Restore Your Vehicle’s Core Performance and Reliability
Is your Chevrolet, GMC, Cadillac, or other GM vehicle acting erratically? Dealing with a frustrating no-start condition, rough idling, or a check engine light that just won’t go away can bring your day to a halt. As a technician with over two decades of experience under the hood, I’ve seen countless drivers chase symptoms, replacing sensor after sensor, when the real culprit is the Engine Control Module (ECM)—the vehicle’s brain. This isn’t just a replacement part; it’s a direct solution to restore your vehicle’s factory-specified operation and get you back on the road with confidence.
This ECM, part number 12625455 (also compatible with 12629009), is the central command unit for your engine. It precisely controls fuel injection, ignition timing, and transmission shifting, ensuring optimal power, efficiency, and emissions. When it fails, the symptoms can be confusing and widespread. We take the guesswork and hassle out of the repair by programming this module specifically to your vehicle’s VIN before it ships. This means it arrives with the latest GM software updates already installed, saving you a costly and time-consuming trip to the dealership.
Case Study: A Tricky Diagnosis
I remember a 2009 Malibu that came into the shop with a phantom stalling issue. The owner had already replaced the fuel pump and crankshaft position sensor, but the car would still die randomly at stoplights. No consistent codes were stored, just a generic U0100 ‘Lost Communication with ECM’ every so often. After checking the wiring harness for integrity, we focused on the ECM itself. Internal circuit board failures, often caused by years of heat cycles and vibration, can lead to these intermittent problems that are a nightmare to diagnose. We installed a VIN-programmed ECM, performed the security relearn, and the problem was solved permanently. It’s a classic example of how tackling the core issue saves time and money in the long run.
Common Signs of a Failing ECM
If you’re experiencing any of the following, a faulty engine computer could be the cause. A proper diagnosis is always recommended, but these are tell-tale signs I’ve seen repeatedly in my shop:
- ✔ Check Engine Light: Persistent illumination, especially with codes like P0601 (Internal Control Module Memory Check Sum Error), P0606 (ECM/PCM Processor Fault), or various communication codes (U-codes).
- ✔ Engine Performance Issues: Noticeable loss of power, poor acceleration, and decreased fuel economy.
- ✔ Stalling or Rough Idle: The engine may stall for no apparent reason, either while driving or when stopped.
- ✔ Starting Problems: The vehicle may crank but refuse to start, or fail to crank at all.
- ✔ Erratic Transmission Shifting: The ECM plays a key role in telling the transmission when to shift, so harsh or incorrect shifting can point to a computer issue.
A Straightforward Guide to Installation
While professional installation is always an option, a confident DIYer can handle this replacement. The key is our VIN programming, which handles the most complex step for you.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post to prevent accidental contact.
- Locate the ECM: On most of the listed vehicles, the ECM is found in the engine bay, often on the driver’s side near the firewall, air filter box, or fender. Consult your vehicle’s service manual for the exact location.
- Disconnect and Remove: Carefully unplug the electrical connectors. These usually have locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket.
- Install the New Module: Bolt the new, pre-programmed ECM into place. Reconnect the electrical connectors, ensuring they click securely into position.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Security Relearn: This is a critical step. Even with programming, your vehicle’s anti-theft system needs to recognize the new ECM. The procedure is typically simple (e.g., turn the key to ‘ON’ for 10-15 minutes, then ‘OFF’, and repeat two more times), but check the specific relearn process for your model.
Will This Fit My Vehicle?
This module is guaranteed to fit a wide array of GM vehicles. Please match your part number (12625455 or 12629009) or verify your vehicle is on the list below. Providing your VIN at checkout ensures we send the correctly programmed part for a perfect fit.
CORVETTE 09 Electronic Control Module; (RH engine compartment), Base
ESCALADE 09-10 Electronic Control Module; (LH front engine compartment)
ESCALADE ESV 09-10 Electronic Control Module; (LH front engine compartment)
ESCALADE EXT 09-10 Electronic Control Module; (LH front engine compartment)
EXPRESS 1500 VAN 09 Electronic Control Module; (LH rear engine compartment), 5.3L
EXPRESS 2500 VAN 09 Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L
EXPRESS 3500 VAN 09 Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L
G6 09 Electronic Control Module; (LH front engine compartment), 3.5L or 3.9L
G8 09 Electronic Control Module; ID 12625455
HUMMER H2 09 Electronic Control Module; (LH front engine compartment)
IMPALA 09 Electronic Control Module; (lower part of air cleaner box), 3.5L or 3.9L
MALIBU 09 Electronic Control Module; 3.5L
SAVANA 1500 VAN 09 Electronic Control Module; (LH rear engine compartment), 5.3L
SAVANA 2500 VAN 09 Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L
SAVANA 3500 VAN 09 Electronic Control Module; (LH rear engine compartment), 4.8L or 6.0L
SIERRA 1500 PICKUP 09 Electronic Control Module; (LH front engine compartment), w/o hybrid option; w/o 4.3L
SIERRA 2500 PICKUP 09-10 Electronic Control Module; (LH front engine compartment), 6.0L
SIERRA 3500 PICKUP 09-10 Electronic Control Module; (LH front engine compartment), 6.0L
SIERRA DENALI 09-10 Electronic Control Module; (LH front engine compartment)
SILVERADO 1500 PICKUP 09 Electronic Control Module; (LH front engine compartment), w/o hybrid option; w/o 4.3L
SILVERADO 2500 PICKUP 09-10 Electronic Control Module; (LH front engine compartment), 6.0L
SILVERADO 3500 PICKUP 09-10 Electronic Control Module; (LH front engine compartment), 6.0L
SUBURBAN 1500 09-10 Electronic Control Module; (LH front engine compartment)
SUBURBAN 2500 09-10 Electronic Control Module; (LH front engine compartment)
TAHOE 09-10 Electronic Control Module; (LH front engine compartment), w/o hybrid option
VUE 10 Electronic Control Module; 3.5L
YUKON 09-10 Electronic Control Module; (LH front engine compartment), w/o hybrid option
YUKON XL 1500 09 Electronic Control Module; (LH front engine compartment)
YUKON XL 2500 09-10 Electronic Control Module; (LH front engine compartment)
Why do I have to provide my VIN?
Why do I have to provide my VIN?
Your Vehicle Identification Number (VIN) allows us to program the ECM with the exact software and calibrations your specific vehicle requires. This ensures perfect compatibility with your engine, transmission, and other options, eliminating the need for a dealership visit for programming.
Is this a simple plug-and-play installation?
It is very close. Because we pre-program the module, the most difficult part is already done. However, you will need to perform a security relearn procedure after installation so your vehicle’s anti-theft system recognizes the new ECM. This procedure is straightforward and can typically be done without special tools.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the ECM (like codes P0601-P0606), then yes, this part is the correct fix. However, if the light is on due to a faulty sensor or other component, you will still need to address that separate issue.
How can I be sure my original ECM is the problem?
A thorough diagnosis is key. This includes checking for consistent ECM-related fault codes, verifying power and ground signals to the module, and ensuring the wiring harness is intact. If other potential causes like sensors and actuators have been ruled out, the ECM is the likely culprit, especially with the symptoms listed above.
What’s the difference between part numbers 12625455 and 12629009?
These are compatible part numbers from GM. Functionally, they are the same and fully interchangeable. When you order, you will receive a module that works for either part number, programmed specifically for your vehicle.