Is Your Pontiac G5 Running Rough?
If you’re experiencing frustrating issues like a persistent check engine light, stalling, rough idling, or a complete no-start condition, the problem may lie with a failing Powertrain Control Module (PCM). The PCM is the electronic brain of your vehicle, managing everything from fuel injection and ignition timing to transmission shifting and emissions control. When it starts to fail, it can cause a cascade of confusing and seemingly unrelated problems, making your 2007-2010 Pontiac G5 unreliable and difficult to drive.
Diagnosing a Faulty 2007-2010 G5 PCM
A failing engine computer can mimic many other component failures, leading to costly and time-consuming misdiagnoses. Before you replace sensors or fuel system parts, consider if the core issue is the module itself. A faulty PCM can store false trouble codes, lose communication with diagnostic scan tools, or fail to operate injectors and spark plugs correctly. This can leave even experienced technicians chasing ghosts. Our replacement PCM, part number 12629019, is the definitive solution to restore your vehicle’s performance and reliability.
From the Diagnostic Bay
We had a 2009 Chevy Cobalt (which uses the same family of PCM as the G5) come into the shop with an intermittent no-start condition. The owner had already replaced the battery, starter, and crankshaft position sensor. The car would run fine for days, then suddenly refuse to start. When we connected our scan tool, we found a U0100 ‘Lost Communication with ECM/PCM’ code. After verifying the wiring and grounds were solid, we traced the issue to an internal failure in the PCM. It was losing power internally only when it heated up. Installing a VIN-programmed replacement module like this one solved the problem instantly, saving the customer from further guesswork and expense.
Common Symptoms of a Failing PCM
- ✔ Persistent Check Engine Light (CEL) that won’t clear.
- ✔ Engine stalling or shutting off unexpectedly while driving.
- ✔ Rough or erratic idling and poor engine performance.
- ✔ A significant drop in fuel economy for no apparent reason.
- ✔ The vehicle cranks but refuses to start.
- ✔ Harsh or incorrect automatic transmission shifting.
- ✔ Multiple, unrelated diagnostic trouble codes (DTCs) being stored.
- ✔ Failure to communicate with a standard OBD-II scan tool.
The Plug-and-Play Solution
This isn’t just a part in a box; it’s a complete service. We take the guesswork out of the repair by pre-programming this module to your vehicle’s specific Vehicle Identification Number (VIN). This ensures that all factory settings, security information (anti-theft), and engine parameters are perfectly matched to your car. When you receive the part, the most complex part of the job is already done. This unit is a direct replacement for multiple service numbers, including 12597125, 12612397, 12594750, 12629019, 12635902, and 12611549, providing broad compatibility across a range of GM vehicles like the Cobalt, HHR, Malibu, and more.
Frequently Asked Questions
Do I need to do any programming after I receive this PCM?
No. This PCM comes fully programmed to the VIN you provide at checkout. It is ready for installation right out of the box. In most cases, you will not need a scan tool for any additional setup, though a security relearn procedure may be required on some models, which can typically be done without special tools.
How do I provide my vehicle’s VIN?
After you complete your purchase, you will need to send us your 17-digit VIN. You can typically find this on your vehicle’s dashboard (visible through the windshield on the driver’s side), on your insurance card, or on the driver’s side door jamb sticker.
Will this fix my specific problem?
This module will correct any issues directly caused by a faulty PCM. While we cannot guarantee it will fix all vehicle problems, it is the definitive solution for the common symptoms listed above. We highly recommend a proper diagnosis by a qualified mechanic to confirm the PCM is the point of failure before ordering.
Is this a new part?
This is a high-quality, fully tested replacement part that has been meticulously inspected and prepared to meet or exceed original equipment specifications. We ensure its reliability and performance through rigorous testing procedures.
What vehicles does this part fit?
This PCM fits a wide range of GM vehicles, including the 2007-2010 Pontiac G5, Chevrolet Cobalt, HHR, Malibu, Silverado 1500 (4.3L), Saturn Aura, and more. Please refer to the detailed fitment list on the product page to confirm compatibility with your exact year, make, and model.