control Module; gasoline, (LH rear engine compartment)
SAVANA 2500 VAN 16 Electronic Control Module; (LH rear engine compartment), 4.8L
CRUZE 14 Electronic Control Module; gasoline
SAVANA 2500 VAN 16 Electronic Control Module; (LH rear engine compartment), 6.0L
SONIC 16 Electronic Control Module
CRUZE 13 Electronic Control Module
ENCORE 15 Electronic Control Module; (1.4L), ID 12643636
ENCORE 16 Electronic Control Module; (1.4L), VIN B (8th digit, opt LUV)
SAVANA 3500 VAN 16 Electronic Control Module; (LH rear engine compartment), 4.8L
SIERRA 2500 PICKUP 12-16 Electronic Control Module; (LH front engine compartment), 6.0L
SIERRA 3500 PICKUP 12-16 Electronic Control Module; (LH front engine compartment), 6.0L
TRAX 15-16 Electronic Control Module
SIERRA DENALI 2500 12-15 Electronic Control Module; (LH front engine compartment), 6.0L
SUBURBAN 3500 16 Electronic Control Module; (LH front engine compartment)
ENCORE 13-14 Electronic Control Module; (1.4L)
SPARK 14-15 Electronic Control Module; gasoline model
SIERRA DENALI 3500 12-16 Electronic Control Module; (LH front engine compartment), 6.0L
ENCORE 15 Electronic Control Module; (1.4L), ID 12668866
SONIC 15 Electronic Control Module; ID 12643636
This module is a direct replacement for the following part numbers: 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, 12692200.
How do I provide my VIN for programming?
How do I provide my VIN for programming?
It’s simple! After you complete your purchase, please send us a message with your vehicle’s 17-digit VIN. We cannot program and ship your module without it. You can typically find your VIN on your vehicle’s registration, insurance card, or on the driver’s side dashboard visible through the windshield.
Is this module difficult to install?
How do I provide my VIN for programming?
It’s simple! After you complete your purchase, please send us a message with your vehicle’s 17-digit VIN. We cannot program and ship your module without it. You can typically find your VIN on your vehicle’s registration, insurance card, or on the driver’s side dashboard visible through the windshield.
What is the difference between an ECM and a PCM?
How do I provide my VIN for programming?
It’s simple! After you complete your purchase, please send us a message with your vehicle’s 17-digit VIN. We cannot program and ship your module without it. You can typically find your VIN on your vehicle’s registration, insurance card, or on the driver’s side dashboard visible through the windshield.
Will this fix my check engine light?
How do I provide my VIN for programming?
It’s simple! After you complete your purchase, please send us a message with your vehicle’s 17-digit VIN. We cannot program and ship your module without it. You can typically find your VIN on your vehicle’s registration, insurance card, or on the driver’s side dashboard visible through the windshield.
What if my original part number is not on the interchange list?
How do I provide my VIN for programming?
It’s simple! After you complete your purchase, please send us a message with your vehicle’s 17-digit VIN. We cannot program and ship your module without it. You can typically find your VIN on your vehicle’s registration, insurance card, or on the driver’s side dashboard visible through the windshield.