Is Your GM 3.8L Vehicle Running Rough?
If your 2003 Pontiac Bonneville, Impala, Grand Prix, or other compatible GM vehicle is suffering from mysterious and frustrating issues, a failing Powertrain Control Module (PCM) is often the culprit. This component is the central brain of your vehicle, managing everything from fuel injection and spark timing to transmission shift points and emissions controls. When it begins to fail, it can create a cascade of problems that are difficult to diagnose, leading to wasted time and money on unnecessary repairs.
Symptoms of a Failing Powertrain Control Module
- ✔ Check Engine Light: The most common sign. You may see codes related to various sensors, misfires, or communication errors.
- ✔ Poor Engine Performance: Noticeable loss of power, hesitation during acceleration, or a significant drop in fuel economy.
- ✔ Erratic Shifting: The transmission may shift harshly, late, or get stuck in one gear (limp mode).
- ✔ Engine Stalling or Rough Idle: The engine might stall unexpectedly at stops or idle erratically, surging up and down.
- ✔ No-Start Condition: In severe cases, the vehicle may crank but refuse to start because the PCM isn’t commanding fuel or spark.
- ✔ Failed Emissions Test: A faulty PCM can prevent the emissions system monitors from running correctly, leading to an automatic failure.
The Direct-Fit Solution: A Programmed 2003 Bonneville PCM
Don’t let a faulty computer keep your car off the road. This Powertrain Control Module, service number 89017735, is the definitive solution for your vehicle. We take the guesswork out of the repair by pre-programming the module specifically for your car using the Vehicle Identification Number (VIN) you provide. This ensures that all factory settings, engine parameters, and transmission strategies are perfectly matched to your vehicle’s original specifications. We also load the latest available software updates from GM, which can resolve common drivability issues and improve overall performance and efficiency.
This is not a generic, one-size-fits-all part. It’s a tailored solution designed for a seamless installation. Once installed, you will need to perform a simple security relearn procedure (often called a VATS relearn) to sync the new module with your vehicle’s anti-theft system. This can typically be done in your driveway without any special tools.
Complete Vehicle Compatibility
This module is a direct replacement for service numbers 89017735 and 12583826. It is confirmed to fit the following vehicles:
- Pontiac Bonneville: 2003 (3.8L Engine)
- Pontiac Grand Prix: 2003 (3.8L Engine)
- Buick LeSabre: 2003
- Buick Park Avenue: 2003, 2004
- Buick Regal: 2003, 2004
- Chevrolet Impala: 2003 (3.8L Engine)
- Chevrolet Monte Carlo: 2003 (3.8L Engine)
Please verify your original part number or contact us with your VIN to ensure perfect compatibility before ordering.
Frequently Asked Questions
What is a PCM and what does it do?
The Powertrain Control Module (PCM) is your car’s main computer. It controls all aspects of the engine and transmission to ensure optimal performance, fuel economy, and emissions.
How do I provide my VIN for programming?
After you complete your purchase, you can send us a message with your 17-digit VIN. We cannot ship your part until we receive this information, as the programming is essential for the part to function in your vehicle.
Is this part difficult to install?
The physical installation is straightforward for someone with basic mechanical skills. The PCM is typically located in the air filter box in the LH (driver’s side) engine compartment. It involves disconnecting the battery, unplugging a few electrical connectors, and swapping the module. The most critical step is the security relearn procedure after installation.
What is the security relearn procedure?
This is a simple procedure that syncs the new PCM to your car’s anti-theft system. It usually involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’ for 10 seconds, and repeating this cycle three times. Your vehicle’s service manual will have the exact steps, or you can easily find instructions online for your specific model.
Will this fix my check engine light?
If the check engine light and other symptoms are caused by a faulty PCM, this part is the correct solution. However, it’s always best to have your vehicle properly diagnosed to rule out other potential issues like failed sensors or wiring problems. This module will solve any issues originating from the computer itself.