Restore Peak Performance to Your GM Vehicle
Is your workhorse van, truck, or SUV suddenly unreliable? A faulty Engine Control Module (ECM) can be the hidden culprit behind a host of frustrating issues, from a simple check engine light to a vehicle that refuses to start. As the central computer of your vehicle, the ECM manages everything from fuel mixture and ignition timing to transmission shifting. When it fails, the symptoms can be unpredictable and difficult to diagnose. This is the definitive solution for your 2009 Express 3500 Engine Computer needs and a wide range of other GM vehicles.
Forget the expensive dealership visit and the hassle of towing your vehicle for programming. We take care of the hard part for you. Simply provide your Vehicle Identification Number (VIN) during checkout, and our technicians will program this module with the latest GM-certified software specific to your vehicle. It arrives at your door ready for a straightforward, plug-and-play installation, getting you or your customer back on the road with confidence.
From the Diagnostic Bay
I remember a 2009 Savana 3500 work van that came into my shop with a maddeningly intermittent stalling problem. The driver said it would die at stoplights, then restart fine. No consistent codes, just a random P0601 (Internal Control Module Memory Check Sum Error) that would pop up now and then. We checked grounds, wiring, and sensors for two days. On a hunch, I tapped the ECM with a screwdriver handle while the engine was running, and it immediately stalled. The internal board had a micro-fracture. We installed one of these VIN-programmed modules, and the van has been running solid for that plumbing company ever since. It’s a reminder that sometimes the ‘brain’ is the source of the ghost-in-the-machine problems.
Is Your GM Vehicle Exhibiting These ECM Failure Signs?
- ✔ Check Engine Light is on with codes like P0601, P0602, P0606, or U0100.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drop in fuel economy.
- ✔ Rough or erratic idling and stalling.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Communication errors with your scan tool.
- ✔ Misfires or loss of power under acceleration.
A Straightforward Guide to Installation
- ✔ Safety First: Always disconnect the negative terminal from your vehicle’s battery before beginning work.
- ✔ Locate the ECM: On most GM trucks and SUVs, the ECM is in the left-hand (driver’s side) front engine compartment. On Express and Savana vans, it’s typically located in the left-hand rear of the engine compartment.
- ✔ Disconnect Connectors: Carefully release the locking tabs on the wiring harness 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. There are typically a few bolts holding it in place.
- ✔ Install the New Module: Mount your new, pre-programmed ECM onto the bracket and secure the bolts.
- ✔ Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect your battery terminal.
- ✔ Final Check: Start the vehicle. It may take a moment to idle smoothly as it completes its initial learning cycle. A security relearn procedure may be required, which typically involves cycling the key.
By replacing your faulty module with this pre-programmed 2009 Express 3500 Engine Computer, you are restoring the vehicle’s core operational logic. This ensures all related components function as the manufacturer intended, providing reliable performance for years to come.
Will This Fit My Vehicle?
This module is a direct replacement for part numbers 12625455 and 12629009 and fits a wide variety of GM models. Please verify your vehicle is on this list and that the options match.
SILVERADO/SIERRA 1500 PICKUP 09 (LH front engine), w/o hybrid, w/o 4.3L
SILVERADO/SIERRA 2500 & 3500 PICKUP 09-10 (LH front engine), 6.0L
AVALANCHE 1500 09-10 (LH front engine)
SUBURBAN 1500/2500 09-10 (LH front engine)
TAHOE/YUKON 09-10 (LH front engine), w/o hybrid
YUKON XL 1500/2500 09-10 (LH front engine)
ESCALADE, ESV, EXT 09-10 (LH front engine)
HUMMER H2 09 (LH front engine)
SAVANA 1500 VAN 09 (LH rear engine), 5.3L
SAVANA 2500/3500 VAN 09 (LH rear engine), 4.8L or 6.0L
CORVETTE 09 (RH engine), Base
G6 09 (LH front engine), 3.5L or 3.9L
G8 09 ID 12625455
IMPALA 09 (air cleaner box), 3.5L or 3.9L
MALIBU 09 3.5L
VUE 10 3.5L
…and more. Please match your part number or contact us with your VIN.
Frequently Asked Questions
Why do you need my VIN to program the module?
Your Vehicle Identification Number (VIN) contains critical information about your vehicle’s specific options, engine, transmission, and emissions equipment. We use the VIN to load the exact, correct GM software, ensuring the module communicates perfectly with your vehicle’s other systems right out of the box.
Is this part difficult to install for a DIYer?
Not at all. For most models, the ECM is easily accessible in the engine bay. The installation involves disconnecting the battery, unplugging the old module, swapping it with the new one, and reconnecting everything. It typically requires only basic hand tools and about 30-60 minutes.
What is an ECM and what does it do?
The Engine Control Module (ECM) is your vehicle’s main computer, or ‘brain’. It takes data from sensors all over the engine and vehicle to control fuel injection, spark timing, idle speed, and emissions systems for optimal performance and efficiency.
Do I need to perform any other steps after installation?
In most cases, no. The module is sent ready for installation. Some GM vehicles may require a simple security relearn procedure (often called a ‘key cycle relearn’), which takes a few minutes and does not require special tools. Instructions can be easily found online or we can assist you.
My original part number is 12629009. Will this work?
Yes. Part number 12625455 is a fully compatible replacement for 12629009. We ensure the software loaded via your VIN matches your vehicle’s requirements perfectly, regardless of which of these two part numbers was originally installed.