Is Your Grand Am Running Rough? The PCM Might Be the Culprit.
If your 2003, 2004, or 2005 Pontiac Grand Am is experiencing frustrating issues like a persistent Check Engine Light, poor fuel economy, erratic shifting, or even a no-start condition, the problem may lie with its most critical component: the Powertrain Control Module (PCM). As the central computer for your engine and transmission, a failing PCM can cause a wide range of performance problems that can be difficult to diagnose. This isn’t just an inconvenience; it affects your vehicle’s reliability, safety, and efficiency.
This replacement Powertrain Control Module, part number 89017735, is the definitive solution to restore your vehicle’s factory performance. We take the guesswork and hassle out of the repair process. Unlike a generic module from a parts store, this unit comes fully programmed to your vehicle’s specific Vehicle Identification Number (VIN). We load the latest, most stable software updates from GM, ensuring optimal communication between all your vehicle’s systems. This VIN-specific programming is crucial for proper function and avoids the costly trip to a dealership for flashing.
From the Diagnostic Bay
We had a 2004 Grand Am 3.4L come into the shop with a bizarre set of symptoms. The owner complained of random stalling at stoplights and a transmission that seemed to shift harshly between first and second gear, but only when warm. There were no consistent trouble codes, just a generic U-code for lost communication that would pop up occasionally. We checked wiring, sensors, and even the transmission fluid. Everything looked fine. On a hunch, we monitored the PCM’s data stream and noticed the processor would occasionally drop sensor readings for a split second. We swapped in a VIN-programmed PCM, and it was like a new car. The stalling vanished, the shifts smoothed out, and the owner was thrilled. It’s a classic case of how a failing computer can mimic a dozen other mechanical problems.
Symptoms of a Failing 2003-2005 Grand Am PCM
A faulty PCM can manifest in numerous ways. If you’re noticing any of the following, it’s a strong indicator that your engine’s computer needs attention:
- ✔ Illuminated Check Engine Light: Often the first sign, with codes related to sensors, emissions, or internal module failure.
- ✔ Poor Engine Performance: Noticeable loss of power, hesitation during acceleration, or rough idling.
- ✔ Reduced Fuel Economy: The engine may run too rich or too lean, causing you to visit the gas station more often.
- ✔ Inconsistent or Harsh Shifting: The PCM controls transmission shift points. A failure can lead to jerky shifts or getting stuck in a gear.
- ✔ Engine Stalling or Misfiring: The module may fail to correctly manage fuel injection or ignition timing, leading to stalls.
- ✔ Vehicle Won’t Start: In cases of complete failure, the PCM may not activate the fuel pump or ignition system, preventing the car from starting at all.
A True Plug-and-Play Solution
Getting your vehicle back on the road shouldn’t require complex procedures or expensive dealer tools. Our process is designed for the everyday driver and the professional mechanic alike. Simply provide us with your VIN during checkout, and our technicians will handle the programming. When the module arrives, installation is straightforward. In most cases, you will need to perform a simple security relearn procedure, which can be done without any special tools and typically takes about 30 minutes. This ensures the new PCM communicates correctly with your vehicle’s anti-theft system.
This module is a direct replacement for original part numbers 89017735, 12583827, and 12583826 and fits a wide array of GM vehicles beyond the Grand Am, including the Chevy Impala, Buick Century, Pontiac Aztek, and more. Please check the detailed fitment list to confirm compatibility with your exact model and year.
Frequently Asked Questions
Will this PCM be ready to install out of the box?
Yes, this module is shipped fully programmed to your vehicle’s VIN with the latest GM software updates. After installation, you may need to perform a standard security relearn procedure, which syncs the module with your car’s anti-theft system. Instructions for this are readily available online and do not require special tools.
What information do you need from me?
We require your vehicle’s 17-digit Vehicle Identification Number (VIN) to program the module correctly. Please provide your VIN at checkout or send it to us immediately after your purchase to avoid shipping delays.
Where is the PCM located on my 2004 Grand Am?
For the 2003-2005 Pontiac Grand Am, the Powertrain Control Module is typically located on the left-hand (driver’s) side, in the center of the dash. Access may require removing a few interior trim panels.
How do I confirm this part will fit my vehicle?
This module replaces part numbers 89017735, 12583827, and 12583826. Please review the comprehensive fitment list on this page. The most reliable way to ensure compatibility is to match the part number from your original module to one of these numbers.
Do I need to send my old PCM back?
No core charge is required for this part. You can keep your old module or dispose of it responsibly.