Restore Peak Performance to Your Vehicle’s Engine
Is your Cadillac, Corvette, or Hummer suffering from frustrating and unpredictable issues like stalling, rough idling, a persistent Check Engine Light, or a complete no-start condition? These are classic signs of a failing Engine Control Module (ECM), the central computer that governs your vehicle’s performance. When it falters, it can feel like you’re chasing ghosts. This replacement Engine Control Module is the definitive solution, arriving at your door fully programmed with the latest GM software updates, tailored specifically to your vehicle’s VIN.
A Technician’s Notebook: The Intermittent No-Start Nightmare
I once had a 2009 Cadillac STS in my bay that was driving the owner crazy. It would start perfectly for a week, then refuse to start for two days, with no rhyme or reason. The battery was new, the starter was fine, but the scan tool would intermittently show a U0100 ‘Lost Communication with ECM’ code. After checking all the wiring and grounds, we isolated the problem to an internal fault in the original ECM. The customer was worried about a massive dealership bill for a new module and programming. We provided a pre-programmed unit just like this one. He swapped it in his driveway in under an hour, and the car has started flawlessly ever since. It’s a repair that saves both time and money.
Is Your Vehicle Showing These Telltale Signs?
A failing ECM can manifest in numerous ways. If you’re experiencing any of the following, it’s a strong indicator that your engine’s computer needs attention:
- ✔ Check Engine Light is on with communication error codes (e.g., U0100) or internal processor fault codes (e.g., P0601, P0606).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained stalling, especially when coming to a stop or at idle.
- ✔ Noticeable decrease in fuel economy.
- ✔ Poor engine performance, hesitation, or misfiring.
- ✔ Erratic or harsh transmission shifting.
- ✔ Other warning lights on the dash may illuminate without a clear cause.
Your Straightforward Installation Guide
Replacing your ECM is a manageable task for a confident DIYer or a quick job for any professional mechanic. Our VIN programming service makes it a true plug-and-play process, with no additional dealer visit required.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait 10-15 minutes to allow all systems to discharge fully.
- Locate the ECM: The module’s location varies by model (see fitment list). It could be on the firewall, in the engine compartment, or near the air cleaner box.
- Disconnect Connectors: Carefully release the locking tabs on the wiring harness connectors and pull them straight out from the module. Never force them.
- Remove the Old Module: Unbolt the old ECM from its mounting bracket and remove it from the vehicle.
- Install the New Module: Mount your new, pre-programmed ECM in the same location. Securely re-attach the wiring harness connectors, ensuring they click into place.
- Reconnect Battery: Re-attach the negative battery terminal. The vehicle may need to complete a security relearn procedure, which typically involves cycling the key. Consult your owner’s manual for specific instructions if needed.
Verified Compatibility for Your Vehicle
This module is a direct replacement for a wide range of GM vehicles. Please verify your model and options below. This part is a direct replacement for service numbers: 12636659, 12639300, 1263605, 12628993, 12628911, 12625453, 12622175, 12630464, and 12678512.
- Cadillac CTS (2009): 6.2L, (RH front engine compartment)
- Cadillac DTS (2009-2011)
- Cadillac Lucerne (2009-2011): 4.6L, (lower part of air cleaner box)
- Cadillac SRX (2009): 4.6L, (LH engine compartment)
- Cadillac STS (2009): 4.4L or 4.6L, (LH frame rail)
- Cadillac STS (2010): 4.6L, (LH frame rail)
- Cadillac XLR (2009): (RH front engine compartment), ID 12625453 or 12636659
- Chevrolet Colorado (2009)
- Chevrolet Colorado (2010-2012): 2.9L or 3.7L, (RH firewall)
- Chevrolet Corvette (2009): ZR1, (RH engine compartment)
- Chevrolet Trailblazer (2009): 6.0L, (LH engine)
- GMC Canyon (2009)
- GMC Canyon (2010-2012): 2.9L or 3.7L, (RH firewall)
- GMC Envoy (2009): 5.3L, (LH engine)
- Hummer H3 (2009-2010): (RH firewall), 3.7L for 2010
- Saab 9-7X (2009): (LH engine)
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) is essential for us to load the exact, correct GM factory software for your vehicle’s specific engine, transmission, and options. This ensures perfect compatibility and performance right out of the box.
Is this a plug-and-play part?
Yes! Because we program the module to your VIN before shipping, it is ready to be installed without requiring a trip to the dealership for expensive programming. In most cases, it is a direct swap.
Will this fix my check engine light?
If the check engine light is caused by an internal ECM failure (like codes P0601-P0606) or communication faults, this module is the correct fix. It’s crucial to properly diagnose the root cause before ordering.
Is any other programming needed after installation?
In most GM vehicles of this era, no further programming is needed. However, you may need to perform a simple security relearn procedure (often called a Passlock or anti-theft relearn), which can typically be done with the ignition key and doesn’t require special tools.
Do I need to send my old ECM back?
No core charge or return is required for this part. You can recycle your old module locally.