Restore Your GM Van or Truck’s Performance and Reliability
Is your Savana, Express, Silverado, or Sierra plagued by frustrating engine problems? Issues like random stalling, a persistent check engine light, poor fuel mileage, or a no-start condition can often be traced back to a failing Engine Control Module (ECM). As a technician with over two decades of experience, I’ve seen firsthand how a faulty ECM can wreak havoc on a vehicle’s entire operation. This isn’t just a part; it’s the central computer for your engine, and when it fails, your vehicle’s reliability is gone.
We offer a straightforward, dependable solution. This genuine GM service ECM, part number 12653246, arrives at your door programmed specifically for your vehicle. We use your Vehicle Identification Number (VIN) to load the latest, most stable software updates from General Motors. This critical step ensures seamless communication with your vehicle’s other modules, restoring factory performance and eliminating the need for an expensive trip to the dealership for programming. Get your work van or truck back on the road quickly and confidently.
From the Diagnostic Bay: The Ghost in the Machine
A local contractor brought in his 2011 Express 1500 work van with a problem that was costing him money every day. It would randomly stall at traffic lights and sometimes refuse to restart for 10-15 minutes. No specific sensor codes were present, just a generic P0606 (ECM/PCM Processor Fault) that would come and go. After verifying the wiring harness and power/ground circuits were solid, we knew the issue was internal to the computer. Instead of a costly dealer replacement, he ordered one of our VIN-programmed modules. The installation took less than 30 minutes, and after a quick security relearn, the van ran perfectly. The ghost was gone. That was two years ago, and his van is still running strong, a testament to getting the right, correctly programmed part the first time.
Is Your Vehicle Showing These Symptoms?
- ✔ Check Engine Light is illuminated with codes like P0601 (Internal Control Module Memory Check Sum Error), P0606 (ECM/PCM Processor Fault), or other communication errors.
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling, especially when coming to a stop or at idle.
- ✔ Noticeable decrease in fuel economy.
- ✔ The transmission shifts harshly or erratically.
- ✔ Misfires or rough running that can’t be traced to plugs, coils, or injectors.
A Straightforward Guide to Installation
Replacing your Savana 1500 ECM is a manageable job for a DIYer or any professional technician. Follow these general steps for a successful installation.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 10 minutes before proceeding.
- Locate the ECM: On Savana and Express vans, the ECM is in the left-hand rear of the engine compartment. On Silverado and Sierra pickups, it’s located on the left-hand front side, typically under or near the battery tray.
- Disconnect the Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. Never force them. Inspect the pins for any corrosion or damage.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket.
- Install the New Module: Bolt your new, pre-programmed ECM into place. Reconnect the wiring harness connectors, ensuring they click securely into position.
- Reconnect the Battery: Reattach the negative battery terminal.
- Perform Security Relearn (CRITICAL): You must perform a security relearn procedure (often called a Passlock or anti-theft relearn) for the vehicle to start. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. Consult your vehicle’s service information for the exact procedure.
Verified Vehicle Compatibility
This module is a direct-fit replacement for the following vehicles equipped with the 4.3L V6 engine. It is compatible with service numbers 12635043, 12639471, and 12653246.
- 2010-2014 GMC Savana 1500 Van (4.3L)
- 2010-2014 Chevrolet Express 1500 Van (4.3L)
- 2010-2013 Chevrolet Silverado 1500 Pickup (4.3L)
- 2010-2013 GMC Sierra 1500 Pickup (4.3L)
Frequently Asked Questions
Do I need to do any programming myself?
Do I need to do any programming myself?
No. We handle all the programming before we ship the part. We flash the module with the latest GM software using the VIN you provide during checkout. It arrives ready for installation and the security relearn procedure.
Where do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot program or ship your module without it, so please provide it promptly to avoid delays.
What is the security relearn procedure?
This is a required anti-theft system reset that pairs the new ECM to your vehicle. It’s simple and requires no tools. The most common method is the ’10-minute key cycle’ procedure, which you can easily find online or in your vehicle’s service manual. The engine will not start until this is completed.
Is this a used part?
This is a genuine, tested OEM-quality part that has been inspected and prepared for service. We load it with vehicle-specific software to ensure it functions as a direct replacement for your original, failed module.
How do I know if my ECM is really the problem?
While the symptoms listed are strong indicators, a definitive diagnosis is key. Common ECM failure codes like P0601 or P0606 are clear signs. It’s also wise to check for good power and ground signals at the ECM connector and ensure no other components (like sensors or wiring) are causing the issue before ordering a replacement.