Restore Your Van’s Performance and Reliability
Is your Chevrolet Express or GMC Savana van running poorly? A failing Engine Control Module (ECM) is often the culprit behind a host of frustrating issues, from a persistent check engine light and rough idling to stalling and even a no-start condition. The ECM is the brain of your vehicle’s engine, managing everything from fuel injection and ignition timing to emissions control. When it fails, the entire system suffers. This replacement Engine Control Module, part number 12639471, is the definitive solution to get your workhorse back on the road, operating as it should.
We had a 2012 Express 1500 work van come into the shop with a complaint of intermittent stalling. The driver said it would happen randomly, sometimes at a stoplight, sometimes on the highway. There were no consistent codes, just a history of random misfires. We checked fuel pressure, spark, and sensors—everything looked fine. After hours of chasing ghosts, we hooked up a scope to the injector drivers coming out of the ECM. We saw the signal drop out for a split second, just before the engine would stumble. It was a classic case of an internal ECM fault that only showed up under specific thermal conditions. Swapping in a pre-programmed ECM like this one solved the problem instantly, saving the owner from what could have been a dangerous stall in traffic.
Common Symptoms of a Failing ECM
- ✔ Persistent Check Engine Light (CEL) with codes like P0601, P0602, P0606, or U0100.
- ✔ Unexplained drop in fuel economy.
- ✔ Engine misfiring, stumbling, or running rough.
- ✔ Intermittent or complete no-start condition where the engine cranks but won’t fire.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication issues with diagnostic scan tools.
- ✔ Stalling for no apparent reason.
Why Choose Our 2010-2014 Express 1500 ECM?
This isn’t just a part in a box; it’s a complete, ready-to-install solution. The biggest hurdle in replacing a modern ECM is the need for expensive, dealer-specific programming. We eliminate that step entirely. Upon purchase, simply provide us with your vehicle’s 17-digit Vehicle Identification Number (VIN). Our technicians will then flash the module with the latest, most stable GM-certified software specific to your van. This ensures that all factory performance parameters, bug fixes, and operational improvements are loaded and ready to go.
This plug-and-play convenience means you can avoid a costly trip to the dealership and the associated programming fees. The module is a direct-fit replacement for the original, guaranteeing a straightforward installation. It’s the most efficient and cost-effective way to restore your vehicle’s critical engine management system.
Guaranteed Fitment for 4.3L Engines:
- ✔ 2010-2014 Chevrolet Express 1500 Van
- ✔ 2010-2014 GMC Savana 1500 Van
- ✔ 2010-2013 Chevrolet Silverado 1500 Pickup
- ✔ 2010-2013 GMC Sierra 1500 Pickup
This module directly replaces the following GM service numbers:
12635043, 12639471, 12653246
Installation Note: On vans, the ECM is typically located in the left-hand rear of the engine compartment. On pickups, it’s found on the left-hand front, under the battery tray. While the unit is plug-and-play, some vehicles may require a simple security relearn procedure or a Crankshaft Variation (CASE) relearn, which can be performed with many professional-grade scan tools.
Frequently Asked Questions
Do I need to have this ECM programmed by a dealer?
No. We handle all the programming for you before we ship the part. Simply provide your vehicle’s VIN during checkout, and it will arrive ready to install.
What information do you need from me?
We only need your 17-digit Vehicle Identification Number (VIN). This allows us to load the exact correct GM software for your vehicle’s specific configuration.
Is this part difficult to install?
The physical installation is straightforward. You’ll need to disconnect the battery, then unplug the electrical connectors and unbolt the old ECM. The new one bolts in the same way. Some vehicles may require a security relearn procedure, which is a simple process you can often do yourself.
Will this fix my check engine light?
If your check engine light is caused by an internal failure of the ECM (common codes include P0601-P0606), then this replacement module will solve the problem. It is crucial to properly diagnose the issue before ordering.
What is a CASE Relearn?
A Crankshaft Variation (CASE) Relearn is a procedure that synchronizes the new ECM with your engine’s crankshaft position sensor. It helps the computer detect misfires accurately. While not always required, it is recommended for optimal performance and can be done by any professional shop with a capable scan tool.