Is Your Buick LeSabre Running Rough?
If you’re experiencing frustrating engine problems with your 2003 Buick LeSabre or another compatible GM vehicle, a failing Powertrain Control Module (PCM) could be the culprit. As the central computer for your engine and transmission, the PCM is responsible for managing everything from fuel mixture and ignition timing to transmission shift points and emissions controls. When it starts to fail, it can cause a cascade of issues that are often misdiagnosed, leading to wasted time and money on unnecessary repairs. This replacement module, part number 89017735, is the definitive solution to restore your vehicle’s performance, reliability, and efficiency.
From the Diagnostic Bay
I once had a 2003 Buick Park Avenue come in with an intermittent stalling issue and a check engine light that other shops couldn’t solve. They had replaced the crank sensor, cam sensor, and even the fuel pump. The car would run fine for a day, then stall at a stoplight. After hooking up our diagnostic tools and monitoring live data, we noticed the PCM was intermittently losing communication and dropping injector pulse commands. It wasn’t a sensor issue; the computer itself was failing internally. We installed a VIN-programmed PCM just like this one, performed the security relearn, and the car ran perfectly. The customer was thrilled to finally have a reliable vehicle again after months of chasing ghosts. It’s a classic case of the symptoms pointing one way, but the root cause being the vehicle’s brain.
Common Symptoms of a Failing PCM
A faulty PCM can manifest in various ways. If you’re noticing any of the following problems, it’s a strong indicator that your engine computer needs attention. This is more than just an inconvenience; a failing module can leave you stranded and cause damage to other components, like the catalytic converter.
- ✔ Check Engine Light: Your dashboard is illuminated with a check engine light, often with communication-related codes (U-codes) or internal processor fault codes (P06xx series).
- ✔ Rough Idle or Stalling: The engine idles erratically, surges, or stalls unexpectedly while driving or at a stop.
- ✔ Poor Performance & Fuel Economy: You notice a significant drop in acceleration, power, and miles per gallon (MPG) as the PCM struggles to manage the engine correctly.
- ✔ Erratic Transmission Shifting: The automatic transmission may shift harshly, slip between gears, or get stuck in one gear (limp mode).
- ✔ Engine Misfires: The PCM may fail to properly control the ignition coils or fuel injectors, leading to persistent misfires that don’t resolve after replacing plugs and coils.
- ✔ No-Start Condition: In severe cases, the PCM can fail completely, preventing the engine from starting at all, even though the battery and starter are good.
- ✔ Failed Emissions Test: The vehicle cannot pass a smog or emissions inspection due to PCM-related faults.
The Direct Solution: A Programmed 2003 LeSabre PCM
This isn’t just a generic, off-the-shelf part. We provide a complete, ready-to-install solution tailored specifically to your vehicle. When you purchase this 2003 LeSabre PCM, you are getting a module that has been meticulously prepared for your car. We use your Vehicle Identification Number (VIN) to flash the unit with the latest, most stable software updates directly from GM. This critical step ensures that the module communicates perfectly with all other systems in your vehicle, from the anti-lock brakes to the instrument cluster.
By installing a correctly programmed module, you are not just replacing a broken part; you are restoring the vehicle’s original operating parameters. This process eliminates software glitches, compensates for component wear, and ensures optimal engine and transmission function. The result is a smoother-running, more efficient, and more reliable vehicle.
Guaranteed Compatibility
This Powertrain Control Module is a direct replacement for service numbers 89017735 and 12583826. It is guaranteed to fit and function correctly in the following vehicles:
- 2003 Buick LeSabre (with ID 12583826)
- 2003-2004 Buick Regal
- 2003-2004 Buick Park Avenue
- 2003 Chevrolet Impala (3.8L Engine)
- 2003 Chevrolet Monte Carlo (3.8L Engine)
- 2003 Pontiac Bonneville (with ID 12583826)
- 2003 Pontiac Grand Prix (3.8L Engine, with ID 12583826)
Frequently Asked Questions
Do I need to program this module?
No. We handle all the programming for you before shipment. Simply provide us with your vehicle’s 17-digit VIN during or after checkout, and we will flash the module with the correct GM software for your specific car. It will arrive ready for installation.
Where is the PCM located on my 2003 Buick LeSabre?
On most of these GM models, including the LeSabre, the PCM is located in the left-hand (driver’s side) engine compartment, typically housed within the air filter box assembly for protection from heat and moisture.
What is a VIN and where do I find it?
The VIN is your car’s unique 17-digit Vehicle Identification Number. You can find it on a metal plate on the driver’s side of the dashboard (visible through the windshield), on the driver’s side door jamb sticker, or on your vehicle’s registration and insurance documents.
Will this fix my check engine light?
If the check engine light is caused by an internal failure of the PCM, then yes, this part will resolve the issue and allow the light to be cleared. However, if the light is on due to other failing components (like an oxygen sensor or a bad catalytic converter), those issues will still need to be addressed separately.
Is any special procedure needed after installation?
Yes, in most cases, you will need to perform a security relearn procedure (also known as a VATS relearn) to allow the new PCM to communicate with your vehicle’s anti-theft system. This can often be done without special tools and instructions are widely available online. Some vehicles may also require a Crankshaft Variation Relearn (CASE Relearn) which requires a professional scan tool.
How do I provide you with my VIN?
You can enter your VIN in the notes section at checkout. If you miss it, you can simply reply to your order confirmation email with the 17-digit VIN, and our team will match it to your order.