If your GM vehicle is suffering from a persistent check engine light, erratic engine behavior, or a frustrating no-start condition, the culprit is often the very brain of your engine: the Powertrain Control Module (PCM). As a technician with over two decades of experience under the hood, I’ve seen firsthand how a failing PCM can cause a cascade of confusing issues. This isn’t just a part; it’s the central command center for your engine’s performance, fuel economy, and emissions. This replacement PCM, part number 89017735, is the definitive solution to restore your vehicle’s reliability and drivability.
We take the guesswork and dealership hassle out of the equation. Unlike sourcing a part from a salvage yard or a generic retailer, we program this module specifically for your vehicle using your VIN. This critical step ensures all communications between the engine, transmission, and other onboard systems are perfectly synchronized. We load the latest GM-certified software, which often includes improvements for performance and longevity that your original module may have lacked. This is the closest you can get to a factory-fresh start for your vehicle’s electronics.
A Technician’s Notebook: The Phantom Stall
I remember a 2004 Impala that came into the shop with an intermittent stalling problem that was driving the owner crazy. It would die at stoplights without warning, but then start right back up. There were no consistent trouble codes, just a history of random communication faults. After hours of checking wiring and sensors, we hooked up a scope to the PCM’s power and ground feeds. We saw a momentary voltage drop inside the module itself right before a stall event—a classic sign of internal PCM failure. We swapped in a pre-programmed module like this one, performed the security relearn, and the problem was gone for good. It’s a reminder that sometimes, the most baffling issues trace back to a faulty computer.
Key Signs of a Failing GM PCM
A faulty PCM can manifest in numerous ways. If you’re experiencing any of the following, it’s time to consider a replacement. Look out for:
- ✔ Check Engine Light (CEL) is illuminated with codes like P0601 (Internal Control Module Memory Check Sum Error) or P0606 (PCM Processor Fault).
- ✔ Unexplained drops in fuel economy.
- ✔ The engine cranks but refuses to start.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Intermittent stalling or rough idling for no apparent reason.
- ✔ Failure to pass an emissions test.
A Straightforward Guide to Installation
Replacing the PCM on these GM vehicles is a manageable job for a confident DIYer. While a security relearn procedure is required, it doesn’t necessitate a trip to the dealer. Here’s a general guide:
- Safety First: Always disconnect the negative terminal from your vehicle’s battery before starting any electrical work.
- Locate the PCM: On most of these models, the PCM is found in the engine compartment, typically on the driver’s side (LH), often near the air filter box. On some models like the Grand Am or Alero, it’s located inside under the dash.
- Disconnect and Remove: Carefully unplug the electrical connectors. They have locking tabs that need to be released. Once disconnected, unbolt the module from its mounting bracket and remove it from the vehicle.
- Install the New Module: Bolt the new, pre-programmed PCM into place. Reconnect the electrical harnesses, ensuring they click securely into position.
- Reconnect Battery: Reattach the negative battery terminal.
- Perform Security Relearn (Crucial Step): You will need to perform a security relearn procedure (often called a Passlock or Passkey relearn) to allow the vehicle to start. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then ‘OFF’, and repeating this cycle three times. Your vehicle’s specific procedure can be easily found online.
Will This Fit My Vehicle?
This module is a direct replacement for part numbers 89017735, 12583827, and 12583826. It is guaranteed to be compatible with the following makes and models:
- 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
- Monte Carlo: 2003-2005
- Montana: 2003-2005
- Park Avenue: 2004-2005
- Rendezvous: 2003-2005
- Silhouette: 2003-2004
- Venture: 2003-2005
Please provide your VIN upon purchase so we can ensure perfect programming for your specific vehicle.
Frequently Asked Questions
Why do you need my VIN?
Your Vehicle Identification Number (VIN) allows us to program the PCM with the exact software and calibrations for your car’s specific engine, transmission, and options. This ensures seamless operation and is a critical step for a successful repair.
Is this part difficult to install?
For most DIYers with basic tools, the physical installation is straightforward. The most important part is performing the security relearn procedure after installation, which allows your vehicle’s anti-theft system to recognize the new module. This procedure does not require special tools.
What happens if I don’t do the security relearn?
If the security relearn is not performed, your vehicle’s anti-theft system will activate, and the engine will not start. It’s a mandatory step to sync the new PCM with your vehicle.
My original part number is 12583827. Will this work?
Yes. This module, 89017735, is a fully compatible and interchangeable replacement for part numbers 12583827 and 12583826. It will function identically once programmed to your VIN.
Will this fix my car’s hard shifting problem?
In many cases, yes. The PCM controls transmission shift points and line pressure. If the module is failing, it can cause erratic or harsh shifting. Replacing a faulty PCM is a common fix for these symptoms.