Get Your GM Van or Truck Back to Peak Performance
Is your 2016 Express 3500 Van suffering from frustrating issues like intermittent stalling, a persistent check engine light, or erratic performance? As a technician with over two decades of experience, I’ve seen these symptoms countless times, and they often point directly to a failing Engine Control Module (ECM). The ECM is the brain of your vehicle, and when it starts to falter, it can cause a cascade of problems that leave you stranded and facing expensive diagnostic bills. This isn’t just an inconvenience; for a work van, it’s lost time and money.
This replacement Engine Control Module is the definitive solution. We take the guesswork and hassle out of the repair by pre-programming the module specifically for your vehicle using your VIN. This means it arrives at your door with the latest factory software from GM, ready for installation. You get a reliable part that restores original performance, fuel efficiency, and drivability without the need for a costly trip to the dealership for programming.
A Technician’s Notebook: The Case of the Unreliable Work Van
A local contractor brought in his Express 3500 work van with a ghost in the machine. It would randomly refuse to start, especially on hot days, and sometimes the transmission would shift hard for no reason. He’d already replaced the battery and checked the fuel pump. The scanner showed a U0100 ‘Lost Communication with ECM/PCM’ code, a classic sign of an internal module failure. The heat was causing a circuit board inside the original ECM to fail intermittently. We replaced it with one of our VIN-programmed modules. The installation was done in under 30 minutes, and the van fired up instantly. All the weird electrical gremlins were gone. He was back on the job the same afternoon, having saved hundreds in dealer fees and, more importantly, avoided a full day of lost work.
Common Signs of a Failing Engine Computer
If you’re experiencing any of the following, a faulty ECM could be the root cause. In my shop, these are the most frequent indicators I see:
- ✔ The Check Engine Light is on, often with communication-related Diagnostic Trouble Codes (DTCs) like U0100, or internal processor fault codes like P0601 or P0606.
- ✔ Your engine cranks but refuses to start.
- ✔ The vehicle stalls unexpectedly while driving or idling.
- ✔ A noticeable drop in fuel economy.
- ✔ The transmission shifts harshly or at the wrong times.
- ✔ Failure to pass state emissions testing.
A Straightforward Guide to Installation
Installing your new, pre-programmed 2016 Express 3500 ECM is a job most DIYers or any professional mechanic can handle. Follow these steps for a smooth installation:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the Module: On the 2016 Express and Savana vans, the ECM is typically located in the engine compartment, on the driver’s side near the firewall or inner fender.
- Disconnect and Remove: Carefully unlatch and remove the electrical connectors. Be gentle, as the plastic clips can become brittle over time. Then, unbolt the old module from its mounting bracket.
- Install the New ECM: Mount the new module securely in the bracket and firmly reconnect the electrical harnesses. Ensure they click into place to confirm a solid connection.
- Reconnect Power: Re-attach the negative battery terminal and tighten it securely.
- Security Relearn Procedure: In many GM vehicles, you may need to perform a simple security relearn procedure to sync the new ECM with your vehicle’s anti-theft system. This usually involves turning the key to the ‘ON’ position for 10-15 minutes. Consult your owner’s manual or a quick online search for your specific model’s procedure.
Verified Fitment Across a Wide Range of GM Vehicles
While this is a direct-fit solution for the 2016 Express 3500 ECM, this versatile module is also compatible with a vast array of other GM cars, trucks, and SUVs. Please verify your part number and check the list below to ensure compatibility.
This module is a direct replacement for the following part numbers: 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, 12692200.
Compatible Models Include:
- Buick Encore (2013-2016)
- Cadillac ELR (2014-2016)
- Chevrolet Cruze (2012-2016)
- Chevrolet Sonic (2012-2016)
- Chevrolet Spark (2014-2015)
- Chevrolet Trax (2013-2016)
- Chevrolet Volt (2011-2015)
- GMC/Chevy Express & Savana Vans 2500/3500 (2016) with 4.8L or 6.0L engines
- GMC/Chevy Silverado & Sierra Pickups 2500/3500 (2012-2016) with 6.0L engines
- GMC/Chevy Sierra Denali 2500/3500 (2012-2016) with 6.0L engines
- Chevrolet Suburban 3500 (2016)
Frequently Asked Questions
Frequently Asked Questions
Do I need to program or flash this ECM?
No. We handle all the programming for you before shipment. It arrives ready to install. This service saves you the time, cost, and hassle of a dealership visit.
What information do you need from me to program it?
After you place your order, you will need to provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). This ensures we load the exact correct software for your specific vehicle configuration.
Is this a simple plug-and-play installation?
Yes, for the most part. Once programmed, you just need to swap the physical module. Some GM vehicles may require a simple, key-on security relearn procedure that takes about 10-15 minutes to complete and requires no special tools.
Will this fix my check engine light?
If your check engine light is caused by a defective ECM (e.g., codes U0100, P0601), then yes, this will resolve the issue. However, if the light is on for another reason, like a bad oxygen sensor, that separate issue will still need to be addressed.
How can I be sure my old ECM is the problem?
The symptoms listed above are strong indicators. The most definitive way is to have a professional mechanic diagnose the issue. If communication with the scan tool is impossible or you have internal processor fault codes, the ECM is the most likely culprit.
Which part numbers does this module replace?
This unit is a direct replacement for several part numbers, including 12668866, 12668994, 12643636, 12663405, 12670335, 22819494, and 12692200.