Is Your 2003 Blazer or Jimmy Running Rough?
If you’re dealing with a frustrating no-start condition, erratic idling, poor fuel mileage, or a check engine light that won’t go away, a failing Powertrain Control Module (PCM) is often the culprit. In my 20+ years as a technician, I’ve seen these symptoms countless times on the 4.3L V6 platform. The PCM is the brain of your truck, and when it starts to fail, it can cause a cascade of confusing and hard-to-diagnose issues. This isn’t just an inconvenience; it’s a reliability problem that can leave you stranded.
The Direct-Fit Solution: Programmed and Ready to Install
This Powertrain Control Module is the definitive solution for your 2003 Chevy Blazer, S10, GMC Jimmy, or Sonoma. We take all the guesswork and hassle out of the repair. Before we ship the part, our technicians will program it with the latest official GM software, specifically matched to your vehicle using the VIN you provide. This means it arrives at your door ready for a straightforward installation, saving you a costly trip to the dealership and their programming fees.
Real-World Scenario: A customer’s 2003 GMC Jimmy S15 came into my shop last month. It was stalling at stoplights and had a persistent P0604 (Internal Control Module RAM Error) code. After verifying power and grounds were solid, we knew the original PCM had an internal fault. We installed a VIN-programmed module just like this one. The entire job, including the security relearn, took less than 30 minutes. The customer drove away with a truck that ran like new, completely solving the issue.
Why Choose a VIN-Programmed 2003 Blazer S10 PCM?
- ✔ Eliminate Drivability Problems: Solves common issues like stalling, hesitation, harsh shifting, and inaccurate fuel gauge readings.
- ✔ No Dealer Programming Needed: This module arrives pre-programmed to your exact vehicle. It’s a plug-and-play repair.
- ✔ Latest GM Software: We flash the unit with the most current GM calibrations, which can resolve factory bugs and improve performance and efficiency.
- ✔ Restores Communication: Fixes communication errors between the engine, transmission, and other vehicle systems.
- ✔ Guaranteed Compatibility: By using your VIN, we ensure this module is a perfect match for your truck’s specific options and systems.
Simple Installation Guide
You can do this job yourself with basic hand tools. On the Blazer S10 and Jimmy S15, the PCM is located in the engine bay on the front right (passenger) side.
- Safety First: Disconnect the negative terminal from your vehicle’s battery.
- Locate the PCM: Find the module on the passenger side of the engine compartment, typically near the firewall or inner fender.
- Disconnect Harnesses: Carefully unplug the wiring harness connectors. These often have a lever-lock or slide-lock mechanism. Do not force them.
- Remove Old Module: Unbolt the old PCM from its mounting bracket and remove it from the vehicle.
- Install New Module: Bolt the new, programmed PCM into place.
- Reconnect Everything: Securely plug the wiring harnesses back into the new module until they click. Reconnect the negative battery terminal.
- Security Relearn: In many cases, you will need to perform a simple security relearn procedure. This typically involves turning the key to the ‘ON’ position for 10-15 minutes, then off, and repeating two more times. This allows the new PCM to sync with your vehicle’s anti-theft system.
Vehicle Compatibility Information
This module, part number 12570557, is a direct replacement for a wide range of GM vehicles. Please verify your part number or contact us with your VIN if you are unsure. This part is compatible with service numbers: 12581565, 12570558, 12576106, 12576869, 12578127, 88864822, 89017733 and more.
Fits 2003 Blazer S10 / Jimmy S15 with 4.3L V6, and also fits models such as:
- 2003 Astro / Safari
- 2003 Silverado / Sierra 1500 (4.3L)
- 2003 Silverado / Sierra 2500 & 3500 (8.1L Gasoline)
- 2003 Suburban / Yukon XL 2500 (8.1L)
- 2003 Avalanche 2500
- 2003 Express / Savana Vans (All Engines)
- 2004 Corvette / CTS (with matching ID 12581565)
IMPORTANT: After purchase, please send us your vehicle’s 17-digit VIN to ensure correct programming before shipment. This step is crucial for a successful repair.