Is Your Pontiac Running Rough? Get a Reliable Solution.
If you’re dealing with a frustrating check engine light, poor fuel economy, a rough idle, or even a no-start condition in your 2003 Pontiac Bonneville, a failing Powertrain Control Module (PCM) is often the culprit. As the brain of your engine, when the PCM falters, it can create a cascade of confusing and costly problems. Instead of guessing with sensor replacements, get the definitive fix with our professionally programmed PCM, designed to restore your vehicle’s performance and reliability.
Real-World Diagnostics: A Story from the Shop
“A customer’s 2003 Grand Prix with the 3.8L engine—which uses this exact same PCM—came into my shop last month. The owner had already replaced two oxygen sensors trying to clear a persistent code, but the check engine light kept coming back. After a quick diagnostic check, I found the heater circuit driver inside the original PCM had failed. It wasn’t the sensor at all; the computer simply couldn’t operate it correctly anymore. We installed one of our pre-programmed modules, and the problem was solved in under 30 minutes. This is a classic case I’ve seen dozens of times on these GM platforms.”
The Direct-Fit, No-Hassle 2003 Bonneville PCM
This isn’t just a replacement part; it’s a complete service. We take the guesswork out of the repair by programming this module specifically for your vehicle using your VIN. This ensures all factory settings and the latest GM software updates are loaded, making the installation process as simple as possible.
- ✔ Eliminate Drivability Issues: Solves common problems like stalling, hesitation, harsh shifting, and inaccurate fuel gauge readings.
- ✔ Pass Emissions Testing: A faulty PCM is a common reason for failing an emissions test. This will restore proper system function.
- ✔ VIN-Programmed for Your Car: We flash the module with your vehicle’s specific information, ensuring perfect communication with other onboard systems.
- ✔ No Dealer Required: This module arrives ready for installation, saving you the time, cost, and hassle of a dealership visit for programming.
Simple Installation Process
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the Old PCM: On most compatible models, the PCM is found in the engine bay, typically on the driver’s side inside the air filter housing.
- Disconnect and Remove: Carefully unplug the wiring harness connectors. Use a small screwdriver to release the locking tabs if necessary. Then, unbolt the module from its mounting bracket.
- Install the New Module: Seat the new PCM in the bracket and securely fasten the bolts. Reconnect the wiring harnesses, ensuring they click firmly into place.
- Reconnect Battery: Re-attach the negative battery terminal. The vehicle is now ready to start.
Guaranteed Fitment for Your Vehicle
This Powertrain Control Module is a direct replacement for service numbers 12583826 and 89017735. It is guaranteed to be compatible with the following vehicles:
- 2003 Pontiac Bonneville (with ID 12583826)
- 2003 Pontiac Grand Prix (3.8L, with ID 12583826)
- 2003-2004 Buick Regal
- 2003-2004 Buick Park Avenue
- 2003 Buick LeSabre (with ID 12583826)
- 2003 Chevrolet Impala (3.8L, with ID 12583826 or 89017735)
- 2003 Chevrolet Monte Carlo (3.8L, with ID 12583826)
IMPORTANT: After your purchase, please provide us with your vehicle’s VIN. We cannot ship your order until we have this information to complete the essential programming service.