Restore Peak Performance to Your GM Vehicle
If you’re dealing with frustrating issues like a persistent Check Engine Light, erratic engine behavior, poor fuel mileage, or even a no-start condition, the cause is often the vehicle’s central computer: the Powertrain Control Module (PCM). As an experienced technician, I’ve seen countless GM vehicles from this era develop these exact problems. The PCM is the brain of your engine and transmission, and when it fails, it can create a diagnostic nightmare. This isn’t just a part; it’s the solution to getting your car running smoothly and reliably again.
This replacement PCM, part number 89017735, is the definitive fix for your 2004-2005 Buick Park Avenue and a wide range of other GM models. We take the guesswork and high dealership costs out of the equation. Before we ship your module, we flash it with the latest official GM software, precisely matched to your vehicle using the VIN you provide. This means it arrives at your door ready for a straightforward installation, saving you hundreds in programming fees and a trip to the service center.
A Technician’s Notebook
I remember a 2005 Buick LeSabre that came into my bay with a complaint of intermittent stalling at stoplights, but only when the engine was fully warmed up. The owner had already replaced the plugs, wires, and a few sensors with no luck. No hard codes were stored, just a pending P0606 (PCM Processor Fault) that would never set the light. After checking all the wiring, I suspected a heat-soaked PCM. We swapped in a pre-programmed module just like this one, and the problem vanished instantly. These internal failures are common and can be nearly impossible to track down without simply replacing the faulty unit.
Is Your Vehicle Showing These Symptoms?
A failing PCM can manifest in various ways. If you’re experiencing any of the following, a faulty module is a likely culprit:
- ✔ Check Engine Light is illuminated with codes like P0601 (Internal Memory Error) or P0606 (PCM Processor Fault).
- ✔ The engine cranks but refuses to start.
- ✔ Unexplained drops in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ The engine stumbles, misfires, or stalls unexpectedly.
- ✔ Communication errors with your scan tool.
A Straightforward Guide to Installation
Installing your new 2004-2005 Park Avenue PCM is a job most DIYers can handle. Since we program it for you, no special scan tools are needed for setup—just a basic security relearn procedure that takes about 30 minutes.
- Safety First: Disconnect the negative terminal from your vehicle’s battery and secure it away from the post.
- Locate the PCM: On most of these vehicles, including the Park Avenue, the PCM is located in the engine bay, typically inside the air filter box housing on the driver’s side (LH side).
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that must be released. Once disconnected, unbolt the old PCM and remove it.
- Install the New Module: Seat the new PCM in the mounting bracket and bolt it down securely. Reconnect the electrical harnesses, ensuring they click into place.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Security Relearn: This is a critical step. Turn the key to the ‘ON’ position (don’t start the engine) for 10-12 minutes, or until the security light stops flashing and turns off. Turn the key ‘OFF’ for 10 seconds. Repeat this cycle two more times (for a total of three cycles). After the third cycle, the vehicle will start and run with the new PCM.
Verified Vehicle Compatibility
This module is a direct replacement for part numbers 12583827 and 12583826. It is guaranteed to fit the following vehicles. Please verify your specific model and options.
- Alero: 2003 (3.4L, ID 12583827), 2004 (3.4L)
- Aztek: 2003 (ID 12583827), 2004-2005
- Bonneville: 2004-2005 (3.8L)
- Century: 2003-2005
- Grand Am: 2003 (3.4L, ID 12583827), 2004-2005 (3.4L)
- Grand Prix: 2003 (3.1L, ID 12583827)
- Impala: 2003 (3.4L, ID 12583827), 2004-2005
- LeSabre: 2004-2005
- Malibu: 2003 (ID 12583827)
- Monte Carlo: 2003 (3.4L, ID 12583827), 2004-2005
- Montana: 2003-2004, 2005 (Base)
- Park Avenue: 2004 (ID 12583827), 2005
- Rendezvous: 2003-2005 (ID 12583827)
- Silhouette: 2003-2004
- Venture: 2003 (ID 12583827), 2004-2005
Frequently Asked Questions
What happens after I place my order?
After your purchase, you will need to send us your vehicle’s 17-digit VIN. We cannot ship the module until we have this information. Once we receive your VIN, we will program the PCM with the latest GM software for your exact vehicle and ship it out to you.
Do I need to do anything after installing the PCM?
Yes. You must perform a standard GM security relearn procedure, which involves cycling the key. This procedure is detailed in our installation guide and does not require any special tools. It syncs the new PCM with your vehicle’s anti-theft system.
Where is the PCM located on my 2004-2005 Park Avenue?
On the Buick Park Avenue, the PCM is typically housed inside the air cleaner assembly on the driver’s side of the engine compartment. This location helps protect it, but it’s still susceptible to heat and vibration over time.
Will this fix my car’s hard shifting?
In many cases, yes. The PCM controls transmission line pressure and shift points based on data from various sensors. If the PCM is faulty, it can cause erratic or harsh shifting. Replacing a bad PCM often resolves these transmission-related symptoms.
How do I find my VIN?
Your 17-digit Vehicle Identification Number (VIN) can be found on your vehicle’s registration, insurance card, or on a metal plate on the driver’s side of the dashboard, visible through the windshield.