Is Your Chevrolet Impala Running Rough? The PCM Might Be the Culprit.
The Powertrain Control Module, or PCM, is the central command center for your vehicle’s engine and transmission. It processes data from dozens of sensors to manage everything from fuel injection and ignition timing to transmission shift points and emissions controls. When this critical component begins to fail, it can cause a wide range of confusing and frustrating problems, often leading to incorrect diagnoses and wasted money on unnecessary parts. If your 2003, 2004, or 2005 Impala, Monte Carlo, or other compatible GM vehicle is experiencing erratic behavior, this pre-programmed PCM is the definitive solution to restore its performance and reliability.
From the Diagnostic Bay
We had a 2004 Buick Century come into the shop with a complaint of harsh shifting and an intermittent check engine light for a transmission solenoid code. The owner had already replaced the solenoid twice at another shop with no success. After hooking up our diagnostic scanner, we noticed that the command signals from the PCM were erratic, dropping out intermittently. Instead of throwing more transmission parts at it, we identified the root cause: a failing driver circuit inside the original PCM. We installed one of our VIN-programmed modules, performed a quick security relearn, and the car shifted perfectly. The customer was thrilled to finally have a real solution after months of frustration.
Common Symptoms of a Failing PCM
A faulty PCM can manifest in numerous ways. If you’re noticing any of the following issues, it’s a strong indicator that your vehicle’s main computer needs attention. This 2003-2005 Impala Powertrain Control Module is designed to correct these exact problems.
- ✔ Unexplained Check Engine Light (CEL) illumination, often with communication-related (U-codes) or internal processor fault codes.
- ✔ Poor engine performance, including misfires, hesitation, or stalling.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Reduced fuel economy for no apparent reason.
- ✔ The vehicle cranks but refuses to start.
- ✔ Failure to communicate with a diagnostic scan tool.
- ✔ Intermittent issues that seem to have no logical cause.
The Plug-and-Play Solution: A Pre-Programmed Module
Replacing a PCM isn’t as simple as swapping the part. Modern vehicle electronics are complex and require precise software that matches your car’s specific options and Vehicle Identification Number (VIN). Our process eliminates the guesswork and the need for expensive dealership programming. When you order from us, we flash this module with the latest GM-certified software calibration for your exact VIN. This ensures that all systems, including the engine, transmission, and anti-theft system, function exactly as the manufacturer intended. This is the most reliable and efficient way to get your vehicle back on the road.
Why Choose Our 2003-2005 Impala Powertrain Control Module?
This isn’t just a replacement part; it’s a complete solution. By providing us with your VIN upon purchase, you receive a module that is ready for installation right out of the box. It directly replaces original part numbers 89017735, 12583827, and 12583826, covering a wide range of GM vehicles. After installation, a simple security relearn procedure (often called a ‘key-on/key-off’ cycle) may be required to sync the module with your vehicle’s keys, a process that can typically be done in your own driveway without special tools.
Complete Vehicle Fitment List
This module is a direct fit for the following vehicles. Please verify your model and options to ensure compatibility.
- ALERO: 2003-2004 (3.4L)
- AZTEK: 2003-2005
- BONNEVILLE: 2004-2005 (3.8L)
- CENTURY: 2003-2005
- GRAND AM: 2003-2005 (3.4L)
- GRAND PRIX: 2003 (3.1L)
- IMPALA: 2003-2005
- LESABRE: 2004-2005
- MALIBU: 2003
- MONTANA: 2003-2005
- MONTE CARLO: 2003-2005
- PARK AVENUE: 2004-2005
- RENDEZVOUS: 2003-2005
- SILHOUETTE: 2003-2004
- VENTURE: 2003-2005
Frequently Asked Questions
Do I need to send my old module in?
No, there is no core charge or need to send your original part to us. This is a direct replacement part that you purchase outright.
What happens after I place my order?
After you complete your purchase, you will need to provide us with your vehicle’s 17-digit VIN. We cannot program and ship the module without it. Once we have your VIN, we will program the module with the latest GM software and ship it to you.
Is any additional programming required after installation?
In most cases, the only procedure needed after installation is a security relearn, which pairs the module to your keys. This can usually be done without any special tools. In some cases, a Crankshaft Variation Relearn (CASE) may be needed, which requires a compatible scan tool.
How do I find my VIN?
Your VIN can be found on your vehicle’s registration, insurance card, or on a small plate on the driver’s side of the dashboard, visible through the windshield.
Does this part come with a warranty?
Yes, all of our electronic modules come with a standard warranty against defects. Please see our warranty page for complete details and terms.