Is Your 2004 GM Truck or SUV Running Rough?
If you’re dealing with a persistent check engine light, poor fuel economy, erratic shifting, or a no-start condition, the problem might be the brain of your vehicle: the Powertrain Control Module (PCM). This vital component manages everything from fuel injection and ignition timing to transmission shift points. When it fails, it can cause a cascade of frustrating and difficult-to-diagnose issues. Don’t let a faulty computer keep your reliable truck off the road. This is your direct-fit, professionally programmed solution.
From the Diagnostic Bay
We recently had a 2004 Silverado 2500 come into the shop. The owner had spent a small fortune replacing sensors—O2 sensors, a mass airflow sensor, even a throttle position sensor—chasing a P0171 (System Too Lean) code that just wouldn’t clear. The truck idled poorly and hesitated on acceleration. After confirming the new parts were working, we hooked up our professional scan tool and monitored the live data. The fuel trims were completely erratic, a classic sign that the PCM itself was making incorrect calculations. We installed a VIN-programmed module just like this one, performed the security relearn, and the truck ran like new. The customer could have saved hundreds of dollars and weeks of frustration by starting with the vehicle’s central computer.
Symptoms of a Failing PCM
- ✔ Check Engine Light is on with various, often inconsistent, trouble codes.
- ✔ Your vehicle fails to start or starts intermittently.
- ✔ Noticeable decrease in fuel efficiency.
- ✔ The engine stutters, stalls, or misfires while driving.
- ✔ Harsh or erratic automatic transmission shifting.
- ✔ Communication errors with diagnostic scan tools.
- ✔ Failure to pass an emissions test.
The Right Solution for Your 2004 Sierra 3500 PCM
This isn’t just a generic, off-the-shelf part. This is a genuine GM Powertrain Control Module, service number 12586242, that will be professionally programmed to your vehicle’s specific Vehicle Identification Number (VIN). This critical step ensures that the computer has the correct software and calibrations for your truck’s engine, transmission, and factory options. We flash it with the latest updates available from GM, which can often resolve issues that were present even when the vehicle was new. This means you get a component that is ready to install, saving you a costly trip to the dealership for programming.
Guaranteed Compatibility and Simple Installation
This module is a direct replacement for a wide range of 2004 GM trucks and SUVs. It is compatible with service numbers 12586242, 19299226, 89017738, YFKD, YFKF, YFKH, YFKJ, YFKX, YFXL, YFXM, YFXN, YFXP, and YHTN. After installation, a simple security relearn procedure is typically required, which pairs the new module to your vehicle’s anti-theft system. This procedure can usually be done in your driveway without any special tools. Once completed, your vehicle will be back to factory-spec operation.
Frequently Asked Questions
Do I need to get this PCM programmed?
No. We handle the programming for you before we ship the part. Simply provide your vehicle’s 17-digit VIN during or after checkout, and we will flash the module with the latest GM software specific to your truck.
What is a security relearn procedure?
The security relearn, or anti-theft relearn, is a simple process that syncs the new PCM with your vehicle’s existing keys and security system. It typically involves a sequence of turning the key to the ‘ON’ position for about 10-15 minutes, three times in a row. Instructions are readily available online for your specific model and will be included with your part.
Where is the PCM located on my vehicle?
On most 2004 GM full-size trucks and SUVs like the Sierra, Silverado, Tahoe, and Escalade, the PCM is located in the engine bay on the driver’s side, under or near the battery tray. On mid-size SUVs like the Trailblazer and Envoy, it’s typically found next to the air filter box.
How do I find my vehicle’s VIN?
Your 17-digit VIN can be found on a metal plate on the driver’s side 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 transmission shifting problems?
In many cases, yes. The PCM controls both the engine and the transmission. If the module is failing, it can send incorrect signals to the transmission, causing harsh shifts, delayed engagement, or failure to shift. If the transmission itself is mechanically sound, a new PCM is often the solution to these electronic issues.