Restore Your Vehicle’s Performance and Reliability
Is your Chevrolet Cobalt, Malibu, or HHR acting up? A persistent Check Engine Light, unexplained stalling, rough idling, or a complete no-start condition can be incredibly frustrating. In my 20+ years of hands-on diagnostics, I’ve seen these symptoms point directly to a failing Powertrain Control Module (PCM) more times than I can count. This isn’t just a part; it’s the central computer for your engine, managing everything from fuel mixture and ignition timing to transmission shifting. When it fails, your vehicle’s performance and reliability suffer dramatically.
This is your direct, hassle-free solution. We are offering a genuine GM-spec PCM, service number 12597125, which is a direct replacement for part number 12635902 and others. The best part? We handle the most critical step for you. Before we ship it, our technicians will program the module with the very latest GM software updates, specifically matched to your vehicle using the VIN you provide at checkout. This means no expensive trips to the dealership for programming, no special tools required—just a straightforward installation to get you back on the road with confidence.
From the Diagnostic Bay: The Intermittent Stall Case
A customer brought in their 2009 Cobalt with a maddening issue: it would stall randomly at red lights, but not always. There were no consistent trouble codes, just a history of random communication faults. We checked fuel pressure, sensors, and wiring harnesses—everything looked fine. From experience, I know that heat soak can cause internal PCM solder joints to fail intermittently. We connected a professional scanner and monitored live data. Sure enough, during a long idle, we saw injector pulse width data start to fluctuate wildly just before it stalled. We swapped in a pre-programmed PCM, and the problem was gone instantly. This simple replacement saved the customer from weeks of chasing phantom issues and the high cost of dealership diagnostics.
Is Your Vehicle Showing These Signs of PCM Failure?
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Diagnostic Trouble Codes (DTCs) related to internal module failure (e.g., P0601, P0606).
- ✔ Communication errors with other modules (U-codes like U0100).
- ✔ Engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Stalling, stumbling, or hesitation during acceleration.
- ✔ Failure to pass state emissions testing.
A Straightforward Guide to Installation
Installing your new 2007-2010 Cobalt PCM is a job most DIYers can handle in under an hour. The key is our pre-programming service, which eliminates the need for dealer-specific tools.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait a few minutes to ensure the system is fully discharged.
- Locate the PCM: On most Cobalts, G5s, and HHRs, the PCM is located in the engine compartment on the driver’s side, often near the fuse box or strut tower. For trucks and vans, it’s typically on the LH side, sometimes under the battery tray.
- Disconnect Connectors: Carefully release the locking tabs on the electrical connectors and pull them straight out from the module. Avoid pulling on the wires themselves.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket. There are usually two or three bolts holding it in place.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and secure it with the bolts.
- Reconnect Everything: Plug the electrical connectors firmly back into the new module until they click into place. Reconnect your negative battery terminal.
- Final Steps: Your vehicle may require a security relearn procedure, which can often be done by cycling the key. Turn the ignition to ‘ON’ for 10 minutes, ‘OFF’ for 10 seconds, and repeat two more times. Then, start the engine. Your vehicle is ready to go!
Verified Vehicle Compatibility
This module is a direct replacement for service numbers 12612397, 12594750, 12597125, 12629019, 12635902, 12611549 and more. It is guaranteed to fit the following vehicles with the specified options. Please provide your VIN at checkout to ensure perfect programming.
COBALT: 2007-2008 (2.2L), 2008 (2.4L), 2009 (2.2L), 2010 (2.2L)
EXPRESS 1500 VAN: 2008-2009 (4.3L)
G5: 2007 (2.2L), 2008-2010
G6: 2008-2009 (2.4L), 2010
HHR: 2007-2011 (2.2L), 2008-2011 (2.4L)
IMPALA: 2010-2011
LUCERNE: 2009-2011 (3.9L)
MALIBU: 2007 (2.2L), 2008 (2.2L Classic & 2.4L New Style), 2009-2010 (2.4L/3.5L), 2011-2012 (2.4L)
SAVANA 1500 VAN: 2008-2009 (4.3L)
SIERRA 1500 PICKUP: 2007 (New Style, 4.3L), 2008 (4.3L), 2009 (4.3L, w/o hybrid)
SILVERADO 1500 PICKUP: 2007 (New Style, 4.3L), 2008 (4.3L), 2009 (4.3L, w/o hybrid)
SKY: 2008-2010 (2.4L)
SOLSTICE: 2008-2010 (2.4L)
VUE: 2008-2010 (2.4L)
Frequently Asked Questions
Why do you need my VIN number?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact software and calibrations your specific vehicle requires. This includes engine size, transmission type, and any other factory options, ensuring seamless communication and performance.
Is this part difficult to install myself?
Not at all for most DIYers. Since we pre-program the module, the installation is a simple mechanical swap. You just need basic hand tools to unbolt the old unit and install the new one. No programming tools are required.
Will this fix my check engine light?
If the check engine light is caused by a faulty PCM (e.g., codes P0601-P0606) or related component failure that the PCM controls, this will resolve the issue. It’s crucial to have your vehicle properly diagnosed to ensure the PCM is the root cause.
What do I need to do after installing the new PCM?
After installation, you may need to perform a simple security relearn procedure, which typically involves cycling the ignition key as described in our installation guide. Some vehicles may also require a Case Relearn (crankshaft position sensor relearn) which can be done by some mechanics or with certain high-end scan tools, though many vehicles run fine without it.
Is this a new or used part?
This is a high-quality, inspected, and tested recycled OEM part that has been verified to meet or exceed original factory specifications. We then load it with fresh, VIN-specific GM software.