Is Your Oldsmobile Alero Running Rough?
If you’re experiencing frustrating issues like a persistent Check Engine Light, erratic engine behavior, poor fuel economy, or even a no-start condition in your 1999 Oldsmobile Alero, the culprit is often a failing Powertrain Control Module (PCM). As the central computer of your vehicle, the PCM is responsible for managing everything from fuel injection and ignition timing to transmission shifting. When it begins to fail, it can cause a cascade of problems that are often misdiagnosed, leading to wasted time and money on unnecessary repairs.
This replacement Powertrain Control Module, service number 09356741, is the definitive solution to restore your vehicle’s performance and reliability. It’s not just a part; it’s a complete, plug-and-play fix engineered to get you back on the road with confidence. We take the guesswork out of the equation by programming the module specifically for your vehicle using your VIN. This ensures that all factory settings are correct and the unit communicates flawlessly with your car’s other systems right out of the box.
From the Diagnostic Bay
We had a 1999 Grand Am with the 3.4L V6 come into the shop, a vehicle that shares its core electronics with the Alero. The owner had already replaced the spark plugs, wires, and even a couple of sensors trying to chase down an intermittent misfire and hard shifting. The codes were all over the place. After confirming power and ground to the module were solid, we connected our scope and saw a noisy, inconsistent signal coming from the PCM’s injector drivers. We swapped in a pre-programmed module just like this one, performed a quick security relearn, and the car ran perfectly. It’s a classic case where the “brain” was the problem, not the parts it was controlling.
Symptoms of a Failing 1999 Alero PCM
- ✔ Persistent and illuminated Check Engine Light (CEL)
- ✔ Unexplained drops in fuel efficiency
- ✔ Engine stalling, stumbling, or hesitating during acceleration
- ✔ Harsh or erratic automatic transmission shifting
- ✔ Failure to pass emissions testing
- ✔ The vehicle cranks but refuses to start
- ✔ Communication errors with diagnostic scan tools
The Right Solution, Programmed For You
Don’t settle for a generic, unprogrammed module from a salvage yard that could create more problems than it solves. Our process is simple and effective. After your purchase, you provide us with your vehicle’s VIN. Our technicians then use that information to flash the module with the latest, most stable software updates directly from GM. This ensures optimal engine performance, fuel economy, and transmission function, tailored specifically to your 1999 Alero PCM configuration. This module is a direct replacement for a wide range of GM vehicles from the late 90s, including the Pontiac Grand Am, Buick Century, and Chevrolet Malibu, and is compatible with multiple service numbers including 09356741, 16236757, 9357034, and more.
Installation is straightforward for any competent DIY mechanic or professional technician. Once installed, some vehicles may require a simple security relearn procedure, which can typically be done without special tools. This restores communication between the PCM and your vehicle’s anti-theft system. Getting your car back to factory-spec operation has never been easier.
Frequently Asked Questions
Do I need to do anything after installing this PCM?
While this module comes pre-programmed to your VIN, many GM vehicles of this era require a security relearn procedure (also known as a VATS relearn) to sync the new PCM with your car’s anti-theft system. This procedure is simple and typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating this cycle three times. Specific instructions for your vehicle can be easily found online.
Is this a plug-and-play part?
Yes, because we program it with your vehicle’s VIN before shipping, it is designed to be a plug-and-play solution. After the physical installation and the potential security relearn, no further programming or dealer visits should be necessary.
How do I provide my VIN?
After you complete your purchase, you will receive instructions on how to send us your vehicle’s 17-digit VIN. We cannot ship your part until we receive this information, as the programming is a critical step in the process.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both the engine and the transmission. If the module is faulty, it can send incorrect signals to the transmission solenoids, causing hard shifts, slipping, or delayed engagement. Replacing a faulty PCM often resolves these types of electronic transmission issues.
Is this compatible with other GM cars?
Absolutely. This module, part number 09356741, fits a wide array of 1998 and 1999 GM vehicles, including the Pontiac Grand Am, Buick Regal, Chevy Malibu, and many others as listed in the fitment guide. The key is the VIN-specific programming we provide, which makes it correct for your exact model.