Is Your 2004 Blazer or Jimmy Running Rough?
If you’re dealing with a persistent Check Engine Light, erratic shifting, stalling, or a no-start condition, a failing Powertrain Control Module (PCM) is often the culprit. As the central computer for your truck, the PCM manages everything from fuel injection and ignition timing to transmission shift points. When it fails, the symptoms can be confusing and frustrating. I’ve seen countless S10s and Jimmys in my shop where owners have replaced sensors and other parts, only to find the root issue was the PCM itself.
The Direct Solution: A VIN-Programmed PCM
This isn’t just a replacement part; it’s a complete, ready-to-install solution. We take a high-quality replacement PCM, part number 12586243, and flash it with the latest official GM software updates specifically for your vehicle. All we need is your Vehicle Identification Number (VIN) at checkout. This ensures perfect communication between the module and your truck’s systems, restoring original performance and reliability.
A Story from the Shop Floor
A customer’s 2004 Jimmy S15 came in last month with what he was convinced was a failing transmission. It was shifting hard between 1st and 2nd and sometimes wouldn’t shift at all. He’d already spent a fair amount on a fluid flush and a new filter with no change. After hooking up my pro-level scanner, I saw no specific transmission codes, but the data stream from the PCM was inconsistent. The PCM wasn’t correctly commanding the shift solenoids. We installed one of these VIN-programmed PCMs, and the truck drove off shifting as smoothly as it did from the factory. It’s a classic case where the ‘brain’ was the problem, not the mechanical parts.
Common Symptoms of a Failing 2004 Blazer S10 PCM:
- âś” Persistent Check Engine Light (CEL) with various codes
- âś” Harsh or erratic automatic transmission shifting
- âś” Engine stalling, stumbling, or poor idle quality
- âś” A complete no-start condition where the engine cranks but won’t fire
- âś” Poor fuel economy
- âś” Communication errors with diagnostic scan tools
Plug-and-Play Installation: No Dealer Visit Required
Installing your new PCM is a straightforward process you can do in your own driveway. Since we program it beforehand, you won’t need an expensive trip to the dealership for flashing or key relearning procedures. Just follow these simple steps:
- Safety First: Disconnect the negative terminal from your vehicle’s battery to prevent any electrical shorts.
- Locate the Old PCM: On your 2004 Blazer, Jimmy, or S10/Sonoma, the PCM is located in the front right-hand side of the engine compartment, typically near the firewall or inner fender.
- Disconnect the Harnesses: Carefully unclip and remove the electrical wiring harnesses from the old module. Inspect the connectors for any corrosion or bent pins and clean them if necessary.
- Remove the Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install the New PCM: Mount your new, pre-programmed PCM onto the bracket and securely reconnect the wiring harnesses. You should hear a ‘click’ as they lock into place.
- Reconnect the Battery: Re-attach the negative battery terminal. The installation is complete, and your truck is ready to start.
Guaranteed Compatibility
This module is a direct replacement for part numbers 12586243 and 89017739. It is compatible with a wide range of 2004 GM vehicles, including the S10/S15/Sonoma, Blazer/Jimmy, Astro/Safari, and many others. By providing your VIN, you guarantee that the software loaded onto the module is a perfect match for your vehicle’s specific configuration.