Is Your GM Vehicle Running Poorly? The PCM Might Be the Culprit.
The Powertrain Control Module (PCM), often called the Engine Control Module (ECM), is the central computer of your vehicle’s engine and transmission. It manages everything from fuel injection and ignition timing to transmission shift points and emissions controls. When it fails, it can cause a wide range of frustrating and difficult-to-diagnose issues. This replacement PCM, part number 89017739, is the definitive solution for restoring the performance and reliability of your 2004-2005 GM car, truck, or SUV.
Unlike a generic part from a local store, this module is not a one-size-fits-all solution. We pre-program it specifically for your vehicle using your unique Vehicle Identification Number (VIN). This critical step ensures that the module has the correct software, calibrations, and anti-theft settings for your exact model, engine, and options. This means no expensive trip to the dealership for programming—it’s ready for installation right out of the box.
From the Diagnostic Bay
We had a 2004 Silverado 2500 with an 8.1L towed in for a ‘no-start’ condition. The owner had already replaced the fuel pump, convinced that was the issue, but it still wouldn’t fire up. After hooking up our scanner, we found no communication with the PCM. A quick check of the powers and grounds at the module confirmed they were good. The PCM itself had failed internally, specifically the driver that controls the fuel pump relay. We installed a VIN-programmed module just like this one, performed the quick security relearn, and the truck roared back to life. It’s a classic case where what seems like a mechanical failure is actually an electronic one.
Common Symptoms of a Failing GM PCM 89017739
- ✔ Persistent Check Engine Light (CEL) with communication-related trouble codes (e.g., U-codes).
- ✔ Engine misfires, stumbles, or stalls unexpectedly.
- ✔ Noticeable decrease in fuel economy.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Complete no-start condition where the engine cranks but won’t fire.
- ✔ Failure to pass state emissions inspections.
- ✔ Intermittent issues that are difficult to replicate.
The Importance of VIN Programming
This GM PCM 89017739 is used across an incredibly diverse lineup of vehicles—from a Cadillac CTS-V to a GMC Savana van. Each of these vehicles has different engine parameters, transmission strategies, and security systems (like GM’s VATS or Passlock). Programming the module with your VIN ensures it knows exactly which vehicle it’s in. This process loads the latest GM-certified software and calibrations, often correcting factory bugs and improving overall performance and efficiency. Attempting to install a non-programmed module will result in a no-start condition due to security mismatches and incorrect operational data.
This module is a direct replacement for part numbers 89017739 and 12586243. Please verify the part number on your original module to ensure compatibility. Our programming service makes this a straightforward repair, saving you time and money.
Frequently Asked Questions
What is the difference between a PCM and an ECM?
The terms are often used interchangeably. Technically, an ECM (Engine Control Module) only controls engine functions. A PCM (Powertrain Control Module) controls both the engine and the transmission. For most GM vehicles from this era, the single unit is a PCM.
How do I provide my vehicle’s VIN?
After placing your order, you will need to send us your 17-digit VIN. You can typically add it as a note during checkout or reply to your order confirmation email. We cannot ship the module until we have this information.
Will I need to do anything after I install it?
In most cases, you will need to perform a simple security relearn procedure. This can typically be done without any special tools and involves a sequence of key turns. Instructions are readily available online for your specific model, or you can contact our support for guidance.
Is this a brand new part?
This is a high-quality, fully tested replacement part that is guaranteed to meet or exceed original equipment specifications. Each unit undergoes rigorous inspection and testing before being programmed and shipped.
Where is the PCM located on my vehicle?
The location varies by model. On many trucks and SUVs like the Silverado or Avalanche, it’s under the battery tray on the driver’s side. On vehicles like the Trailblazer or Envoy, it’s often next to the air filter box. For cars like the CTS or Corvette, it’s typically in the engine compartment on the passenger side.