Restore Your Vehicle’s Performance and Reliability
Is your Pontiac Aztek or other GM vehicle running rough, stalling unexpectedly, or showing a persistent Check Engine Light? These aren’t just annoyances; they’re often symptoms of a failing Powertrain Control Module (PCM), the computer that serves as your vehicle’s brain. When it falters, everything from fuel economy to transmission shifting can be affected. I’ve spent over two decades diagnosing these exact issues, and a faulty PCM is a common culprit that can mimic a dozen other problems, leading to wasted time and money on unnecessary repairs.
This isn’t just a replacement part; it’s a complete solution. We provide a high-quality PCM, part number 89017735, that is professionally programmed with the latest GM software updates specifically for your vehicle. Simply provide your Vehicle Identification Number (VIN) after purchase, and we handle the complex programming for you. This means no expensive trips to the dealership for flashing. You receive a module that is ready to install, getting you back on the road with confidence.
A Technician’s Notebook: The Ghost in the Grand Am
A few years back, a 2004 Grand Am with the 3.4L V6 came into my shop with a problem that was driving the owner crazy. It had an intermittent hard start and would occasionally stumble at idle. The previous mechanic had already replaced the spark plugs, wires, and even the idle air control valve, but the issue persisted. No hard codes were stored, just a pending P0300 (Random Misfire). Instead of throwing more parts at it, I monitored the live data stream from the PCM. I noticed the fuel trim values were erratically jumping, and the injector pulse width was inconsistent—classic signs the computer itself was struggling. We installed a correctly programmed PCM, and the car ran perfectly. It’s a textbook case of how a failing 2003-2005 Aztek PCM or its equivalent can create phantom issues that seem mechanical but are purely electronic.
Is Your Vehicle Showing These Signs of PCM Failure?
If you’re experiencing any of the following, a faulty engine computer could be the root cause. A failing PCM often stores specific Diagnostic Trouble Codes (DTCs), so a scan can help confirm your diagnosis.
- ✔ Check Engine Light is on with codes like P0601, P0602, or P0606 (Internal Control Module Errors).
- ✔ Your engine cranks but refuses to start.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ Rough or unpredictable automatic transmission shifting.
- ✔ The engine idles poorly, stalls, or stumbles during acceleration.
- ✔ Failure to pass an emissions inspection.
Your Straightforward PCM Installation Guide
Replacing the PCM is a manageable job for a confident DIYer. The module is typically located in the engine bay, often within the air filter housing for easy access. Follow these steps for a successful installation.
- Safety First: Always disconnect the negative terminal from your vehicle’s battery and wait at least 15 minutes for the system capacitors to discharge.
- Locate the PCM: On most compatible vehicles like the Aztek, Rendezvous, and Montana, the PCM is on the driver’s side of the engine compartment, attached to the air cleaner assembly.
- Disconnect the Connectors: Carefully release the locking tabs on the electrical wiring harnesses and pull them straight out from the module. Avoid bending the pins.
- Remove the Old Module: Unbolt the PCM from its mounting bracket. It’s usually held in place by a few small bolts.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely tighten the bolts.
- Reconnect Everything: Firmly plug the wiring harnesses back into the new module until they click into place. Reconnect the negative battery terminal.
- Perform Security Relearn (If Needed): In many cases, a simple 10-30 minute security relearn procedure is required. This typically involves turning the key to the ‘ON’ position for 10 minutes, off for 10 seconds, and repeating two more times. Your vehicle’s service manual will have the exact steps.
Verified Vehicle Compatibility List
This module is a direct replacement for part numbers 12583827 and 12583826. Please verify your vehicle is on this list and, if noted, that the engine size or ID matches for guaranteed compatibility. This part is confirmed to fit the following models:
- Pontiac Aztek: 2003-2005 (LH engine compartment)
- Buick Century: 2003-2005 (LH engine compartment)
- Buick LeSabre: 2004-2005 (LH engine compartment)
- Buick Park Avenue: 2004-2005 (LH front engine compartment)
- Buick Rendezvous: 2003-2005 (LH engine compartment)
- Chevrolet Impala: 2003-2005 (3.4L for 2003)
- Chevrolet Malibu: 2003 (LH dash)
- Chevrolet Monte Carlo: 2003-2005 (3.4L for 2003)
- Chevrolet Venture: 2003-2005 (LH engine compartment)
- Oldsmobile Alero: 2003-2004 (3.4L, LH center dash)
- Oldsmobile Silhouette: 2003-2004 (LH engine compartment)
- Pontiac Bonneville: 2004-2005 (3.8L, LH engine compartment)
- Pontiac Grand Am: 2003-2005 (3.4L, LH center dash)
- Pontiac Grand Prix: 2003 (3.1L, LH front engine compartment)
- Pontiac Montana: 2003-2005 (LH engine compartment)
Frequently Asked Questions
Frequently Asked Questions
Do I need to get this module programmed by a dealer?
No. We program the module to your vehicle’s specific VIN before we ship it. This saves you hundreds in dealership fees and makes the installation process much simpler.
What do you need from me to program the PCM?
After you place your order, you will need to provide us with your 17-digit Vehicle Identification Number (VIN). You can typically find this on your driver’s side dashboard (visible through the windshield) or on your vehicle’s registration or insurance card.
Where is the PCM located on my 2004 Pontiac Aztek?
On the 2003-2005 Aztek, the PCM is located in the engine bay on the driver’s side, mounted to the air filter box assembly for easy access.
Will this fix my transmission shifting problems?
In many cases, yes. The PCM controls both engine and transmission functions. Erratic shifting, getting stuck in gear, or harsh engagement can often be caused by a faulty PCM. This programmed 2003-2005 Aztek PCM is designed to resolve those communication errors.
Is this part difficult to install myself?
For someone with basic mechanical skills and tools, this is a very straightforward replacement. The most important steps are disconnecting the battery and carefully handling the electrical connectors. A security relearn procedure may be necessary, which is simple to perform.