Restore Peak Performance to Your GM Truck or SUV
Is your truck or SUV suffering from frustrating issues like a persistent check engine light, stalling, poor fuel economy, or a no-start condition? These are classic signs of a failing Engine Control Module (ECM), the electronic brain that manages your vehicle’s engine performance, fuel delivery, and ignition timing. A faulty ECM can cripple your vehicle, leaving you stranded and facing a complex repair. This direct-fit ECM, part number 12625455, is the definitive solution to restore your vehicle’s reliability and drivability.
From the Diagnostic Bay
We had a 2009 Sierra 2500 in the shop that was driving the owner crazy. It would randomly misfire and stall, but only after it was fully warmed up. We checked everything—plugs, coils, fuel pressure—and couldn’t find a mechanical fault. After hours of diagnostics, we hooked up a scope to the injector drivers and saw the signal dropping out intermittently from the ECM. A new, programmed module fixed it instantly. Sometimes, the ghost in the machine is the machine’s brain itself.
Symptoms of a Failing Engine Computer
- ✔ Persistent Check Engine Light (CEL) with various fault codes.
- ✔ Unexplained engine stalling, hesitation, or misfiring.
- ✔ Noticeable decrease in power and acceleration.
- ✔ Worsening fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Intermittent or complete no-start condition where the engine cranks but won’t fire.
- ✔ Inability for scan tools to communicate with the engine module.
The Right Solution: A Pre-Programmed 2009-2010 Sierra 3500 ECM
Don’t settle for a generic, unprogrammed module that will require an expensive trip to the dealership. We take the guesswork and hassle out of the repair process. When you purchase this ECM, we use the Vehicle Identification Number (VIN) you provide to flash the unit with the latest, most stable GM-certified software specific to your vehicle’s configuration. This ensures that your engine, transmission, emissions systems, and all related components function in perfect harmony, just as the manufacturer intended. This process often corrects underlying software issues present in the original factory programming.
This module is a direct replacement for part numbers 12625455 and 12629009 and fits a wide range of General Motors vehicles from 2009-2010, including the Silverado, Suburban, Tahoe, Escalade, Savana, and more. Installation is straightforward for any experienced DIYer or professional technician. Simply disconnect the battery, remove the old module, install the new one, and reconnect the battery. In some cases, a simple security or crankshaft variation (CASE) relearn procedure may be required, which can be performed with most professional-grade scan tools.
Frequently Asked Questions
Why is VIN programming so important for this ECM?
The VIN contains critical information about your truck’s specific options, engine, transmission, and emissions equipment. Programming the ECM with your VIN ensures all systems communicate and function exactly as the factory intended, preventing compatibility issues.
Will I need to take my truck to the dealer after installing this?
In most cases, no. This ECM comes ready to install. However, some vehicles may require a security relearn procedure (often called a key relearn) or a CASE relearn, which can be performed by many independent shops or with an advanced DIY scan tool.
What’s the difference between an ECM, ECU, and PCM?
These terms are often used interchangeably. ECM (Engine Control Module) and ECU (Engine Control Unit) are the same. PCM (Powertrain Control Module) is a more integrated unit that may control both the engine and the transmission. For your vehicle, this part serves as the primary engine controller.
How can I be sure my old ECM is the problem?
A definitive diagnosis requires a professional scan tool to check for specific ECM-related fault codes (like internal processor failure) and to rule out sensor or wiring issues. The symptoms listed on this page are strong indicators of a potential ECM failure.
Does this unit replace part number 12629009?
Yes, this ECM is a direct, fully compatible replacement for original part numbers 12625455 and 12629009, ensuring proper function and fitment.